Editing Leavening agent (section)

{{Short description|Substance which liberates gas and thereby increases the volume of a dough or batter}}
{{For|the village|Leavening, North Yorkshire}}
{{broader|Bread#Leavening{{!}}Bread leavening}}
{{more citations needed|date=July 2014}}

In [[cooking]], a '''leavening agent''' ({{IPAc-en|ˈ|l|ɛ|v|ən|ɪ|ŋ}}) or '''raising agent''', also called a '''leaven''' ({{IPAc-en|ˈ|l|ɛ|v|ən}}) or '''leavener''', is any one of a number of substances used in [[dough]]s and [[batter (cooking)|batters]] that cause a [[Effervescence|foaming action]] (gas bubbles) that lightens and softens the mixture. An alternative or supplement to leavening agents is mechanical action by which air is incorporated (i.e. [[kneading]]). Leavening agents can be biological or synthetic [[chemical compound]]s. The gas produced is often [[carbon dioxide]], or occasionally [[hydrogen]].<ref>{{Cite book |last=Jacobs |first=Morris Boris |title=The Chemistry and Technology of Food and Food Products |publisher=Interscience Publishers |year=1951 |location=Hoboken, NJ |pages=1932 |language=en}}</ref>

When a dough or batter is mixed, the [[starch]] in the flour and the water in the dough form a [[Matrix (biology)|matrix]]<ref>{{Cite book |last=Hanft |first=Steven L. |title=Fachenglisch für Laborberufe |publisher=John Wiley & Sons |year=2016 |isbn=978-3-527-33512-1 |location=Weinheim |pages=208 |language=en}}</ref> (often supported further by [[protein]]s like [[gluten]] or [[polysaccharides]], such as [[pentosan]]s or [[xanthan gum]]). The starch then [[starch gelatinization|gelatinizes]] and sets, leaving gas bubbles that remain.