Editing Bread (section)

===Yeast===
{{Main|Baker's yeast}}
[[File:Compressed fresh yeast - 1.jpg|right|thumb|Compressed fresh yeast]]

Many breads are leavened by [[yeast]]. The yeast most commonly used for leavening bread is ''[[Saccharomyces cerevisiae]]'', the same species used for brewing alcoholic beverages. This yeast [[Fermentation|ferments]] some of the sugars producing [[carbon dioxide]]. Commercial bakers often leaven their dough with commercially produced [[baker's yeast]]. Baker's yeast has the advantage of producing uniform, quick, and reliable results, because it is obtained from a [[pure culture]].<ref name=BAC/> Many artisan bakers produce their own yeast with a growth culture. If kept in the right conditions, it provides leavening for many years.<ref name="isbn0-387-38563-0-cite4">{{cite book |author1=Young, Linda |author2=Cauvain, Stanley P. |title=Technology of Breadmaking |publisher=Springer |location=Berlin |year=2007 |page=79 |isbn=978-0-387-38563-1 |url=https://books.google.com/books?id=HXtJivmeDfcC&pg=PA79}}</ref>

The baker's yeast and [[sourdough]] methods follow the same pattern. Water is mixed with flour, salt and the leavening agent. Other additions (spices, herbs, fats, seeds, fruit, etc.) are not needed to bake bread, but are often used. The mixed dough is then allowed to [[Proofing (baking technique)|rise]] one or more times (a longer rising time results in more flavor, so bakers often "punch down" the dough and let it rise again), loaves are formed, and (after an optional final rising time) the bread is baked in an [[oven]].<ref name=BAC/>

Many breads are made from a "[[straight dough]]", which means that all of the ingredients are combined in one step, and the dough is baked after the rising time;<ref name=BAC/> others are made from a "[[pre-ferment]]" in which the leavening agent is combined with some of the flour and water a day or so ahead of baking and allowed to ferment overnight. On the day of baking, the rest of the ingredients are added, and the process continues as with straight dough. This produces a more flavorful bread with better texture. Many bakers see the starter method as a compromise between the reliable results of baker's yeast and the flavor and complexity of a longer fermentation. It also allows the baker to use only a minimal amount of baker's yeast, which was scarce and expensive when it first became available. Most yeasted pre-ferments fall into one of three categories: "[[poolish]]" or "pouliche", a loose-textured mixture composed of roughly equal amounts of flour and water (by weight); "[[biga (bread baking)|biga]]", a stiff mixture with a higher proportion of flour; and "pâte fermentée", which is a portion of dough reserved from a previous batch.<ref>{{cite web|title=Artisan bread baking tips: Poolish & biga|url=https://www.weekendbakery.com/posts/more-artisan-bread-baking-tips-poolish-biga/|website=Weekend Bakery|access-date=2 October 2016}}</ref><ref>{{cite web|title=Preferments|publisher=King Arthur Flour}}</ref>

<gallery mode="packed">
File:Breaddough1.jpg|Before first rising
File:Breaddough2.jpg|After first rising
File:Risen bread dough in tin.jpg|After [[proofing (baking technique)|proofing]], ready to bake
</gallery>