Friday, November 6, 2009

Food Science Friday: Leavening Bread

We had a bread tasting workshop at my work this week featuring different breads made by my coworkers. We had a wonderful variety of textures, flavors and even methods of preparation. Today's food science fact is about leavening via yeast. We already talked about the difference between baking soda and baking powder on a past post as a means of chemical leavening. Biscuits, cakes, pancakes and quick breads like zucchini bread typically use baking powder and/or baking soda (which produces carbon dioxide gas through a chemical reaction) to leaven. In bread, yeast is often used to provide the leavening and create wonderful complex flavors for breads. The yeast is a living microorganism that ferments sugar to produce carbon dioxide and therefore leaven the bread. This biological process takes more time and is referred to as proofing or rising prior to going into the oven. The temperature and the humidity are two important factors that can affect the fermentation rate of the yeast and therefore how long it takes the bread to rise or proof.

So what did we taste this week and was it a quick bread or a yeast bread?

1. Avoca Brown Bread made by Helena

This hearty bread is a quick bread that uses baking powder and baking soda. Since it doesn’t use yeast, it is very quick and easy to make. Helena says it takes just 15 minutes to put together before baking.

2. No-Knead Bread made by me, Lauren

We have a whole blog post on this bread including the step-by-step here. This famous recipe uses 4 ingredients, including yeast, and is easy enough for a first time bread baker. It has very little steps but a very long fermentation time of 12 to 18 hours. This allows the yeast to ferment and develop the wonderful flavor. The high moisture dough and long rising time allows the gluten proteins to form a matrix without really kneading. By cooking the high moisture dough in a sealed pot, this simulates the professional steam injected ovens that make wonderful crusty bread. The steam bake is what allows the beautiful crust to form. The results are phenomenal.

3. Cinnamon rolls made by Adam.

These homemade sweet rolls had a wonderful texture and flavor. These are also yeast raised. Adam served them with frosting but they were eaten before I could take a photo! You may have had cinnamon rolls in a can from the supermarket. Those cinnamon rolls don't use yeast but instead use a baking powder/ soda to leaven. You will notice a different flavor and texture than the yeast raised ones.

4. French-Style Bread by Adam

Adam also shared two loaves of lovely white bread- great alone or with butter and jam or for a sandwich. These are also yeast raised loaves.

5. German buttermilk bread by Thomas

These two versions of dense and hearty bread are great with butter and a bit of salt. Their texture was somewhat similar to Helena's avoca bread but again this was a yeast raised bread.

6. Challah bread made by Rachel

This traditional Jewish braided loaf of bread was almost too beautiful to eat! This was a beautiful yeast raised bread that is plaited into the traditional braid- just gorgeous!

So as you can see, it was a bountiful feast of bread. I have the recipe for each loaf. Please comment or email us if you would like us to send it to you!