Editing Potassium bitartrate (section)

==Applications==

===In food===
{{Cookbook|Cream of Tartar}}[[File:Folgers Cream Tartar etc.jpg|thumb|Folger's Golden Gate Cream Tartar, first half of 20th century]]
In food, potassium bitartrate is used for:
* Stabilizing [[egg white]]s, increasing their warmth-tolerance and volume<ref name="science">{{cite book |title=The science of good cooking : master 50 simple concepts to enjoy a lifetime of success in the kitchen |date=2012 |publisher=America's Test Kitchen |isbn=978-1-933615-98-1 |page=199 |edition=1st}}</ref>
* Stabilizing [[whipped cream]], maintaining its texture and volume<ref>{{cite web |title=How to Use Cream of Tartar |url=https://www.wikihow.com/Use-Cream-of-Tartar |website=wikiHow |access-date=28 May 2019 |archive-date=28 May 2019 |archive-url=https://web.archive.org/web/20190528110909/https://www.wikihow.com/Use-Cream-of-Tartar |url-status=dead }}</ref>
* [[Anti-caking agent|Anti-caking]] and [[Thickening agent|thickening]]<ref>{{cite web |last1=Stephens |first1=Emily |title=The Incredible Cream of Tartar – How to Use and What to Substitute With |url=https://www.mygreatrecipes.com/blog/incredible-cream-tartar-use-substitute/ |website=MyGreatRecipes |access-date=28 May 2019  |date=18 February 2017}}</ref>
* Preventing [[sugar syrup]]s from [[Crystallization|crystallizing]] by causing some of the [[sucrose]] to break down into [[glucose]] and [[fructose]]<ref name="Provost">{{cite book |last1=Provost |first1=Joseph J. |last2=Colabroy |first2=Keri L. |last3=Kelly |first3=Brenda S. |last4=Wallert |first4=Mark A. |title=The Science of Cooking : Understanding the Biology and Chemistry Behind Food and Cooking |date=2016 |publisher=John Wiley and Sons, Inc. |isbn=9781118674208 |page=504 |url=https://books.google.com/books?id=9ydECwAAQBAJ&pg=PA503}}</ref>
* Reducing discoloration of boiled [[vegetable]]s

Additionally, it is used as a component of:
* [[Baking powder]], as an acid ingredient to activate [[baking soda]]<ref>{{cite book |last1=McGee |first1=Harold |title=On food and cooking : the science and lore of the kitchen |date=2004 |publisher=Scribner |isbn=978-0-684-80001-1 |page=533,534 |edition=2nd}}</ref>
* [[Salt substitute|Salt substitutes]], in combination with [[potassium chloride]]

A similar acid salt, [[sodium acid pyrophosphate]], can be confused with cream of tartar because of its common function as a component of baking powder.

=== Baking ===
Adding cream of tartar to egg whites gives volume to cakes, and makes them more tender.<ref name=":3">{{Cite journal |last1=Oldham |first1=A. M. |last2=Mccomber |first2=D. R. |last3=Cox |first3=D. F. |date=2000-12-01 |title=Effect of Cream of Tartar Level and Egg White Temperature on Angel Food Cake Quality |url=http://doi.wiley.com/10.1177/1077727X00292003 |journal=Family and Consumer Sciences Research Journal |language=en |volume=29 |issue=2 |pages=111–124 |doi=10.1177/1077727X00292003 |issn=1077-727X|url-access=subscription }}</ref> As cream of tartar is added, the pH decreases to around the isoelectric point of the foaming proteins in egg whites. Foaming properties of egg whites are optimal at this pH due to increased protein-protein interactions.<ref>{{Cite journal |last1=Waniska |first1=R. D. |last2=Kinsella |first2=J. E. |title=Foaming Properties of Proteins: Evaluation of a Column Aeration Apparatus Using Ovalbumin |date=1979 |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1979.tb06447.x |journal=Journal of Food Science |language=en |volume=44 |issue=5 |pages=1398–1402 |doi=10.1111/j.1365-2621.1979.tb06447.x |issn=0022-1147|url-access=subscription }}</ref> The low pH also results in a whiter crumb in cakes due to flour pigments that respond to these pH changes.<ref name=":3" /> However, adding too much cream of tartar (>2.4% weight of egg white) can affect the texture and taste of cakes.<ref name=":3" /> The optimal cream of tartar concentration to increase volume and the whiteness of interior crumbs without making the cake too tender, is about 1/4 tsp per egg white.<ref name=":3" />

As an acid, cream of tartar with heat reduces sugar crystallization in [[Inverted sugar syrup|invert syrups]] by helping to break down [[sucrose]] into its monomer components - [[fructose]] and [[glucose]] in equal parts.<ref name=":2">{{Cite book |last=Figoni |first=Paula |title=How Baking Works: Exploring the Fundamentals of Baking Science |publisher=JOHN WILEY & SONS, INC |year=2007 |isbn=9780471747239 |edition=2nd}}</ref> Preventing the formation of sugar crystals makes the syrup have a non-grainy texture, shinier and less prone to break and dry. However, a downside of relying on cream of tartar to thin out crystalline sugar confections (like fudge) is that it can be hard to add the right amount of acid to get the desired consistency.

Cream of tartar is used as a type of [[acid salt]] that is crucial in [[baking powder]].<ref name=":2" /> Upon dissolving in batter or dough, the [[tartaric acid]] that is released reacts with [[Sodium bicarbonate|baking soda]] to form [[carbon dioxide]] that is used for [[Leavening agent|leavening]]. Since cream of tartar is fast-acting, it releases over 70 percent of carbon dioxide gas during mixing.

=== Household use ===
Potassium bitartrate can be mixed with an acidic liquid, such as lemon juice or white vinegar, to make a paste-like cleaning agent for metals, such as [[brass]], [[aluminium]], or [[copper]], or with water for other cleaning applications, such as removing light stains from [[porcelain]].<ref>{{cite web|url=http://www.msue.msu.edu/objects/content_revision/download.cfm/revision_id.499694/workspace_id.-4/01500631.html/ |archive-url=https://web.archive.org/web/20090623085023/http://www.msue.msu.edu/objects/content_revision/download.cfm/revision_id.499694/workspace_id.-4/01500631.html/ |url-status=dead |archive-date=2009-06-23 |title=Michigan State University Extension Home Maintenance And Repair – Homemade Cleaners – 01500631, 06/24/03 |access-date=2018-04-19}}</ref>
This mixture is sometimes mistakenly made with vinegar and [[sodium bicarbonate]] (baking soda), which actually [[Acid–base reaction|react]] to [[Neutralization (chemistry)|neutralize]] each other, creating [[carbon dioxide]] and a [[sodium acetate]] solution.

Cream of tartar was often used in traditional [[dyeing]] where the [[complexing]] action of the tartrate ions was used to adjust the solubility and [[hydrolysis]] of [[mordant]] salts such as [[Tin(II) chloride|tin chloride]] and [[alum]].

Cream of tartar, when mixed into a paste with [[hydrogen peroxide]], can be used to clean [[rust]] from some [[hand tool]]s, notably hand [[File (tool)|files]]. The paste is applied, left to set for a few hours, and then washed off with a baking soda/water solution. After another rinse with water and thorough drying, a thin application of oil will protect the file from further rusting.

Slowing the set time of [[Plaster|plaster of Paris]] products (most widely used in [[gypsum plaster]] wall work and artwork casting) is typically achieved by the simple introduction of almost any acid diluted into the mixing water. A commercial retardant premix additive sold by USG to trade interior plasterers includes at least 40% potassium bitartrate. The remaining ingredients are the same plaster of Paris and [[quartz]]-silica [[Construction aggregate|aggregate]] already prominent in the main product. This means that the only active ingredient is the cream of tartar.<ref>{{cite web|title=Material Safety Data Sheet: Gypsum Plaster Retarder for Lime-Based Products|url=https://www.usg.com/content/dam/USG_Marketing_Communications/canada/product_promotional_materials/finished_assets/gypsum-plaster-retarder-lime-based-products-en-can-53100112.pdf|publisher=USG Inc.|access-date=21 July 2016|archive-url=https://web.archive.org/web/20160829063803/https://www.usg.com/content/dam/USG_Marketing_Communications/canada/product_promotional_materials/finished_assets/gypsum-plaster-retarder-lime-based-products-en-can-53100112.pdf|archive-date=29 August 2016|url-status=dead}}</ref>

===Cosmetics===
For dyeing hair, potassium bitartrate can be mixed with [[henna]] as the mild acid needed to activate the henna.

===Medicinal use===
Cream of tartar has been used internally as a [[purgative]], but this is dangerous because an excess of potassium, or [[hyperkalemia]], may occur.<ref>{{cite journal | journal = [[Journal of Medical Toxicology]] | date = 2013 | volume = 9 | issue = 1 | pages = 79–81 | doi = 10.1007/s13181-012-0255-x | pmc = 3570668 | pmid=22926733 | title = Life-Threatening Hyperkalemia from Cream of Tartar Ingestion | first1 = Daniel E. | last1 = Rusyniak | first2 = Pamela J. | last2 = Durant | first3 = James B. | last3 = Mowry | first4 = Jo A. | last4 = Johnson | first5 = Jayne A. | last5 = Sanftleben | first6 = Joanne M. | last6 = Smith}}</ref><ref>{{Cite journal |last1=Rusyniak |first1=Daniel E. |last2=Durant |first2=Pamela J. |last3=Mowry |first3=James B. |last4=Johnson |first4=Jo A. |last5=Sanftleben |first5=Jayne A. |last6=Smith |first6=Joanne M. |date=March 2013 |title=Life-threatening hyperkalemia from cream of tartar ingestion |journal=Journal of Medical Toxicology|volume=9 |issue=1 |pages=79–81 |doi=10.1007/s13181-012-0255-x |issn=1937-6995 |pmc=3570668 |pmid=22926733}}</ref>

===Chemistry===
Potassium bitartrate is the United States' [[National Institute of Standards and Technology]]'s primary reference standard for a [[Buffer solution|pH buffer]].  Using an excess of the salt in water, a [[saturated solution]] is created with a [[pH]] of 3.557 at {{convert|25|°C}}. Upon dissolution in water, potassium bitartrate will [[dissociate]] into acid tartrate, tartrate, and potassium [[ions]]. Thus, a saturated solution creates a buffer with standard pH. Before use as a standard, it is recommended that the solution be filtered or [[Decantation|decanted]] between {{convert|22|°C}} and {{convert|28|°C}}.<ref>{{citation|last=Harris|first=Daniel C.|title=Quantitative Chemical Analysis|edition=7th|publisher=[[W. H. Freeman]]|place=New York|date=17 July 2006|isbn=978-0-7167-7694-9}}</ref>

[[Potassium carbonate]] can be made by burning cream of tartar, which produces "[[pearl ash]]". This process is now obsolete but produced a higher quality (reasonable purity) than "[[potash]]" extracted from wood or other plant ashes.