What does yeast do in pizza crust????????? Get Cooking Discuss What does yeast do in pizza crust????????? in the Brick Oven Cooking forums; I am a chemist, and my take is that the yeast puts a bunch of CO2 into the water of ...

[dower.bill]

I am a chemist, and my take is that the yeast puts a bunch of CO2 into the water of the dough, and CO2 is much less soluble in hot water than in room temp water. So when the dough gets hot, the CO2 turns to gas and inflates the crust. While the water is probably contributing to the expansion, I believe the CO2 is actually responsible for most of it. There are versions of waffles and pancakes that use yeast as a leavening agent with a similar process. You can see the 3rd edition of Joy of Cooking for some examples. Hope this helps.

Dr D.

[texassourdough]

It is actually even a bit more complex than that. Water contributes very minimally to the expansion for the dough temp "mostly" stays below the boiling point. The bulk of the expansion is, as you suggest, CO2 coming out of solution in the dough (okay water in the dough). But there is also a small amount of alcohol (and other light decomp products that are dissolved in the dough) that boils off and contributes to the expansion - at least in slow, overnight doughs.