Cooking For Engineers

[Cucina Pro]

Why do recipes often call for mixing wet ingredients into dry? Also, cake recipes often call for alternating wet and dry ingredients. What is this about?

[SirShazar]

For cakes and pastries that are leavened with baking powder, the reaction that causes leavening starts when the baking powder gets wet (the baking soda and cream of tartar will react together in the presence of water and release carbon dioxide). Eventually, the reaction will run out and the leavening will stop.

Mixing the dry and wet ingredients in the last minute will ensure that your batter will rise to it's full potential. Mixing the wet into the dry is supposedly less messy.

I'm not sure what you mean by alternating wet and dry ingredients.

[GaryProtein]

For alternating wet and dry ingredients, some recipes will, for example, have you add flour then milk, then eggs, then sugar, etc.

I agree with you, SirShazar, that for the most part, all the dry ingredients should be combined, all the wet ingredients should combined, and finally all the wet and all the dry should be combined. This gives much better timing for the chemical reactions to take place and also usually makes for more thorughly mixed/dispersed ingredients.

[Guest]

OK, that makes sense.

The cake instructions I am talking about have you cream the butter and sugar, then add the flour mixture alternatively with the milk. Anyone know the reasoning behind this?

Thanks!

[SirShazar]

When you cream butter and sugar together, the sugar creates tiny air pockets in the butter that makes it less dense (it fluffs it up kinda like egg whites). If you just added all the liquid ingredients to the butter from the start you would get a denser cake.

Also worth mentioning, when you add the creamed butter mixture to the rest of the batter, be careful not to over mix as this will deflate the creamed butter.

[Cucina Pro]

AHA! I found the answer on joyofbaking.com:

The first addition of flour will be fully coated with the fat and does not form gluten, so it is a good idea to add the largest amount of flour in the first addition. When you add the liquid any uncoated flour will combine with the liquid and form gluten. Continue adding the flour and liquid alternately, making sure you mix on low speed just until blended. This will enable enough gluten to develop to provide structure but not enough to make a heavy and compact cake.