Editing Coffee filter

{{Short description|Coffee brewing utensil}}
{{Redirect|Coffee filter bag|containers for shipping and storing coffee beans|Coffee bag}}
{{Redirect|Blitzfilter|filters for photographic flashes|flash filter}}
{{Expand German|Kaffeefilter|date=January 2023}}
{{Use dmy dates|date=March 2023|cs1-dates=y}}
[[File:Die Chemex 6 Cup.jpg|thumb|Ground coffee being poured into a paper filter inserted in a [[Chemex]] filter holder and caraffe]]
A '''coffee filter''' is a [[filtration|filter]] used for various [[coffee brewing]] methods including but not limited to [[drip coffee filtering]]. Filters made of [[filter paper|paper]] ([[disposable product|disposable]]), cloth (reusable), or plastic, metal or porcelain (permanent) are used.<ref group="nb" name="NB_Health"/> Paper and cloth filters require the use of some kind of filter holder, whereas filters made out of other materials may present an integral part of the holder or not, depending on construction. The filter allows the liquid coffee to flow through, but traps the coffee grounds.

==Overview==
[[File:Coffee Filter 2006 09 09.JPG|thumb|Used coffee filter]]
[[File:Coffeefilterar.jpg|thumb|Micro photo of a paper filter]]
Paper filters remove oily components called [[diterpenes]] (like [[cafestol]] and [[kahweol]]).<ref name="Gloess-Schönbächler-Klopprogge-DAmbrosio-Chatelain-Bongartz-Strittmatter-Rast-Yeretzian_2013"/> Metal, nylon or porcelain mesh filters do not remove these components.<ref name="Cornelis-El-Sohemy_2007"/><ref group="nb" name="NB_Health"/> These organic compounds, present in unfiltered coffee, have anti-inflammatory properties.<ref name="Cárdenas-Quesada-Medina_2011"/><ref group="nb" name="NB_Cafestol"/> Several studies also indicate that the mild consumption of paper-filtered coffee may reduce the risk of [[coronary heart disease]] due to reducing these compounds.<ref name="Tverdal-Selmer-Cohen-Thelle_2020"/><!-- Filtered coffee was linked to a 15% reduced risk of death from any cause, a 12% decreased risk of death from cardiovascular disease in men and a 20% lowered risk of death from heart disease in women when compared to drinking no coffee." --><ref name="LaMotte_2020"/>

Coffee filters of [[paper]] are made from about 100&nbsp;g/m<sup>2</sup> [[filter paper]]. The raw materials ([[pulp (paper)|pulp]]) for the filter paper are coarse [[softwood|long fiber]], often from fast-growing trees, e.g. Melitta uses up to 60% of [[bambus]] in their filters since 1998.<ref name="Melitta_1"/> Both [[Bleaching of wood pulp|bleached]] and unbleached filters are made.<ref name="Paulapuro_2000">{{cite book |author-last=Paulapuro |author-first=Hannu Viljami |author-link=:fi:Hannu Paulapuro |title=Paper and Board grades |series=Papermaking Science and Technology |volume=18 |date=2000 |publisher=Fapet Oy |location=Finland |isbn=952-5216-18-7 |page=114 |chapter=5}}</ref>

Typically, coffee filters are made up of filaments approximately 20 micrometres wide, which allow particles through that are less than approximately 10 to 15 micrometres.<ref>{{cite web |title=Mixtures and Solutions – Coffee Filter and Diatomaceous Earth |publisher=Princeton Materials Institute, Princeton University |date=2003 |work=Science Curriculum Support Project |url=http://www.princeton.edu/~pccm/outreach/scsp/mixturesandsolutions/diatoms/coffee_filter.html |url-status=dead |archive-url=https://web.archive.org/web/20120107175722/http://www.princeton.edu/~pccm/outreach/scsp/mixturesandsolutions/diatoms/coffee_filter.html |archive-date=2012-01-07}}</ref><ref>{{cite web |url=http://www.mcnallyinstitute.com/09-html/09-07.html |title=Seal face lubrication |publisher=McNally Institute |url-status=dead |archive-url=https://web.archive.org/web/20110110194033/http://www.mcnallyinstitute.com/09-html/09-07.html |archive-date=2011-01-10}}</ref>

Some baristas claim that paper filters exhibit a "paperish" taste<ref name="Rosenthal_Cup-filter"/> and recommend to wash out the filter with a flush of hot water before filling the ground coffee into the filter.

Since paper filters filter out some components the resulting coffee is said to taste somewhat fruitier compared to permanent filters.

For a filter to be compatible with a [[filter holder]] (in the case of [[drip coffee]] preparation also called a dripper) or coffee maker, the filter needs to be a specific shape and size.

== Disposable paper filters ==
{{anchor|Disposable filter|Paper|Sibarist|Cafec}}
{{Main|Filter paper}}

=== History of paper filters===
{{anchor|Blotting paper}}In 1782<!-- or 1784? -->, [[Johann Georg Krünitz]] described a then-new method to extract coffee utilizing [[blotting paper]] in a (tinned) metal filter cone shape like.<ref name="Krünitz_1784"/><ref name="Bramah_1995"/><ref name="Beutelspacher_2006"/>{{rp|pages=139–140}}<ref name="jam_2008"/>

{{anchor|Hamburg filter}}In Germany and the Netherlands, filter paper inserts were used in narrow conical metal filter holders called "{{lang|de|Hamburger Spitztrichter}}" (Hamburg filter) to extract drip coffee.<ref name="Holzborn_1928"/>{{rp|page=977}}<ref name="Bramah_1995"/>{{rp|pages=77ff.}}<ref name="Beutelspacher_2006"/>{{rp|page=139}} In 1785, a silver filter was manufactured by Johann Christopher Hellmers, suggesting that porcelain versions existed even earlier.<ref name="Bersten_1993"/>{{rp|pages=63–64}} Hamburg filters made out of (enameled) metal or porcelain were still very common in the early 1900s in Germany.<ref name="Bersten_1993"/>{{rp|pages=162–163}}

In 1847, {{ill|Elard Römershausen<!-- his actual name-->|d|Q60840525}}<!-- 1784-1857) --> (aka Elard Romershausen<!-- spelling used in some of his publications --> and Elard [von] Rommershausen<!-- spelling used in some third party publications about him -->) experimented with paper filters while constructing an early "air press coffee machine".<ref name="Beutelspacher_2006"/>{{rp|pages=137, 139}}

In 1885, Heinrich Böhnke-Reich (aka Boehnke-Reich) [[food contact materials|warned]] of using old [[wall paper]] as coffee filters,<ref group="nb" name="NB_Health"/> but favorably described sheets of thick wool-style greyish paper which could be cut into shape for use as quick filters in a conical filter holder.<ref name="Böhnke-Reich_1885"/>{{rp|pages=107–120}}<ref name="Bersten_1993"/>{{rp|page=162}}

{{anchor|Wilda}}In 1894, the Wilda'sche coffee filter device by Eugen Wilda used single-use cloth filter bags, which, in the corresponding patent, were considered to be superior to paper filter bags presumably already in use at the time.<ref name="Bersten_1993"/>{{rp|page=163}}<ref name="Beutelspacher_2006"/>{{rp|page=139}}

On 8 July 1908, the first commercial paper coffee filter was a 94 mm round filter disk devised by the German entrepreneur [[Melitta Bentz]].<ref name="Beutelspacher_2006"/>{{rp|pages=140–}}<ref name="Hempe_2008"/> She wanted to remove the bitter taste caused by [[overbrewing]].<ref name="Hempe_2008"/><ref name="Bellis_2017"/> She [[patented]] her invention and formed a company, [[Melitta]], to sell the coffee filters (in a format and size later<!-- when exactly? --> named "[[#Melitta 1|1]]"<ref group="nb" name="NB_Melitta-confusion"/>), hiring her husband and two sons to assist her as the first employees.<ref name="Beutelspacher_2006"/><ref name="DPMA_2023"/>

=== Filter shapes and sizes ===
==== Cone-, fan- or boat-shaped filters ====
===== Melitta filter systems and derivatives =====
{{anchor|Blitz|Brasil|Melitta|100|101|102|103}}
[[File:Gele koffiepot “VAN NELLE” en filter “Melitta”, objectnr 60412-1-2.A-B(2).JPG|thumb|1960s glazed ceramic filter holder made by [[Melitta]]]]
Since 1930<ref name="Kampmann_2018"/>/1931<!-- other sources state 1931 -->, there was a conical paper coffee filter named "{{lang|de|Blitz-Filter}}" (English: flash filter) featuring rims manufactured by the Berlin-based<ref name="Hempe_2008"/>{{rp|pages=33–34, 36}} {{lang|de|Blitz-Filter GmbH}},<ref name="Kampmann_2024"/> a filter paper manufacturer, holding a [[D.R.G.M.]] utility patent<ref name="Kampmann_2024"/> on their filter.<!-- TBD: by O. Schulz filed in 1930??? --><ref name="Kampmann_2018"/> In 1931, Paul Ciupka proposed conical paper coffee filters,<ref name="Ciupka_1931"/>{{rp|page=214}}<ref name="Beutelspacher_2006"/>{{rp|page=141}} which reportedly led to the construction of another coffee filter named "{{lang|de|Brasil Kaffeefilter}}" at the {{ill|Göttinger Aluminiumwerke|de}} (now Alcan) in 1932<!-- in at least 2 sizes: "Gr. 1" and "Gr. 2", whereby Gr. 1 looks almost identical to Melitta 101. -->.<ref name="Bersten_1993"/>{{rp|page=166}}<ref name="Beutelspacher_2006"/>{{rp|page=141}}<ref name="Kampmann_2018"/> It was recommended by the press.<ref name="Eberswalder_1931"/> Melitta bought the rights to the Göttingen D.R.G.M.<!-- Brasil filters are labelled with "D.R.G.M." --> filter patent<ref name="Bersten_1993"/>{{rp|page=166}}<ref name="Beutelspacher_2006"/>{{rp|page=141}}<ref name="Kampmann_2018"/> and, still in 1932,<ref>{{cite web |url=http://schnellfilter.de/index1.htm |archive-url=https://web.archive.org/web/20220313075549/http://schnellfilter.de/index1.htm |archive-date=2022-03-13 |title=Melitta-Schnellfilter}}</ref> introduced their {{lang|de|Schnell-Filter}} (English: quick filter),<ref name="Beutelspacher_2006"/>{{rp|page=141}}<ref name="Hempe_2008"/>{{rp|pages=33–34, 36}}<ref name="Kampmann_2018"/> a cone-shaped filter holder looking almost identical to the Brasil filter<ref name="Kampmann_2024"/><!-- Melitta filters had finer ribs than Brasil filters --> with a circular bottom with 8 (later 4)<!-- Brasil filters had 4 holes, Melitta filter had 8 or 4 holes --> holes suitable for use with squarish sheets of {{anchor|Negotiator}}filter paper, which still had to be pressed into shape through a metal cone (a so called {{lang|de|Eindrücker}} (presser), a type of filter shaping tool also known as "negotiator" today).<ref name="Beutelspacher_2006"/>{{rp|pages=141–142}}<ref name="Treffer_2016"/> These quick filter holders were manufactured of porcelain or metal, available in sizes named "100", "101", "102", and "103". This system was available up to 1939.<ref>{{cite web |url=http://schnellfilter.de/index5.htm |archive-url=https://web.archive.org/web/20220331041823/http://schnellfilter.de/index5.htm |archive-date=2022-03-31 |title=Melitta-Schnellfilter}}</ref>

{{anchor|Filtertüte|104|105|106|112|123|401|402|801}}
[[File:Koffiefilter RA.jpg|thumb|right|Fan- or boat-shaped coffee filter, made of unbleached paper]]
Patented in 1935,<ref name="Hempe_2008"/> Melitta introduced the {{lang|de|Filtertüte}} (English: filter bag) in various sizes in 1936 or 1937<ref name="Beutelspacher_2006"/>{{rp|page=141}}<ref name="Hempe_2008"/><!-- other sources state 1936 or even 1938 https://www.sampor.de/index.php?id=4977 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm --><ref name="Melitta_1"/> In Germany, Melitta holds a trademark on the term "{{lang|de|Filtertüte}}" (English: filter bag) for the conical fan- or boat-shaped paper filter introduced in <!-- or 1936 -->1937,<ref name="MDR_2020">{{Cite web |date=2022-12-15 |title=Melitta Bentz und die Geschichte des Kaffeefilters {{!}} MDR.DE |url=https://www.mdr.de/geschichte/mitteldeutschland/orte/dresden/kaffeefilter-melitta-bentz-dresden-erfindung-100.html |access-date=2024-10-28 |archive-url=https://web.archive.org/web/20221215085051/https://www.mdr.de/geschichte/mitteldeutschland/orte/dresden/kaffeefilter-melitta-bentz-dresden-erfindung-100.html |archive-date=2022-12-15}}</ref> that is why other manufacturers use terms like coffee filter, paper filter, etc.

In 1936,<ref name="Kampmann_2024"/> Melitta also took over the manufacturer of the "{{lang|de|Blitz-Filter}}".<ref name="Hempe_2008"/>{{rp|pages=33–34, 36}} The cone-shaped filter holders were refined in 1936 to get a slot-shaped bottom (originally with 4 holes) more suitable for the filter bags, now looking more fan- or boat-shaped.<ref name="Hempe_2008"/> Over the years the system was expanded to eventually consist of filter bag sizes "100" (for 1–2 cups à {{frac|1|6}}<ref name="Melitta_7Winke"/>–{{frac|1|8}} litre{{clarify|date=March 2023}}<ref name="Melitta-Schnellfilter-DRP_191x">{{Cite web |date=2023-02-26 |title=Tag des Kaffees, Mein Sammlerportal, Kaffee, Berlin, alte Reklame auf sampor.de / MSP |url=https://www.sampor.de/index.php?id=2328 |access-date=2024-03-01 |archive-url=https://web.archive.org/web/20230226143822/https://www.sampor.de/index.php?id=2328 |archive-date=2023-02-26}}</ref><ref name="Melitta-Schnellfilter">{{Cite web |date=2023-02-26 |title=Kaffeefilter Original Melitta 102 in Frankfurt am Main – Bockenheim {{!}} eBay Kleinanzeigen |url=https://www.ebay-kleinanzeigen.de/s-anzeige/kaffeefilter-original-melitta-102/2302199422-86-4322 |access-date=2024-03-01 |archive-url=https://web.archive.org/web/20230226161249/https://www.ebay-kleinanzeigen.de/s-anzeige/kaffeefilter-original-melitta-102/2302199422-86-4322 |archive-date=2023-02-26}}</ref><ref name="Melitta_7Winke"/>), "101"<!-- One source states: 95 mm https://web.archive.org/web/20230327082859/https://www.lofbergs.se/fragor-och-svar/faq/vad-betyder-kaffefilterbeteckningarna-102-och-1x4/ --> (for 2–3<ref name="Melitta-Schnellfilter-DRP_191x"/> or 2–4 cups<!-- à 1/6 litre --><ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/><ref>{{cite web |url=http://www.melitta.de/de/Melitta-Kaffeefilter-Porzellan-101-849.html |archive-url=https://web.archive.org/web/20160424144845/http://www.melitta.de/de/Melitta-Kaffeefilter-Porzellan-101-849.html |archive-date=2016-04-24 |title=Melitta – Produktwelt – Melitta Kaffeefilter Porzellan 101}}</ref>), "102"<!-- measured bottom width on Melitta filter bag ca. 48 mm, edge length ca. 109 mm, angle ca. 57°. Other sources state: 115 mm https://web.archive.org/web/20230327082859/https://www.lofbergs.se/fragor-och-svar/faq/vad-betyder-kaffefilterbeteckningarna-102-och-1x4/ --> (for 3–6,<ref name="Melitta-Schnellfilter-DRP_191x"/> 4–6<ref>{{cite web |url=http://www.melitta.de/de/Melitta-Kaffeefilter-Porzellan-102-848.html |archive-url=https://web.archive.org/web/20161016193302/http://www.melitta.de/de/Melitta-Kaffeefilter-Porzellan-102-848.html |archive-date=2016-10-16 |title=Melitta – Produktwelt – Melitta Kaffeefilter Porzellan 102}}</ref> or 4–8 cups<!-- à 1/6 litre --><ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/>), "103" (for 6–15,<ref name="Melitta-Schnellfilter-DRP_191x"/> 8–15 cups<!-- à 1/6 litre --><ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/><ref>{{Cite web |title=kaffeefilter_melitta_13b |url=https://www.sampor.de/assets/images/getraenke-und-co/filter/kaffeefilter_melitta_13b.jpg |archive-url=https://web.archive.org/web/20230226144946/https://www.sampor.de/assets/images/getraenke-und-co/filter/kaffeefilter_melitta_13b.jpg |archive-date=2023-02-26}}</ref> or 10–15<ref>{{cite web |url=https://www.ebay-kleinanzeigen.de/s-anzeige/melitta-schnellfilter-103-dreiloch-10-15-tassen/2352923538-240-9364 |archive-url=https://web.archive.org/web/20230301235938/https://www.ebay-kleinanzeigen.de/s-anzeige/melitta-schnellfilter-103-dreiloch-10-15-tassen/2352923538-240-9364 |archive-date=2023-03-01 |title=Melitta Schnellfilter 103 Dreiloch 10–15 Tassen}}</ref>), "104" (for 15–25<ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/> or 15–30 cups<ref name="Melitta-Schnellfilter-DRP_191x"/>), "105" (for 25–50<!-- cups à 1/6 litre --><ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/><ref>{{cite web |url=https://www.ebay.de/itm/185219207363 |archive-url=https://web.archive.org/web/20230226150817/https://www.ebay.de/itm/185219207363 |archive-date=2023-02-26 |title=Vintage Melitta Kipp- Warmhaltekanne Typ 905 + Schnellfilter Alu Porzellan 1950 {{pipe}} eBay}}</ref> or 30–60 cups<ref name="Melitta-Schnellfilter-DRP_191x"/>), "106" (for 50–80<ref name="Melitta-Schnellfilter"/><ref name="Melitta_7Winke"/> or 60–100 cups<ref>{{cite web |url=http://huelbach.de/aktion.htm |archive-url=https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm |archive-date=2017-03-16 |title=Interessengemeinschaft "RETTET DEN HUELBACH"}}</ref>), "112" (for 2 cups<!-- à 1/6 litre -->, with pot mount<!-- patented in 1955 and marketed up to the early 1960s --><ref>{{Cite web |title=Gebrauchsanleitung der Melitta - Filter und Kanne 112 |url=https://www.sampor.de/index.php?id=2740 |url-status=dead |archive-url=https://web.archive.org/web/20230328131748/https://www.sampor.de/index.php?id=2740 |archive-date=2023-03-28}}</ref><ref>{{Cite web |title=Und darauf müssen Sie besonders achten |url=https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01a.jpg |url-status=dead |archive-url=https://web.archive.org/web/20230328132310/https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01a.jpg |archive-date=2023-03-28}}</ref><ref>{{Cite web |title=Coffee filter instructions |url=https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01c.jpg |url-status=dead |archive-url=https://web.archive.org/web/20230328132530/https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01c.jpg |archive-date=2023-03-28}}</ref><ref>{{Cite web |title=Gebrauchsanleitung für Filter Kanne |url=https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01.jpg |url-status=dead |archive-url=https://web.archive.org/web/20230328131750/https://www.sampor.de/assets/images/alles-aus-papier/anleitungen/ga_melitta_112_01.jpg |archive-date=2023-03-28}}</ref><ref>{{cite web |url=https://www.etsy.com/de/listing/733225114/melitta-filter-nr-112?show_sold_out_detail=1&ref=nla_listing_details |archive-url=https://web.archive.org/web/20230301213217/https://www.etsy.com/de/listing/733225114/melitta-filter-nr-112?show_sold_out_detail=1&ref=nla_listing_details |archive-date=2023-03-01 |title=Melitta Filter No. 112 – Etsy.de}}</ref><ref>{{cite web |url=https://www.ebay.de/itm/324309709432 |archive-url=https://web.archive.org/web/20230301213107/https://www.ebay.de/itm/324309709432 |archive-date=2023-03-01 |title=Melitta Porzellan Filter Schnellfilter 112 weiß 3-Loch grüne Schrift 50er/ 60erJ}}</ref>) and "123"<!-- introduced in 1964, produced up to 1969/1972 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm --><ref name="Siems_2015"/><!-- shows an ad for size 123 dated 1983 --> (for 6–10 cups<ref>{{cite web |url=https://www.ebay.de/itm/125732180411 |archive-url=https://web.archive.org/web/20230226151312/https://www.ebay.de/itm/125732180411 |archive-date=2023-02-26 |title=Melitta Minden Kaffee Filter 123 2 Loch 50er Kaffeefilter {{pipe}} eBay}}</ref>). The system also included special types like tea filters "401" (1–6 cups,<ref>{{cite web |url=https://www.ebay-kleinanzeigen.de/s-anzeige/-suche-alte-melitta-kaffeefilter-porzellan/2369922157-86-2603 |archive-url=https://web.archive.org/web/20230302213556/https://www.ebay-kleinanzeigen.de/s-anzeige/-suche-alte-melitta-kaffeefilter-porzellan/2369922157-86-2603 |archive-date=2023-03-02 |title=SUCHE alte Melitta Kaffeefilter Porzellan}}</ref> compatible with "101"<ref name="Siems_2015"/><ref name="Melitta_7Winke">{{cite web |url=https://www.ebay-kleinanzeigen.de/s-anzeige/original-melitta-kaffee-schnellfilter-100-und-401/2276904768-86-9500 |archive-url=https://web.archive.org/web/20230302001643/https://www.ebay-kleinanzeigen.de/s-anzeige/original-melitta-kaffee-schnellfilter-100-und-401/2276904768-86-9500 |archive-date=2023-03-02 |title=Original Melitta Kaffee-Schnellfilter 100 und 401}}</ref>) and "402"<!-- introduced in 1932 according to Hempe --> (for 3–9 cups,<ref>{{cite web |url=https://www.ebay-kleinanzeigen.de/s-anzeige/melitta-teefilter-402-mit-bruehstab/2352919705-240-9364 |archive-url=https://web.archive.org/web/20230301235301/https://www.ebay-kleinanzeigen.de/s-anzeige/melitta-teefilter-402-mit-bruehstab/2352919705-240-9364 |archive-date=2023-03-01 |title=Melitta Teefilter 402 mit Brühstab}}</ref> compatible with "102"<ref>{{Cite web |date=2023-03-28 |title=Tag des Kaffees, Mein Sammlerportal, Kaffee, Berlin, alte Reklame auf sampor.de / MSP |url=https://www.sampor.de/index.php?id=4039 |access-date=2024-10-28 |archive-url=https://web.archive.org/web/20230328131348/https://www.sampor.de/index.php?id=4039 |archive-date=2023-03-28}}</ref>) and the miniature filter "801"<!-- originally introduced in 1964, replicated in --> (for 1–2 or 1–3<ref name="R801">{{cite web |url=https://www.ebay-kleinanzeigen.de/s-anzeige/original-melitta-puppenkaffee-801-sammlerstuecke/2274090624-234-6939 |archive-url=https://web.archive.org/web/20230402224943/https://www.ebay-kleinanzeigen.de/s-anzeige/original-melitta-puppenkaffee-801-sammlerstuecke/2274090624-234-6939 |archive-date=2023-04-02 |title=Original Melitta Puppenkaffee 801 Sammlerstücke}}</ref> small cups for children, or 1 normal cup<ref name="R801"/>). {{anchor|502}}Brigitta<!-- Brigitta is a trademark of Melitta at least in South America in 2024: https://www.melitta-group.com/de/unternehmen/ueber-uns/melitta-group/melitta-south-america#accordion-cad0a3b79b-item-0d8de9dbe0--> once<!-- when exactly? --> marketed a fan- or boat-shaped filter size "502"<!-- (for ?–? cups) reportedly similar to 1×4. It was also sold in Germany in conjunction with a 1.1 litre coffee pot https://www.kleinanzeigen.de/s-anzeige/karaffe-brigitta-glaskanne-1-1l-filter-kaffee-tee/2785703317-248-805 -->.<ref>{{cite web |title=Kaffeefilter aus Kunststoff – Größe 502 – Bisher Unbenutzt |url=https://www.ebay-kleinanzeigen.de/s-anzeige/kaffeefilter-aus-kunststoff-von-melitta-groesse-502-unbenutzt/2372290262-86-1762 |access-date=2023-04-13 |url-status=dead |archive-url=https://web.archive.org/web/20230412153240/https://www.ebay-kleinanzeigen.de/s-anzeige/kaffeefilter-aus-kunststoff-von-melitta-groesse-502-unbenutzt/2372290262-86-1762 |archive-date=2023-04-12}}</ref><ref>{{cite web |url=https://www.youpickit.de/Produkt/Brigitta-Filtert%C3%BCten-Gr-502-Pack-80/131247 |archive-url=https://web.archive.org/web/20230301201500/https://www.youpickit.de/Produkt/Brigitta-Filtert%C3%BCten-Gr-502-Pack-80/131247 |archive-date=2023-03-01 |title=Brigitta Filtertüten Gr. 502 Pack 80 [4006508124473] – Angebote – YouPickIt}}</ref> A disadvantage of the system was that one had to pour water continuously or several times while the proper amount of necessary water could only be guessed.

{{anchor|1x2|1x4|1x6|1x10}}Therefore, in 1963<ref name="Hempe_2008"/> or 1965<ref name="Melitta_1">{{Cite web |title=Jahre Melitta Zeitstrahl Allgemein |url=https://www.melitta-group.com/datei.php?src=download/111-Jahre-Melitta_Zeitstrahl-Allgemein.pdf |archive-url=https://web.archive.org/web/20230310205124/https://www.melitta-group.com/datei.php?src=download/111-Jahre-Melitta_Zeitstrahl-Allgemein.pdf |archive-date=2023-03-10 |website=www.melitta-group.com}}</ref> Melitta developed a new fan- or boat-shaped filter system with corresponding "1×" nomenclature: In this system the filters are sized big enough so that the whole amount of water (except for the water needed for [[coffee blooming|blooming]]) can be poured in one go. Consequently, the filter sizes "1×2",<!-- Introduced 1969 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm. Measured edge length ca. 93 mm. Other source states: 100 mm https://web.archive.org/web/20230327082859/https://www.lofbergs.se/fragor-och-svar/faq/vad-betyder-kaffefilterbeteckningarna-102-och-1x4/ --> "1×4",<!-- Introduced 1966 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm. Measured edge length ca. 118-120 mm, delta 25 mm. Other source states: 125 mm https://web.archive.org/web/20230327082859/https://www.lofbergs.se/fragor-och-svar/faq/vad-betyder-kaffefilterbeteckningarna-102-och-1x4/ --> "1×6"<!-- Introduced 1965 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm. Measured edge length ca. 143 mm, delta 25 mm. Other source states: 150 mm https://web.archive.org/web/20230327082859/https://www.lofbergs.se/fragor-och-svar/faq/vad-betyder-kaffefilterbeteckningarna-102-och-1x4/ --> and "1×10"<!-- Introduced 1966 https://web.archive.org/web/20170316133856/http://huelbach.de/aktion.htm. --><!-- Note: I have never seen "1x12", but the following source states that "1x12" existed as well --><ref>{{cite web |title=Objekt #1 |date=2014-05-23 |language=de |publisher=Museum Bügeleisenhaus Heimatverein Hattingen/Ruhr |location=Hattingen, Germany |url=https://buegeleisenhaushattingen.wordpress.com/besuchen/das-konzept-fuer-das-museum-im-buegeleisenhaus/ausstellungsarchiv/ausstellungen-2014/hattingerschaetze-de/objekt-1/ |access-date=2023-02-25 |url-status=live |archive-url=https://web.archive.org/web/20230225192500/https://buegeleisenhaushattingen.wordpress.com/besuchen/das-konzept-fuer-das-museum-im-buegeleisenhaus/ausstellungsarchiv/ausstellungen-2014/hattingerschaetze-de/objekt-1/ |archive-date=2023-02-25}}</ref> result in 2, 4,<ref>{{Cite web |date=2016-10-16 |title=Melitta – Produktwelt – Melitta® Kaffeefilter Porzellan 1x4® |url=http://www.melitta.de:80/de/Melitta-Kaffeefilter-Porzellan-1x4-850.html |access-date=2024-10-28 |archive-url=https://web.archive.org/web/20161016194258/http://www.melitta.de:80/de/Melitta-Kaffeefilter-Porzellan-1x4-850.html |archive-date=2016-10-16}}</ref> 6, and 10 cups of coffee when filling the filter once. Since these filters only differ in height and have otherwise the exact same geometry, bottom width (about <!-- measured -->49&nbsp;mm<!-- 48–50 mm -->) and angle (about <!-- measured -->54°<!-- 53°–55° -->), the filter bags are interchangeable between filter holders of different sizes.

Both systems are still in use today in principle, but the sizes "103", "104", "105", "106", "112", "123", "401", "402", ("502",) "801" and "1×10" are no longer manufactured.

{{anchor|0|1|2|4|6}}Common in the US are fan- or boat-shaped filters "#0" (similar to "100"), "#1" (similar to "101"),<ref group="nb" name="NB_Melitta-confusion"/> "#2" (similar to "102"),<ref group="nb" name="NB_Melitta-fan"/> "#4" (similar to "1×4"),<ref group="nb" name="NB_Melitta-4"/> and "#6" (similar to "1×6"),<ref group="nb" name="NB_Melitta-6"/><ref group="nb" name="NB_Melitta-tm"/> with "#2", "#4" and "#6" being particularly popular, as well as basket-shaped filters in an 8–12 cup home size and larger restaurant sizes.

===== Hario filter system =====
[[File:Hario V60 dripper (30519007832).jpg|thumb|A Hario V60 permanent filter holder placed on a mug.]]
{{anchor|V60|W60|Switch|Hario 01|Hario 02|Hario 03}}

The {{ill|Hario|ja|HARIO}} "vector 60" V60 is a cone-shaped brewer (with 60° angle), with ribs along the wall (to prevent the paper sticking and allowing air through) and a single large hole (to allow water to pass through unrestricted).<ref name="hario">{{cite web |title=V60 – HARIO CO., LTD. |url=https://global.hario.com/sp_v60series.html |access-date=2022-08-27 |website=global.hario.com}}</ref>
Hario began designing brewers in 1980; the V60 design was released in 2004.<ref name=hario/><ref name="Kumstova_2018">{{cite web |author-last=Kumstova |author-first=Karolina |date=2018-05-16 |title=The Story and Development of Hario V60 |url=https://europeancoffeetrip.com/hario-v60/ |access-date=2022-08-27 |website=European Coffee Trip |language=en-GB |url-status=live |archive-url=https://web.archive.org/web/20230327090744/https://europeancoffeetrip.com/hario-v60/ |archive-date=2023-03-27}}</ref>
The brewer received the [[Good Design Award (Japan)|Japanese Good Design Award]] in 2007<ref>{{cite web |title=dripper V60series [VD-01, VD-02, VD-03, VDC-01, VDC-02] |url=http://www.g-mark.org/award/describe/33271?locale=en |access-date=2022-08-27 |website=Good Design Award}}</ref>
and is used by many of the winners in the [[World Brewers Cup]]. {{anchor|Flat}}In partnership with 2013 [[World Barista Championship|World Barista Champion]] Pete Licata it was further developed into the Hario W60, a brewer with a flat-bottomed mesh filter, to "address the concern baristas have with 'flat bed' brewing".<ref>{{cite web |author-last=Cadwalader |author-first=Zac |title=Hario Just Launched A Brand New Brewer, The W60 Dripper |url=https://sprudge.com/hario-just-launched-a-brand-new-brewer-the-w60-dripper-177448.html |access-date=2022-08-27 |website=Sprudge |date=2021-04-23 |language=en-US}}</ref>
The Hario Switch combines [[coffee steeping|steeping]] with drip filtering.

Hario has cone-shaped paper filter bag sizes "01" (for 1 cup<!-- introduced when? -->), "02" (for 1–4 cups<!-- introduced when? -->) and "03" (for 1–6 cups<!-- introduced when? -->).<ref>{{cite web |title=V60 - HARIO CO., LTD. |url=https://global.hario.com/sp_v60series.html |access-date=2022-08-27 |website=global.hario.com |url-status=live |archive-url=https://web.archive.org/web/20230306120552/https://global.hario.com/v60/v60series.html |archive-date=2023-03-06}}</ref><ref name="Kumstova_2018"/>

==== Other filter shapes ====
{{anchor|Pyramid filter|Disk filter|Ring filter|Basket filter|Roll filter|Wrap filter|202s|203|206|220|240|270|Melitta 1|Melitta 1a|Melitta 2|Melitta 2b|3.5in|164mm|190mm|203mm|235mm|240mm|244mm|256mm|260mm|290mm|330mm|400mm|440mm|250/90|250/110|2004|Kalita Wave}}
[[File:Coffee-filter.jpg|thumb|A basket-type coffee filter, here made of bleached paper]]
{{anchor|SAI|<!-- Phoenix 70-->P70|C70|<!-- Page Brewer -->G70|F70}}Saint Anthony Industries (SAI) introduced a conical filter called "C70" (2018) and a flat-bottom filter "F70" (2019) with a steep 70° angle.

Other Melitta filter sizes include the pyramid filters "202s", "203", "206(G)", "220(G)", "240(G)" and "270(G)"<!-- 270/270G -->, round filter disks "1" (94&nbsp;mm), "1a" (60&nbsp;mm), "2" (120&nbsp;mm) and "2b", and "50"<!-- for coffeemaker model 50 (1925?) -->,<ref name="Melitta_1"/><ref>{{Cite web |title=SP_Melitta_0051_20x20cm_300dpi (download) |url=https://www.melitta-group.com/datei.php?src=download/SP_Melitta_0051_20x20cm_300dpi.jpg |website=www.melitta-group.com}}</ref> circle filter rings (for [[percolator]]s) "3&nbsp;{{frac|1|2}}&nbsp;in." (89&nbsp;mm),<ref>{{cite web |url=https://www.kleinanzeigen.de/s-anzeige/melitta-rundfilter-in-der-geschlossenen-originalverpackung-149-/2428035048-240-2777 |archive-url=https://web.archive.org/web/20230507143808/https://www.kleinanzeigen.de/s-anzeige/melitta-rundfilter-in-der-geschlossenen-originalverpackung-149-/2428035048-240-2777 |archive-date=2023-05-07 |title=Melitta Rundfilter in der geschlossenen Originalverpackung (149)}}</ref> "164mm", "190mm"<!-- for container DE 5 https://web.archive.org/web/20240105023027/https://animo.eu/de-de/produkte/zubehor/filterpapier/rundfilterpapier -->, "203mm", "235mm", "240mm", "244mm", "256mm", "260mm"<!-- for container CE/CI 4, 6, 8, 10, DE 10 https://web.archive.org/web/20240105023027/https://animo.eu/de-de/produkte/zubehor/filterpapier/rundfilterpapier -->, "290mm", "330mm"<!-- for container CE/CI 12, 16, 20, 25, DE 20 https://web.archive.org/web/20240105023027/https://animo.eu/de-de/produkte/zubehor/filterpapier/rundfilterpapier -->, "400mm" and "440mm"<!-- for container DE 40 https://web.archive.org/web/20240105023027/https://animo.eu/de-de/produkte/zubehor/filterpapier/rundfilterpapier -->, [[pleat|prepleated]] flat-bottom basket filters "(A)250/90" (250&nbsp;mm<!-- top diameter -->/90&nbsp;mm<!-- bottom diameter -->, also known as "90/250"<!-- by Animo -->) and "(A)250/110" (250&nbsp;mm<!-- top diameter -->/110&nbsp;mm<!-- bottom diameter -->), roll filters "2004" as well as wrap filters (for percolators, 232&nbsp;× 241&nbsp;mm<!-- 9-1/8" × 9-1/2" -->).<ref>{{Cite web |title=1300_1300_90/584-008 |url=https://www.esmeyer-shop.de/out/pictures/generated/product/1/1300_1300_90/584-008.jpg |archive-url=https://web.archive.org/web/20230226102504/https://www.esmeyer-shop.de/out/pictures/generated/product/1/1300_1300_90/584-008.jpg |archive-date=2023-02-26}}</ref><ref>{{cite web |url=https://www.rapid.nl/catalog/index.php?view=all&manufacturers_id=11 |archive-url=https://web.archive.org/web/20230226113433/https://www.rapid.nl/catalog/index.php?view=all&manufacturers_id=11 |archive-date=2023-02-26 |title=Melitta{{pipe}}Rapid}}</ref> <!-- The former VEB Freiberger Zellstoff und Papierfabrik offered round disc filters in diameters 94 and 120 mm. Probably other sizes as well --> While some of them are still available today, most of them have fallen out of use for long.

{{anchor|602}}A squarish pyramid filter Filtra "602" was available as well.<ref>{{cite web |url=https://kaffeefilter.webfenster.ch/Kaffeefilter%20Exoten/index.html |archive-url=https://web.archive.org/web/20230220200632/https://kaffeefilter.webfenster.ch/Kaffeefilter%20Exoten/index.html |archive-date=2023-02-20 |title=Kaffeefilter Exoten}}</ref>

Other basket filter sizes include "101/317", "152/350", "152/457", "203/533" and "280/635".<!-- https://web.archive.org/web/20240105022845/https://animo.eu/de-de/produkte/zubehor/filterpapier/korbfilterpapier -->

Other round filter disks include 160&nbsp;mm<!-- for Animo 25P, 40P -->, 220&nbsp;mm<!-- for Animo 80P(VW), 100P(VW) -->, 195&nbsp;mm<!-- for Percostar 3, 5, 6 -->, 230&nbsp;mm<!-- for Percostar 12 und 15 --><!-- https://web.archive.org/web/20240105023027/https://animo.eu/de-de/produkte/zubehor/filterpapier/rundfilterpapier -->.

{{anchor|Aeropress|Hoop}}The [[Aeropress]] and Ceado Hoop<!-- 2023 --> use round paper filter disks with a diameter of c. 63&nbsp;mm<!-- some sources say 62 mm and 64 mm for the Aeropress, and 2.5" = 63.5 mm for the Hoop -->.

{{anchor|Tricolate}}The German Tricolate coffee dripper<!-- 2018 --> uses round paper filter disks with a diameter of 88&nbsp;mm.

{{anchor|NextLevel|LVL-10|Pulsar}}The Kanas-based NextLevel drippers<!-- 2021 --> use proprietary round disk paper filters as well (95&nbsp;mm for the LVL-10 and 77&nbsp;mm for the Pulsar).<ref name="Prince_2023"/>

The Hario cold brew dripper Slow Brew "Shizuku" (WDC-6) and Water Dripper Clear (WDW-6) take 58&nbsp;mm round filter disks.

===== Chemex filter system =====
{{anchor|Chemex|FP-1|FP-2|FP-2N|FS-100|FSU-100|FC-100}}The six conical filter holder sizes for the [[Chemex]] coffee maker (originally introduced in 1941) and the [[Funnex]] utilize two different sizes of paper filters. A half-moon shaped filter paper (bleached: FP-2, unbleached: FP-2N) is used for the 3-cup<!-- à 150 ml or 5 oz  --> holders (CM-1<!-- handblown -->, CM-1C<!-- classic -->, CM-1GH<!-- glass handle -->) and the Funnex (CM-FNX), which must be folded before use. The larger holders for 5 (CM-2<!-- handblown -->), 6 (CM-6A<!-- classic -->, CM-6GH<!-- glass handle -->), 8 (CM-3<!-- handblown -->, CM-8A<!-- classic -->, CM-8GH<!-- glass handle -->), 10 (CM-10A<!-- classic -->, CM-10GH<!-- glass handle -->) and 13 cups (CM-4<!-- handblown -->) can alternatively use prefolded square sheets (bleached: FS-100, unbleached: FSU-100), prefolded circle filters (bleached: FC-100) or unfolded circle filters (bleached: FP-1). The paper is 20–30% thicker than regular paper filters.

=== Other filter parameters and properties ===
Other important coffee filter paper parameters are strength, compatibility, efficiency and capacity.

If a coffee filter is not ''strong'' enough, it will tear or rupture, allowing coffee grains through to the coffee pot. ''Compatibility'' describes a filter medium's resistance to degradation by heat and chemical attack; a filter that is not compatible with the liquid passing through it is likely to break down, losing strength ([[structural failure]]). ''Efficiency'' is the retention of particles in a target (size) category. The efficiency is dictated by the particles or substances to be removed. A large-mesh filter may be efficient at retaining large particles but inefficient at retaining small particles. ''Capacity'' is the ability to "hold" previously removed particles while allowing further flow. A very efficient filter may show poor capacity, causing increased resistance to flow or other problems as it plugging up prematurely and increasing resistance or flow problems. A balance between particle capture and flow requirements must be met while ensuring integrity.

== Reusable cloth filters ==
{{anchor|Reusable filter|Cloth}}
[[File:Filtre-pour-une-tasse-cafe.jpg|thumb|[[Flannel]] filter placed on a metal support in 1868.]]
Reusable cloth (such as [[cotton]],<ref name="Böhnke-Reich_1885"/><ref name="Bersten_1993"/>{{rp|pages=62, 162}} [[hemp]],<ref name="Jöcher_1825"/><ref name="Böhnke-Reich_1885"/><ref name="Ciupka_1949"/>{{rp|page=47}}<ref name="Bersten_1993"/>{{rp|page=162}} [[linen]],<ref name="Krünitz_1784"/><ref name="Jöcher_1825"/><ref name="Ciupka_1949"/>{{rp|page=47}}<ref name="Bersten_1993"/>{{rp|page=64}} [[silk]],<ref name="Jöcher_1825"/><ref name="Ciupka_1949"/>{{rp|page=47}}<ref name="Bersten_1993"/>{{rp|page=64}} [[wool]],<ref name="Jöcher_1825"/><ref name="Ciupka_1949"/>{{rp|page=47}}<ref name="Bersten_1993"/>{{rp|page=64}} [[hair cloth]],<ref name="Krünitz_1784"/><ref name="Bersten_1993"/>{{rp|page=64}} [[horse hair]],<ref name="Jöcher_1825"/><ref name="Ciupka_1949"/>{{rp|page=47}}<ref name="Bersten_1993"/>{{rp|page=64}} [[fustian]]<!-- Barchent -->, [[muslin]]<ref name="Bersten_1993"/>{{rp|page=62}} or [[flannel]]<ref name="Bersten_1993"/>{{rp|page=62}}) has been used to filter coffee for a very long time.<ref name="Krünitz_1784"/><ref name="Brockhaus_1837"/><ref name="Pierer_1865"/> Like paper, it strains out the coffee grounds, but the cloth filter allows more of the oil to come through than paper filters.<ref name="Hoffmann_2018"/> An example of a cloth filter is the {{lang|es|bolsita}} in Costa Rican [[chorreador]] coffee makers.

== Permanent filters ==
{{anchor|Permanent filter}}
[[File:Vietnamese coffee gear.jpg|thumb|Vietnamese Phin metal filter]]
[[File:Disassembled South Indian coffee filter.jpg|thumb|Indian permanent metal filter]]
Permanent filters can be divided into two groups:

The first type integrates the filter sieve with the holding mechanism into one part.

The second type of permanent filters are inserts to be used with a separate filter holder. For this, they are resembling the shape of disposable paper or reusable cloth filters otherwise used with those filter holders. Like them they can exhibit some amount of water bypass.

Permanent metal filters are also used to prepare filtered coffee, including [[Vietnamese iced coffee]] and [[Indian filter coffee]]. The "[[French press]]" (also referred to as cafetière) uses a metal filter. Other types of permanent filters are made of plastic, porous ceramics, or porcelain (like the double-layered cross-slitted strainer made from through-glazed porcelain of [[Karlsbad-style coffee maker]]s or the special porcelain filter sieves of [[Büttner system]] coffee makers).<ref group="nb" name="NB_Health"/>

== Filter holders ==
Filter holders are made out of plastic (including [[Makrolon]]/[[Exolon (plastic)|Exolon]], [[Tritan (plastic)|Tritan]], [[Ecozen]]), metal (stainless steel, copper, aluminium, emaille), ceramics, porcelain or glass, or, rarely, wood.<!-- https://web.archive.org/web/20231001131040/https://canadiano.co/collections/pour-overs/products/rough-batch-pour-over-coffee-maker --><ref group="nb" name="NB_Health"/> Most of them are designed to be used with disposable paper and reusable cloth filter inserts, but there is also an after-market of permanent filter inserts made out of plastic, metal or ceramics which can be used in filter holders originally designed for paper or cloth filters.<ref group="nb" name="NB_Health"/> Another type of permanent filters combines the actual filter sieve with its holding mechanism into one integral part.

{{anchor|Bypass|Clogging|Channeling}}Filter holders for cone-, fan- or boat- as well as for flat-bottom shaped (paper) filters can be distinguished by features of their mechanical construction, some of which also have a significant influence on taste, brewing time, utility and how (easy) to clean the filter holder:

* filter geometry (Melitta-, Hario-, SAI- or Orea-<!-- 2023 -->style filter shape and angle, etc.)
* filter size (depending on filter geometry and system for a different number of cups and/or different pouring styles)
* rib structure (straight (Melitta, Hario), interrupted ({{ill|Seltmann Weiden|de}}<!-- 102, Lukullus #4 (5095)/#6 (5096), Barista --> or Beem<!-- Pour Over -->), or [[origami]] design<!-- with 20 rips like Origami, KPM -->), direction (straight down (Melitta), spiral (Hario, Seltmann Weiden<!-- Lukullus and Barista -->, Beem<!-- Pour Over -->)), spacing (narrow, sparse<!-- Ritzenhoff & Breker Rio, Tchibo -->) and location (whole inner surface of filter cone, only at lower half of filter cone) to influence bypass and clogging
* {{anchor|Apex}}bottom structure (with or without ridges, conical, apex<!-- 2023+ Orea V4 https://web.archive.org/web/20240323154003/https://shop.orea.uk/products/orea-brewer-v4-ships-jan-24 --> or flat) to influence channeling and clogging
* number of draining holes (1, 2, 3, 4, 5, 8, 10 or 12) and diameter (one large hole as for Hario-, one or more equally-sized small holes as for Melitta-style filters, combination of a large center hole with <!--4-->small surrounding holes as for the Torch Mountain dripper, or an adjustable count of holes<!-- 0, 4, 8 or 12 --> as with the ''December'' dripper)
* material (porcelain, ceramics, stainless steel, copper, aluminium, glass, plastic)<ref group="nb" name="NB_Health"/> and color
* mount (standard plate mount for pots or cups, affixable pot mount (like [[Melitta 112]]), ring mount for a coffee stand or tripod, long cylinder outlet to fit [[Thermos bottle]]s (like Fröfilt ''K''<!-- actually: ""Fröfilt" K." -->, Alfi ''Aroma Plus'', or Gefu ''Sandro'' / Cilio #4<!-- not the other sizes --> filters, or the Friesland filter adapter), single-cup filter mount, or integrated with coffee pot (like with Melitta ''Diabolo''<ref name="Treffer_2016"/>))
* type of handle (none, style of handle, number of grips)
* special features like stopper [[valve]]s (as for [[Melitta 401]]/[[Melitta 402|402]] tea filter holders<!-- 1930s -->, the Clever Dripper<!-- 2009 -->, the Bonavita Immersion Dripper<!-- 2014 -->, the Goat Story GINA<!-- 2016 -->, the December Dripper<!-- 2017 -->, the [[Hario Switch]]<!-- 2019 -->, the Melitta Amano<!-- 2020 -->, the NextLevel Pulsar<!-- 2021 -->, or the Sworksdesign Bottomless Dripper<!-- 2023 -->) for [[steep & release]] brewing, cup-viewing windows (as for Zero Japan Bee House filters<!-- TBD at least since 2006? -->,<ref>{{Cite web |last=Bobak |first=Julia |date=2019-09-24 |title=Bee House Coffee Dripper Review: Good for Newbies |url=https://www.homegrounds.co/beehouse-coffee-maker-review/ |access-date=2024-10-28 |website=Home Grounds |language=en-US}}</ref> Melitta filter holders<!-- porcelain and plastics in 102 and 1×4 --> since 2018<!-- produced in China, not the older ones produced in Germany by Friesland for Melitta up to 2018, but patented much earlier: https://web.archive.org/web/20230609091014/https://www.schlossmuseum.de/sammlungen/melitta-friesland-keramik-aus-varel-rahling-1954-2007/ -->, or the [[Le Crueset]] dripper), anti-[[dribbling (coffeepot)|dribbling]] "tripod" plate design, design for simultaneous pouring into one or two cups (as for Melitta filter holders<!-- porcelain and plastics in 102 and 1×4, also Melitta Amano --> since 2018<!-- produced in China, not the older ones produced in Germany by Friesland for Melitta up to 2018 -->), double-walled design for better [[thermal insulation]] (as for [[Melitta Oslo]] Form 23<!-- 23-100 is the pot --> "102 M" filters<!-- 1964-1972 https://web.archive.org/web/20240427193955/https://www.kleinanzeigen.de/s-anzeige/melitta-oslo-kaffeekanne-kaffeefilter-vintage/2696993041-86-8070 -->,<ref>{{Cite web |title=Oslo - Form 23 - Friesland Porzellan ...hol ich mir nach Hause! |url=https://friesland-porzellan.de/oslo-form-23 |access-date=2024-10-28 |website=friesland-porzellan.de}}</ref> [[KPM Berlin|KPM]] Café Berlin LAB filters #2/#4<!-- designed by Thomas Wenzel, since 2015 -->,<ref>{{Cite web |date=2015-10-17 |title=KPM: Café Berlin |url=https://stilundmarkt.de/Fuers-Sortiment/In-der-Kueche/KPM-Cafe-Berlin |access-date=2024-10-28 |website=stil & markt |language=de}}</ref><ref>{{Cite web |title=KPM KAFFEEFILTER |url=https://www.weitz-porzellan.de/media/2b/5c/58/1654191835/100108167_47_RZ_KPMFilter_Anleitung_A4_12.pdf |access-date=2024-11-01 |website=www.weitz-porzellan.de |language=de}}</ref> the Seltmann Weiden No Limits Barista filter #2<!-- 2013 -->,<ref>{{Cite web|url=https://hotel.seltmann.com/barista-filter-2-m5324-00003-no-limits.html?___store=hotel_de&___from_store=hotel_en%3C!--+--%3E|title=Barista-Filter 2 M5324 00003 No Limits &#124; SELTMANN WEIDEN|website=hotel.seltmann.com}}</ref><ref>{{Cite web |date=2017 |title=IDEEN FÜR IHRE PROMOTION |url=https://www.topp-and-more.de/kataloge/kueche/katalog-kueche-seltmann-promotion-2017.pdf |access-date=2024-11-01 |website=www.topp-and-more.de |language=de}}</ref> the Melitta 111th Anniversary Set filter 102<!-- MPN 6769089, 2019, similar to classical Melitta Oslo Form 23 -->,<ref>{{Cite web |url=https://www.kleinanzeigen.de/s-anzeige/melitta-jubilaeums-set-102-kaffeefilter-aus-porzellan/2406480643-86-1214%3C!--+https://web.archive.org/web/20230521101412/https://www.kleinanzeigen.de/s-anzeige/melitta-jubilaeums-set-102-kaffeefilter-aus-porzellan/2406480643-86-1214+--%3E |archive-url=https://www.kleinanzeigen.de/s-anzeige/melitta-jubilaeums-set-102-kaffeefilter-aus-porzellan/2406480643-86-1214%3C!--+https://web.archive.org/web/20230521101412/https://www.kleinanzeigen.de/s-anzeige/melitta-jubilaeums-set-102-kaffeefilter-aus-porzellan/2406480643-86-1214+--%3E |url-status=dead |archive-date=2007-06-15 |title=eBay Kleinanzeigen ist jetzt Kleinanzeigen |website=Kleinanzeigen}}</ref><ref>{{Cite web |url=https://www.kleinanzeigen.de/s-anzeige/porzellan-kaffeefilter-kanne-melitta-geschenkset/2416344895-86-9195%3C!--+https://web.archive.org/web/20230521101225/https://www.kleinanzeigen.de/s-anzeige/porzellan-kaffeefilter-kanne-melitta-geschenkset/2416344895-86-9195+--%3E |archive-url=https://www.kleinanzeigen.de/s-anzeige/porzellan-kaffeefilter-kanne-melitta-geschenkset/2416344895-86-9195%3C!--+https://web.archive.org/web/20230521101225/https://www.kleinanzeigen.de/s-anzeige/porzellan-kaffeefilter-kanne-melitta-geschenkset/2416344895-86-9195+--%3E |url-status=dead |archive-date=2007-06-15 |title=eBay Kleinanzeigen ist jetzt Kleinanzeigen |website=Kleinanzeigen}}</ref> the Fellow Stagg X/XF drippers, the [[Chemex Funnex]], the notNeutral Gino dripper<!-- (2016) -->, the [[Villeroy & Boch]] Coffee Passion V60 filter,<ref>{{cite web |url=https://www.villeroy-boch.de/shop/coffee-passion-doppelwandiger-kaffeefilter-1041995900.html |archive-url=https://web.archive.org/web/20230608082346/https://www.villeroy-boch.de/shop/coffee-passion-doppelwandiger-kaffeefilter-1041995900.html |archive-date=2023-06-08 |title=Coffee Passion doppelwandiger Kaffeefilter Villeroy & Boch}}</ref> the Brewista Tornado Duo filters<!-- at least since 2023 -->, or the Etkin 8-cup<!-- since 2022 --> and 2-cup<!-- since 2023 --> drippers), {{anchor|Radial infusion}}radial water feeding (like with the Ceado Hoop<!-- 2023 -->), or a collapsible design for easier storage
* accessories like a water spreader<!-- like the Melodrip --> or cover lid or top-plate to help water distribution and reduce the temperature decline during pouring<!-- like the Clever Dripper or Goat Story GINA Smart Brewer -->, a saucer to catch coffee droplets after use, a mounting stand, <!-- a coffee measurement spoon or scale, a stirring spoon, a metal cone to press filter paper into shape (early Melitta-style) --> or coffee chilling stones<!-- like Nucleus Paragon Chilling Rocks -->.

Metal and porcelain filter holders store more heat than glass or plastic filters and therefore should be [[:wikt:preheating|pre-heat]]ed to avoid too large temperature drops during pouring.

== See also ==
{{Commons category|Coffee filters}}
* [[Drip brew]]
* [[Coffee pod]] (coffee bag)
* [[Single-serve coffee container]]
* [[Ground coffee filter ring]]
* [[Tea bag]] or [[tea ball]]
* [[Used coffee grounds]]
* [[Health effects of coffee]]
* [[Neapolitan flip coffee pot]]

== Notes ==
[[File:Kaffeefilter.jpg|thumb|Melitta porcelain filter holder "102" with too large paper filter bag "1×4"<ref group="nb" name="NB_Melitta-fan"/>]]
{{reflist|group="nb"|refs=
<ref group="nb" name="NB_Health">Since filters and filter holders get in direct contact with hot water and coffee, an [[acidic]] solution, they should meet all criteria for [[food contact materials]], which some materials, depending on local regulatories, may not. This holds particularly true for materials used in some older or historic filters. [[Metal]] [[alloy]]s may contain problematic ingredients like [[lead-free|lead]] (Pb), [[nickel]] (Ni) or [[chromium]] (Cr). [[Aluminium]] (Al) is suspected to cause [[Alzheimer disease]]. Various [[plastic]]s may contain [[bisphenol A]] (BPA), [[bisphenol F]] (BPF), [[bisphenol S]] (BPS), [[phthalate]]s, etc. [[Food-grade]] [[stainless steel]] and [[ceramics]], and in particular [[silicate]]-based [[glass]] and [[porcelain]] are considered safe.</ref>
<ref group="nb" name="NB_Melitta-confusion">Fan- or boat-shaped filters of size #1 (Melitta 101) must not be confused with paper filter sizes Melitta 1 for round filter disks or Hario 01 for cone-shaped filters.</ref>
<ref group="nb" name="NB_Melitta-fan">Fan- or boat-shaped filters of size #2 (Melitta 102) must not be confused with the fan- or boat-shaped paper filter size Melitta 1×2, cone-shaped filter size Hario 02, or with Melitta 2 round filter disks. Melitta 102 has a different geometry and is significantly larger than Melitta 1×2, almost as large as Melitta 1×4. The size #2 Ritzenhoff & Breker "Rio 101" porcelain filter holder incorrectly associates this with size 101.<!-- https://web.archive.org/web/20230326183031/https://www.ebay-kleinanzeigen.de/s-anzeige/weisser-ritzenhoff-breker-rio-kaffeefilter-101-neu-ovp/2172258926-86-4441 --></ref>
<ref group="nb" name="NB_Melitta-4">Fan- or boat-shaped filters of size #4 (Melitta 1×4) must not be confused with the much larger fan- or boat-shaped filter size Melitta 104. Still, the size #4 Ritzenhoff & Breker "Rio 104" porcelain filter holder incorrectly associates this with size 104.<!-- https://web.archive.org/web/20230326183841/https://www.amazon.de/Ritzenhoff-Breker-Porzellan-Kaffeefilter-Filtert%C3%BCten/dp/B06XKX1SYD/ref%3Dsr_1_1?__mk_de_DE=%25C3%2585M%25C3%2585%25C5%25BD%25C3%2595%25C3%2591&crid=1F28D9G8CTD7Z --></ref>
<ref group="nb" name="NB_Melitta-6">Fan- or boat-shaped filters of size #6 (Melitta 1×6) must not be confused with the much larger fan- or boat-shaped filter size Melitta 106.</ref>
<ref group="nb" name="NB_Melitta-tm">Another reason for this easier nomenclature becoming more popular is because Melitta has trademarked the names of their filter bag sizes at least in Germany.</ref>
<ref group="nb" name="NB_Cafestol">[[Cafestol]] has also shown anticarcinogenic and neuroprotective properties at least in animals like rats and fruit flies.</ref> 
}}

== References ==
{{Reflist|refs=
<ref name="Ciupka_1931">{{cite book |title=Taschenbuch des Kaffee-Fachmanns |language=de |trans-title=Pocketbook of the coffee expert |chapter=Vor- und Nachteile des Filtrierpapierverfahrens |trans-chapter=Advantages and disadvantages of the paper filter method |author-first=Paul |author-last=Ciupka |date=1931 |edition=1 |location=Hamburg, Germany |publication-place=Hamburg, Germany |publisher={{ill|Otto Meissners Verlag|de}} / <!-- printed by-->Herrosé & Ziemsen GmbH |pages=213–214 [214] |quote-page= |quote=}} (viii+319 pages)</ref>
<ref name="Cárdenas-Quesada-Medina_2011">{{cite journal |title=Anti-Angiogenic and Anti-Inflammatory Properties of Kahweol, a Coffee Diterpene. |author-last1=Cárdenas |author-first1=Casimiro |author-last2=Quesada |author-first2=Ana R. |author-last3=Medina |author-first3=Miguel A. |editor-first=David L. |editor-last=McCormick |journal=[[PLoS One]] |volume=6 |issue=8 |date=2011-08-09 |pages=e23407 |pmid=21858104 |doi=10.1371/journal.pone.0023407 |doi-access=free |pmc=3153489 |bibcode=2011PLoSO...623407C}} [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3206792/ Correction]</ref>
<ref name="Cornelis-El-Sohemy_2007">{{cite journal |title=Coffee, caffeine, and coronary heart disease |author-last1=Cornelis |author-first1=Marilyn C. |author-last2=El-Sohemy |author-first2=Ahamed |s2cid=35221890 |journal=[[<!--:d:Q15757962|-->Current Opinion in Clinical Nutrition & Metabolic Care<!-- Curr Opin Clin Nutr Metab Care -->]] |volume=10 |issue=6 |publisher=[[Lippincott Williams & Wilkins, Inc.]] |date=November 2007 |pmid=18089957 |doi=10.1097/MCO.0b013e3282f05d81 |issn=1363-1950 |pages=745–751 |quote=[[Diterpene]]s present in unfiltered coffee and [[caffeine]] each appear to increase risk of [[coronary heart disease]]. A lower risk of coronary heart disease among moderate coffee drinkers might be due to [[antioxidant]]s found in coffee.}}</ref>
<ref name="Bellis_2017">{{cite web |title=Love Your Latte? This is the History of Coffee |author-first=Maria |author-last=Bellis |website=ThoughtCo |date=2017-04-07 |department=Humanities: History & Culture |url=https://www.thoughtco.com/history-of-how-we-make-coffee-1991478 |access-date=2023-03-19 |url-status=live |archive-url=https://web.archive.org/web/20230319184756/https://www.thoughtco.com/history-of-how-we-make-coffee-1991478 |archive-date=2023-03-19}}</ref>
<ref name="DPMA_2023">{{cite web |title=The invention of the coffee filters – Melitta Bentz, mother of filter coffee: Inventor and entrepreneur |publisher=[[German Patent and Trade Mark Office]] (DPMA) |date=2023-01-27 |url=https://www.dpma.de/english/our_office/publications/ingeniouswomen/110jahrekaffeefilter/index.html |access-date=2023-01-29 |url-status=live |archive-url=https://web.archive.org/web/20230129112701/https://www.dpma.de/english/our_office/publications/ingeniouswomen/110jahrekaffeefilter/index.html |archive-date=2023-01-29}}</ref>
<ref name="Hoffmann_2018">{{cite book |title=The World Atlas of Coffee |author-last=Hoffmann |author-first=James Alexander |author-link=James Alexander Hoffmann |edition=2 |publisher=Mitchell Beazley |date=2018 |isbn=978-1-78472-429-0 |location=Great Britain |pages=84}}</ref>
<ref name="Siems_2015">{{cite book |title=Melitta und Friesland Porzellan - 60 Jahre Keramikherstellung in Varel |language=de |trans-title=Melitta and Friesland Porzellan - 60 years manufacturing of ceramics in Varel |editor-first=Maren |editor-last=Siems |author-first1=Antje |author-last1=Sander |author-first2=Maren |author-last2=Siems |author-first3=Wilfried |author-last3=Wördemann |author-first4=Stefan |author-last4=Meyer |author-first5=Nina |author-last5=Janssen |publisher={{ill|Isensee Verlag|de}} |publication-place=Oldenburg, Germany |series={{ill|Schlossmuseum Jever|de|lt=Schloss Museum Jever}} |id=Begleitkatalog zur Ausstellung: Jeverland – in Ton gebrannt |edition=1 |volume=Jever Heft 33 |date=2015 |isbn=978-3-7308-1177-1 |pages=23, 42}} (48 pages)</ref>
<ref name="Brockhaus_1837">{{cite book |chapter=Kaffee |language=de-NHG |trans-title= |title=Bilder-Conversations-Lexikon für das deutsche Volk |edition=1 |publisher=[[F. A. Brockhaus]] |publication-place=Leipzig, Germany |date=1837 |url=http://www.zeno.org/Brockhaus-1837/A/Kaffee |access-date=2018-07-02 |url-status=live |archive-url=https://web.archive.org/web/20210927173311/http://www.zeno.org/Brockhaus-1837/A/Kaffee |archive-date=2021-09-27 |quote=Besser ist es, den Kaffee in einen Filtrirsack zu thun und das siedende Wasser darauf zu gießen. |trans-quote=}}</ref>
<ref name="Pierer_1865">{{cite book |chapter=Kaffee |language=de-NHG |trans-title= |title=Pierer's Universal-Lexikon der Vergangenheit und Gegenwart |edition=4 |publisher=Verlagsbuchhandlung von [[Heinrich August Pierer|H. A. Pierer]] |publication-place=Altenburg, Germany |orig-date=1857 |date=1865 |url=http://www.zeno.org/Pierer-1857/A/Kaffee |access-date=2018-07-02 |url-status=live |archive-url=https://web.archive.org/web/20220128094935/http://www.zeno.org/Pierer-1857/A/Kaffee |archive-date=2022-01-28 |quote=Gewöhnlich aber filtrirt man ihn noch vor dem Gebrauch, Andere aber bereiten ihn auch durch mehrmaliges Aufgießen siedenden Wassers über, in seine Leinwand gethanen gemahlenen K. |trans-quote=}}</ref>
<ref name="Tverdal-Selmer-Cohen-Thelle_2020">{{cite journal |title=Coffee consumption and mortality from cardiovascular diseases and total mortality: Does the brewing method matter? |author-first1=Aage |author-last1=Tverdal |author-first2=Randi |author-last2=Selmer |author-first3=Jacqueline M. |author-last3=Cohen |author-first4=Dag S. |author-last4=Thelle |date=2020-04-22 |journal=[[European Journal of Preventive Cardiology]] |issn=2047-4873 |eissn=2047-4881 |publisher=[[SAGE Publishing]] |volume=27 |issue=18 |pages=1986–1993 |doi=10.1177/2047487320914443 |doi-access=free |pmid=32320635 |s2cid=216083549 |quote=Unfiltered brew was associated with higher mortality than filtered brew, and filtered brew was associated with lower mortality than no coffee consumption.}}</ref>
<ref name="LaMotte_2020">{{cite web |title=The healthiest way to brew your coffee – and possibly lengthen your life |author-first=Sandee |author-last=LaMotte |work=[[CNN]] |date=2022-04-22 |url=https://edition.cnn.com/2020/04/22/health/healthiest-coffee-brew-wellness/index.html |access-date=2023-12-26 |url-status=live |archive-url=https://web.archive.org/web/20231226183842/https://amp.cnn.com/cnn/2020/04/22/health/healthiest-coffee-brew-wellness/index.html |archive-date=2023-12-26}}</ref>
<ref name="Krünitz_1784">{{cite book |title=Oekonomische Encyklopädie, oder allgemeines System der Stats- Stadt- Haus- u. Landwirthschaft, in alphabetischer Ordnung |language=de-ENHG |trans-title=Economic encyclopedia |title-link=Oekonomische Encyklopädie |chapter=Kaffe |trans-chapter=Coffee |author-first=Johann Georg |author-last=Krünitz |author-link=Johann Georg Krünitz |editor-first=Johann Friedrich |editor-last=von Pfeiffer |editor-link=Johann Friedrich von Pfeiffer |date=1784 |issue=32 (Von Ka. bis Kal.) |publisher={{ill|Joachim Pauli|de}} |publication-place=Berlin |pages=100–264 [172] |chapter-url=https://books.google.com/books?id=-pkUAAAAQAAJ&pg=P172 |access-date=2023-06-03 |url-status=live |archive-url=https://web.archive.org/web/20230603133615/https://books.google.de/books?id=-pkUAAAAQAAJ&pg=P172#v=onepage&q&f=false |archive-date=2023-06-03 |quote-pages=172–173 |quote=Die neuerlich eingeführte Weise, den Kaffetrank durch das Filtriren zu verfertigen, ist wohl unstreitig die beste. Man legt nähmlich in einen dazu gemachten blechernen, wohl verzinnten, Filtrirhut oder Trichter, (Kaffe-Sieb) ein reines, feines Leinwand-Tüchlein oder Haartuch, oder, weil dieses durch den öfteren Gebrauch leicht unrein gemacht werden könnte, lieber weißes Lösch- und Druck-Papier, und nimmt jedes Mahl neues; in dieses schüttet man den gemahlenen Kaffe, setzt den Trichter über einen erwärmten Topf oder Kanne, und gießt allmählich siedendes Wasser darauf. Auf solche Art zieht das Wasser aus dem Kaffe die Kräfte, und filtrirt ganz klar durch das Tuch oder Papier. Das Wasser aber muß langsam aufgegossen werden; man könnte auch, um die Kraft destobesser auszuziehen, diesen durchgeseiheten Trank nochmahl in den Trichter zurück gießen, und durch den gemahlenen Kaffee zum zweiten Mahl laufen lassen. Ein solcher filtrirter Kaffe ist nicht nur gesunder, als der abgekochte, sondern hat auch noch andere Vorzüge. Man kann solchen nicht nur nach Belieben wieder erwärmen und aufkochen, und er bleibt immer klar, sondern der Geschmack ist auch besser, welches leicht daraus abzunehmen ist, weil der in dem Trichter zurück gebliebene Kaffe nicht, wie der andere, der im Topfe sich zu Boden setzt, nochmahl auf- und ausgekochet werden kann, und, wenn solches ja geschähe, man ein Getränk erhält, welches gar nicht nach Kaffee schmeckt, sondern einen recht wiederlichen Geschmack hat. |trans-quote=}}</ref>
<ref name="Bramah_1995">{{cite book |title=Coffee Makers – 300 years of art & design |author-first1=Edward Roderick |author-last1=Bramah |author-first2=Joan |author-last2=Bramah |edition=2 |date=1995 |orig-date=1989 |translator-first=Georg |translator-last=Auerbach |publisher=Quiller Press Ltd. |publication-place=London, UK |isbn=1-870948-33-5}} (2+2+166+8+2 pages) (NB. Original 1989 edition was by Lucchetti editore, Bergamo, Italy.); {{cite book |title=Kaffeemaschinen - Die Kulturgeschichte der Kaffeeküche |language=de |trans-title=Coffeemachines - The cultural history of the coffee kitchen |author-first1=Edward Roderick |author-last1=Bramah |author-first2=Joan |author-last2=Bramah |edition=Special |date=1995 |orig-date=1989 |translator-first=Georg |translator-last=Auerbach |publisher=Parkland Verlag (originally: Blanckenstein Verlag) |publication-place=Stuttgart, Germany (originally: Munich, Germany) |isbn=3-88059-826-6 |page=152}} (168+2 pages) (NB. The German translation contains many typographical errors.)</ref>
<ref name="Beutelspacher_2006">{{cite book |chapter=Techniken der Kaffeezubereitung. Auf dem Weg zu einer Optimierung des Kaffeegenusses |language=de |trans-title= |author-first=Martin |author-last=Beutelspacher |editor-first=Ruth-Elisabeth |editor-last=Mohrmann |editor-link=:de:Ruth-Elisabeth Mohrmann |title=Essen und Trinken in der Moderne |series=Beiträge zur Volkskultur in Nordwestdeutschland |publisher={{ill|Waxmann Publishing|de|Waxmann Verlag|lt=Waxmann Verlag GmbH / Waxmann Publishing Co.}} |edition=1 |publication-place=Münster, Germany; New York, USA |date=July 2006 |isbn=978-3-8309-1701-4 |issn=0724-4096 |pages=125–146 |chapter-url=https://books.google.com/books?id=nvUWJZe4u24C&pg=PA125 |access-date=2023-06-09}} (159+1 pages)</ref>
<ref name="jam_2008">{{cite news |title=Kaffee-Revolution mit Blechdose und Löschpapier |language=de |trans-title= |author=jam |department=Saarland |date=2008-06-19 |newspaper=[[Saarbrücker Zeitung]] |url=https://www.saarbruecker-zeitung.de/saarland/kaffee-revolution-mit-blechdose-und-loeschpapier_aid-136226 |access-date=2023-06-03 |quote=Denn die Methode, mittels Löschpapier und einem blechernen Trichter Kaffee zuzubereiten, wird bereits in der 1784 erschienenen "{{citeref|Krünitz |1784|Oeconomischen Encyclopädie|style=plain}}" von [[Johann Georg Krünitz]] unter dem äußerst ausführlichen Eintrag "Kaffe" als bekannt vorausgesetzt – und als beste Art der Kaffeebereitung gepriesen. Aber offenbar hatte sich zuvor noch niemand die Mühe gemacht, diese Idee zu Geld zu machen. |trans-quote=}}</ref>
<ref name="Bersten_1993">{{cite book |title=Coffee floats, tea sinks. Through History and Technology to a Complete Understanding |author-first1=Ian |author-last1=Bersten |author-first2=Helen |author-last2=Bersten |date=1993 |edition=1 |publisher=Helian Books |publication-place=Sydney / Roseville, Australia |isbn=0-646-09180-8}} (284+4 pages)</ref>

<ref name="Böhnke-Reich_1885">{{cite book |title=Der Kaffee in seinen Beziehungen zum Leben. Für Haus und Familie und für Gebildete aller Stände. Festschrift zum zweihundertjährigen Jubiläum des Kaffee's in Österreich und Deutschland |language=de-NHD |trans-title= |author-first=Heinrich |author-last=Böhnke-Reich<!-- also as: Boehnke-Reich --> |date=1885 |edition=2nd expanded |publisher=Verlag von Fr. Thiel |location=Berlin & Leipzig, Germany}} (xii+224 pages)</ref>
<ref name="Holzborn_1928">{{cite book |title=Der Eisenwarenhandel. Ein Lehr- u. Nachschlagewerk für den Handel mit Eisenwaren und Haus- und Küchengeräten |language=de |trans-title= |author-first=Adolf |author-last=Holzborn |date=c. 1928 |edition=1 |publisher=Heinrich Killinger Verlagsgesellschaft |location=Nordhausen, Germany |page=977}}</ref>
<ref name="Ciupka_1949">{{cite book |title=Kaffee-Ersatz und Kaffee-Zusatz |language=de |trans-title= |author-first=Paul |author-last=Ciupka |date=1949 |volume=1 |publisher={{ill|Otto Meissners Verlag|de}} |location=Hamburg, Germany |page=47}}</ref>
<ref name="Jöcher_1825">{{cite magazine |title=Kaffee, Thee und Chocolade |language=de-NHD |trans-title= |editor-first=G. A. |editor-last=Jöcher |magazine=Jöcher<!-- written with and without ' -->s gemeinnützige Magie |publisher=Literarisches Central-Comptoir |issue=Heft 17 |volume= |date=1825 |location=Leipzig, Germany}}</ref>
<ref name="Prince_2023">{{cite web |title=There's No Bypassing the NextLevel Brewers |author-first=Mark |author-last=Prince |date=2023-07-20 |work=Coffeegeek |url=https://www.coffeegeek.com/new-products/theres-no-bypassing-the-nextlevel-brewers/ |access-date=2023-12-29 |url-status=live |archive-url=https://web.archive.org/web/20231229160311/https://www.coffeegeek.com/new-products/theres-no-bypassing-the-nextlevel-brewers/ |archive-date=2023-12-29}}</ref>
<ref name="Rosenthal_Cup-filter">{{cite web |title=Tassenfilter – Der neue Tassenfilter Marke Rosenthal |language=de-NHD |trans-title=The new cup filter |date=<!-- 19?? --> |publisher=[[Rosenthal (company)|Rosenthal]] |publication-place=Nürnberg, Germany |url=https://www.sampor.de/assets/images/getraenke-und-co/filter/ga_tassenfilter_rosenthal_01.jpg |access-date=2023-12-31 |url-status=live |archive-url=https://web.archive.org/web/20231231191454/https://www.sampor.de/assets/images/getraenke-und-co/filter/ga_tassenfilter_rosenthal_01.jpg |archive-date=2023-12-31 |quote=Der Kaffee kommt mit keinem Metall in Berührung, behält daher sein natürliches Aroma. […] Durch Verwendung des doppelt geschlitzten, durchaus glasierten Siebes, kommt das lästige Filtrierpapier, das dem Kaffeearoma schädlich ist, in Fortfall. |trans-quote=}}</ref>
<ref name="Gloess-Schönbächler-Klopprogge-DAmbrosio-Chatelain-Bongartz-Strittmatter-Rast-Yeretzian_2013">{{cite journal |title=Comparison of nine common coffee extraction methods: instrumental and sensory analysis |author-first1=Alexia N. |author-last1=Gloess |author-first2=Barbara |author-last2=Schönbächler |author-first3=Babette |author-last3=Klopprogge |author-first4=Lucio |author-last4=D'Ambrosio |author-first5=Karin |author-last5=Chatelain |author-first6=Annette |author-last6=Bongartz |author-first7=André |author-last7=Strittmatter |author-first8=Markus |author-last8=Rast |author-first9=Chahan |author-last9=Yeretzian |location=Wädenswil & Zürich, Switzerland |journal={{ill|European Food Research and Technology|d|Q186703}} |issn=1438-2377 |eissn=1438-2385 |publisher=[[Springer Science+Business Media]] |volume=236 |issue=4 |date=April 2013 |orig-date=2012-06-05, 2013-01-08, 2013-01-10, 2013-01-30 |doi=10.1007/s00217-013-1917-x |doi-access=free |s2cid=31366362 |pages=607–627 |url=https://link.springer.com/content/pdf/10.1007/s00217-013-1917-x.pdf |access-date=2023-12-31 |url-status=live |archive-url=https://web.archive.org/web/20231231222635/https://link.springer.com/content/pdf/10.1007/s00217-013-1917-x.pdf |archive-date=2023-12-31}} (21 pages) ([https://web.archive.org/web/20231231222644/https://static-content.springer.com/esm/art%3A10.1007%2Fs00217-013-1917-x/MediaObjects/217_2013_1917_MOESM1_ESM.docx Supplemental material])</ref>
<ref name="Hempe_2008">{{cite book |title=100 Jahre Melitta – Geschichte eines Markenunternehmens |language=de |trans-title=100 years Melitta – History of a brand company |date=2008 |edition=1 |author-first=Mechthild |author-last=Hempe |editor=Melitta Unternehmensgruppe |editor-link=Melitta Unternehmensgruppe |location=Minden, Germany |publisher=Geschichtsbüro Verlag / Geschichtsbüro Reder, Roeseling & Prüfer GbR |publication-place=Cologne, Germany |isbn=978-3-940371-12-6}} (2+140+2 pages) (NB. There is also a French translation named {{lang|fr|100 années Melitta - L'histoire d'une marque}}. Reportedly, English and Brazilian translations exist as well.)</ref>
<ref name="Eberswalder_1931">{{cite news |title=(unknown)<!-- TBD --> |language=de |trans-title= |newspaper=Eberswalder Offertenblatt - Organ für die deutschen Eisen-, Stahl-, Kurzwaren- u. Haushaltungs-Geschäfte sowie für die Werkzeug- u. Werkzeugmaschinen-Branche |publication-place=Eberswalde, Germany |publisher= |date=September 1931<!-- exact date TBD --> |volume=55 |number=4xxx<!-- unknown, but must be between 4000 and 4299 --> |issue= |oclc=183226441 |id={{ZDB|614542-5}}. {{DNB-IDN|013563963}} |pages=<!-- TBD --> |quote-page= |quote=<!-- referring to the Brasilfilter: -->gut und zweckmäßig}}</ref>
<ref name="Kampmann_2018">{{cite web |title=Selten! Melitta Urfilter "Brasilfilter" "Brasil" Kaffeefilter, Größe 2, 30er J. • EUR 289,80 |website=PicClick DE |url=https://picclick.de/Selten-Melitta-Urfilter-Brasilfilter-Brasil-Kaffeefilter-Gr%C3%B6%C3%9Fe-2-132858082941.html}}<!-- https://www.facebook.com/861299117320682/posts/1183122335138357/ Excerpts from former ebay auction: "Brasil" Kaffeefilter Gr. 2. D.R.G.M. Wahrscheinlich um die Jahreswende 1931/1932 kaufte Melitta den "Brasilfilter" mit allen Rechten auf, denn dieser hatte sich – ebenso wie der "Blitzfilter" – zu einer ernstzunehmenden Konkurrenz für die Rundfilter, die Melitta verkaufte, entwickelt. Der "Brasilfilter" und auch der "Blitzfilter" waren technisch weiter entwickelt, da der Filtervorgang durch die konische Form und durch die Rippung in den inneren Seitenwänden wesentlich schneller und hygienischer ablief als bei den Melitta-Rundfiltern. Am 16. März 1932 meldete Melitta dann den Filter unter eigenem Namen zum Patent an, verkaufte ihn als Schnell-Filter und versah ihn zunächst mit einem Aufdruck in Rot oder Grün. Ab ca. 1933 wurde der Aufdruck dann in der Farbe Blau-Grün ausgeführt und das Aussehen des Filters bei der Stärke der Aufsatzplatte und der Henkelform geringfügig modifiziert. Der "Brasil" Kaffeefilter muss zwischen 1930 und 1931 hergestellt worden sein. Der Eintrag in das "Gebrauchsmuster-Register" war 1930 erfolgt, und zwar auf den Namen O. Schulz, Berlin. Den Filter gibt es in vier Größen (0, 1, 2 und 3) und mit unterschiedlichen Aufdrucken ("Brasil" Kaffeefilter; "Brasilfilter"). Höhe: ca. 9,1 cm; oberer innerer Durchmesser: ca. 10,4 cm --></ref>
<ref name="Kampmann_2024">Personal correspondence with Astrid and Günther Kampmann, Willich, Germany. September 2024. See also: {{citeref|Treffer|2016|Treffer 2016|style=plain}}.</ref>
<ref name="Treffer_2016">{{cite news |title=Erst mahlen, dann filtern – Astrid und Günther Kampmann haben ein Faible: Kaffeefilter. Das Willicher Ehepaar besitzt eine Melitta-Filter-Sammlung von rund 600 Exemplaren. |language=de |trans-title= |author-first=Bianca |author-last=Treffer |date=2016-03-01 |newspaper=[[Rheinische Post]] |department=NRW > Städte > Stadt Willich |issn= |volume=70 |number= |publisher=[[Rheinische Post Verlagsgesellschaft mbH]] |pages= |url=https://rp-online.de/nrw/staedte/willich/erst-mahlen-dann-filtern_aid-21365993 |access-date=2024-09-10 |url-status=live |archive-url=https://web.archive.org/web/20240910181143/https://rp-online.de/nrw/staedte/willich/erst-mahlen-dann-filtern_aid-21365993 |archive-date=2024-09-10}}</ref>
}}

== Further reading ==
* {{cite book |title=The Physics of Filter Coffee |chapter=5. Filters |author-first=Jonathan |author-last=Gagné |author-link=:d:Q56561291 |editor-first=Jean |editor-last=Zimmer |publisher=Scott Rao |date=2020<!-- 2020-10-23? --> |edition=1 |isbn=978-0-578-24608-6 |pages=105–125}} [https://web.archive.org/web/20230227202755/https://www.scottrao.com/the-physics-of-filter-coffee The Physics of Filter Coffee — Scott Rao] (xvi+249+3 pages)

{{coffee}}
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[[Category:Water filters]]
[[Category:Food preparation utensils]]
[[Category:German inventions]]
[[Category:Coffee preparation]]
[[Category:Products introduced in 1908]]
[[Category:1908 in Germany]]