Many recipes call for yeast as an ingredient, but some people either can't or won't eat it because of allergies or health issues. Find out if you can substitute other ingredients for yeast, and more importantly, whether these substitutes will result in a pleasing bread or cake.
How Yeast Works
Yeast is a single-celled fungi used to give texture to breads, pastries, muffins, pancakes, waffles, and cakes. The most common type of yeast you buy in the store is called active dry yeast. The cells have been dehydrated for long storage. When the yeast is added to a dough or batter, it rehydrates, then grows and multiplies and produces carbon dioxide. This gas is trapped by protein and carbohydrate networks in doughs and batters and forces the mixture to rise to give the finished product its characteristic texture.
You can sometimes find cake yeast in stores and coops. This product is made of live yeast cells, compressed together to form a block or square. It must be stored in the refrigerator and is a perishable product.
When Not to Substitute
There is really no substitute for yeast in classic kneaded bread doughs. The structure of gluten protein in those products is very strong, and substitutes such as egg whites, baking powder, or baking soda are not powerful enough to stretch that protein network. Yeast performs another function in bread doughs; it "kneads" the dough at a microscopic level as it grows, improving the texture of the bread.
When You Can Substitute
There are some substitutes for yeast that you can use in recipes such as batter breads, pancakes, pizza dough, and cakes. The texture of the finished product will not be quite the same if yeast is not used. The crumb may be more coarse, or the product may not rise as high or be as fluffy or light. But the cake, or pizza crust, or cupcake will still be acceptable.
When substituting other leaveners for yeast, don't look at the amount of yeast called for. The substitution will depend on the amount of flour used in the recipe.
Baking soda (sodium bicarbonate) is an alkaline ingredient that produces carbon dioxide (CO2) when it is combined with an acidic ingredient such as lemon juice or buttermilk. The CO2 stretches the gluten and carbohydrate network in batters as the mixture bakes so it rises. Baking soda also increases the pH of a batter, which keeps the finished product tender.
How to Swap
Baking soda is best used as a substitute in more delicate recipes such as pancakes, cakes, light batter breads, and cupcakes. Do not use it as a substitute in kneaded breads, hearty batter breads, pizza dough, or cakes that use fruits and nuts.
About 1/4 teaspoon of baking soda, plus an equivalent amount of acid, is used to leaven 1 cup of flour in most recipes. If, for instance, a recipe calls for 2 cups of flour, substitute 1/2 teaspoon baking soda plus 1/2 teaspoon of vinegar or lemon juice for the yeast. You will need more baking soda if you are making a recipe with whole grains; add about 1/8 teaspoon more per cup of flour.
Differences You May Notice
The bread or cake made with baking soda will have a different texture than one made with yeast, with larger air holes in the crumb. Baked goods made with baking soda tend to brown less than goods made with baking powder or yeast. You can sprinkle the dough or batter with a bit of sugar or brush it lightly with some milk before it goes into the oven to increase browning. Remember that if there is not enough acid in the recipe, the finished product can taste slightly soapy because baking soda is alkaline. So make sure that you add equal amounts of acid and baking soda to the recipe.
Baking powder is another acceptable yeast substitute. This ingredient is a combination of baking soda and an acid. There are two types of baking powder: single acting and double acting. The single acting powder starts producing CO2 as soon as it is comes into contact with liquid. The double acting type produces CO2 with liquid and in the heat of the oven.
Remember that baking powder can be made with two kinds of acid: calcium phosphate or aluminum phosphate. Some people can sense a bitter aftertaste in baked goods made with aluminum phosphate baking powder. Read the label of the baking powder you purchase to see which type is used.
When to Use
Baking powder can be used as a yeast substitute in recipes such as cakes, pizza dough, cupcakes, pancakes, muffins, and batter breads. Do not use baking powder in kneaded yeast breads.
To substitute baking powder for yeast in recipes, use about 1 to 1-1/4 teaspoons of baking powder for every cup of flour. If the recipe calls for whole grain flour such as whole wheat or rye flour, add another 1/4 teaspoon of baking powder per cup. Baking powder has an expiration date; check the date before you use it.
Too much baking powder will make a food bitter so don't add too much. And if a recipe calls for a lot of an acidic ingredient, such as in a lemon bread or lemon cake, it's a good idea to add a pinch of baking soda in addition to the baking powder to help balance the pH of the product. These products made with baking powder will have a more open crumb and coarse texture than one made with yeast.
Eggs or Egg Whites
Beaten eggs or egg whites can be used as leavening in some recipes. This ingredient works best in cakes, pancakes, and batter breads and will not work in kneaded yeast breads. While the eggs or egg whites are beaten, the proteins denature. That means they unwind and form a network that traps air. In a batter that air expands in the oven and the bread or cake rises.
How to Switch
Beaten eggs and egg whites can be used instead of yeast as leavening in batter breads, cakes, cupcakes, muffins, and pancakes.
If a recipe calls for eggs or egg whites, use them as a substitute for yeast. Beat them separately from the other ingredients with an electric mixer. Beat whole eggs for about 5 minutes until they are light and lemon colored. Carefully add the remaining ingredients to keep as much air in the batter as possible. Then get the batter into the pan and the oven quickly.
To use egg whites for leavening:
Separate the yolks from the whites, being careful not to let any yolk into the white, which will reduce foaming.
Put the whites in a clean bowl and beat with an electric mixer, adding some of the sugar the recipe calls for to stabilize the foam.
Combine the remaining ingredients, then carefully fold in the egg whites.
Pour or spoon the batter into the pan and bake.
Baked goods made with egg whites as a leavener tend to be more fragile than goods made with other leaveners. The cake or bread may also be a bit drier with a finer texture, but there shouldn't be any change in taste.
Sourdough starter is made by combining yeast with flour and water. The mixture stands for days at room temperature. The yeast uses the flour as food. It grows and produces CO2 and acid over time, which gives sourdough products their characteristic sour flavor.
Use Grapes Instead of Yeast
You can make sourdough starter without commercial yeast by using grapes, which carry wild yeast on their skins, although this technique is not guaranteed.
Put a 1/2 pound bunch of unwashed, organic grapes or wild grapes into a mixture of 1-1/2 cups flour and 2 cups water.
Cover and let stand at room temperature for 4 to 7 days, stirring in a few spoonfuls of water and flour every day.
If it works, the mixture will begin bubbling.
You can then strain out the grapes and refrigerate the starter. It can be used in sourdough bread and pancake recipes. Use about half of the starter, then add more flour and water to replenish it. Store covered in the fridge.
Breads and other baked goods made with sourdough starter will have almost the same texture as those products made with plain yeast, but the texture will be finer. The flavor of sourdough goods will be more acidic than those made with regular yeast.
Tips on Working With Yeast Substitutes
Whenever you use baking powder, baking soda, or beaten eggs or egg whites as a substitute for yeast, get the dough or batter into the oven quickly. Cakes, cupcakes, and batter breads are delicate and the CO2 trapped in their structures can escape if they are left to stand too long. Bake them quickly for best results.
When you successfully update a yeast recipe using another leavening, be sure to write down the amounts you used and when you added the leavening to the recipe.
If a substitute doesn't work at first, don't give up. Look at the product. Is it not brown enough? Brush with milk or a sugar solution before baking next time. Is it too sour? Use baking powder instead of baking soda next time. Did it not rise enough? Increase the amount of leavener the next time you make it.
Successful Yeast Swaps
If you can't or won't eat baked goods made with yeast, you can substitute other leaveners as long as you aren't making a kneaded bread recipe. Armed with this knowledge, you can experiment with these leaveners to get the result you want. And remember that part of the fun of baking is experimenting and enjoying your successes.