Bread ingredients–leavening

 

Bread ingredients–Leavening

When someone says “leavening,” everyone thinks of yeast. That’s because yeast gets all the press. It is a living plant, which can be caught wild (next post), or purchased in an envelope or cube, depending whether it is dry yeast or cake yeast.

Yeast can be a post on its own. I’ll be going over it a bit later, after we look at other leavening.

Air

It’s all around, and gets into batters and doughs through stirring, beating, and kneading. Angel food cake is an excellent example. It can take up to a dozen egg whites, whipped to stiff peaks, to raise that cake. In whipping the egg whites, air is incorporated into them. Gently folded into batter then baked, the air expands in the hot oven, the egg solidifies, and the cake is raised. Beaten egg whites alone usually only work for something really light, like angel cake.

Baking powder

Baking powder is a combination of baking soda, which is alkaline, and an acid, usually cream of tartar, a by-product of the wine industry. A little cornstarch is added as a buffer, so they don’t react with each other. This will make a single-acting baking powder:

1 part cornstarch

2 parts baking soda

4 parts cream of tartar

Sift these together 3-4 times, store in a tightly covered container.

Baking soda, bicarbonate of soda, is a by-product of the salt making industry. It is less soluble than sodium chloride, and reacts with acids to release carbon dioxide. With a single-acting baking powder, heat needs to be applied for the reaction to set. This differs from double-acting baking powder, which has a bit of alum in it. I’m researching a recipe for that, but haven’t even found one online. Double acting baking powder will react with itself in the heat of the oven, but also reacts when mixed with liquids in the batter/dough. Put a bit into milk, and watch the bubbles rise.

The next post will be more than you really want to know about yeast.