Changes

==Origin==

==Origin==

French ''levain'' (recorded from 12–13th century) = Provençal ''levam'' < [[Latin]] ''levāmen'' means of raising (recorded only in the sense ‘alleviation, relief, [[comfort]]’), < ''levāre'' (French [[lever]] ) to raise.

French ''levain'' (recorded from 12–13th century) = Provençal ''levam'' < [[Latin]] ''levāmen'' means of raising (recorded only in the sense ‘alleviation, relief, [[comfort]]’), < ''levāre'' (French [[lever]] ) to raise.

*[http://en.wikipedia.org/wiki/13th_century 13th Century]

*[https://en.wikipedia.org/wiki/13th_century 13th Century]

==Definitions==

==Definitions==

*1: a. A substance which is added to dough to produce [http://en.wikipedia.org/wiki/Fermentation fermentation]; spec. a [[quantity]] of fermenting dough reserved from a previous batch to be used for this [[purpose]]

*1: a. A substance which is added to dough to produce [https://en.wikipedia.org/wiki/Fermentation fermentation]; spec. a [[quantity]] of fermenting dough reserved from a previous batch to be used for this [[purpose]]

:b. In wider sense: Any substance that produces fermentation; = ferment; occasionally applied to the ‘ferment’ of zymotic [[diseases]].

:b. In wider sense: Any substance that produces fermentation; = ferment; occasionally applied to the ‘ferment’ of zymotic [[diseases]].

2:a. Chiefly with allusion to certain passages of the [[gospels]] (e.g. Matt. xiii. 33, xvi. 6): An [[agency]] which produces [[profound]] [[change]] by [[progressive]] inward operation.

2:a. Chiefly with allusion to certain passages of the [[gospels]] (e.g. Matt. xiii. 33, xvi. 6): An [[agency]] which produces [[profound]] [[change]] by [[progressive]] inward operation.

:b. A tempering or [[modifying]] [[element]]; a tinge or admixture (of some [[quality]].

:b. A tempering or [[modifying]] [[element]]; a tinge or admixture (of some [[quality]].

==Description==

==Description==

A leavening agent (also leavening or '''leaven'''; /ˈlɛvənɪŋ/ or /ˈlɛvən/) is any one of a number of substances used in [http://en.wikipedia.org/wiki/Dough doughs] and batters that cause a foaming action which lightens and softens the finished product. The leavening [[agent]] incorporates gas bubbles into the dough—this may be air incorporated by [[mechanical]] means, but usually it is carbon dioxide produced by [[biological]] agents, or by [[chemical]] agents reacting with [[moisture]], [[heat]], acidity, or other triggers. When a dough or batter is mixed, the [http://en.wikipedia.org/wiki/Starch starch] in the flour mixes with the [[water]] in the dough to form a matrix (often supported further by proteins like [http://en.wikipedia.org/wiki/Gluten gluten] or other polysaccharides like pentosans or xanthan gum), then [http://en.wikipedia.org/wiki/Starch_gelatinization gelatinizes] and "sets"; the holes left by the gas bubbles remain.[http://en.wikipedia.org/wiki/Leaven]

A leavening agent (also leavening or '''leaven'''; /ˈlɛvənɪŋ/ or /ˈlɛvən/) is any one of a number of substances used in [https://en.wikipedia.org/wiki/Dough doughs] and batters that cause a foaming action which lightens and softens the finished product. The leavening [[agent]] incorporates gas bubbles into the dough—this may be air incorporated by [[mechanical]] means, but usually it is carbon dioxide produced by [[biological]] agents, or by [[chemical]] agents reacting with [[moisture]], [[heat]], acidity, or other triggers. When a dough or batter is mixed, the [https://en.wikipedia.org/wiki/Starch starch] in the flour mixes with the [[water]] in the dough to form a matrix (often supported further by proteins like [https://en.wikipedia.org/wiki/Gluten gluten] or other polysaccharides like pentosans or xanthan gum), then [https://en.wikipedia.org/wiki/Starch_gelatinization gelatinizes] and "sets"; the holes left by the gas bubbles remain.[https://en.wikipedia.org/wiki/Leaven]

[[Category: Chemistry]]

[[Category: Chemistry]]