Today, I’m going to explore leavening agents: baking soda, baking powder, yeast, rapid-rise yeast, etc.
I suspect the hidden cause of many failed recipes are bad ingredients. Not bad as in ‘spoiled’ or ‘expired.’ Bad as in low-quality or the wrong ingredient. When I started making bread, I had some disasters. One loaf even the ducks at the pond wouldn’t eat. This was the same loaf that had me wondering how a loaf of bread could possibly weigh MORE than the individual ingredients! I can’t remember what I did, but looking back I’m betting I messed up with the yeast.
High-quality and the correct ingredients are the difference between a delicious recipe and a…well, disaster. Or at least a low-quality product. Hence this ongoing series of posts covering the fundamentals of baking. If you’re interested, you can hop on over to the ‘Ingredients,’ ‘Substitutes,’ ‘Cooking 101,’ and ‘Cooking 201’ pages if you want. And…on to business.
First of all, let’s deal with the terms: leavening, fermenting, rising agents.
• Leavening (leavening agent): to lighten. A substance used to produce fermentation in dough or batter. Aka: the substance that causes the dough or batter to rise. This includes yeast, chemical, and mechanical leaveners.
• Fermentation: the process of yeast converting sugars to carbon dioxide and alcohol. The carbon dioxide is what makes it rise.
• Rising agents: synonym for leavening.
-To make it simple: everything that “rises” uses leaveners. Only yeast products (some bakery items, yeast bread, etc.) undergo fermentation.
If you’re interested and want more details, I have an article “Why Does Bread Rise?” that includes a short YouTube video that is really great at explaining it.
Now on to the ingredients we actually work with!
- Double-acting baking powder: compound leavener. Includes the baking soda, but also has a moisture control/stabilizer (usually cornstarch) and an acid. It reacts twice: first when moistened with the liquids in the recipe and second when heat is applied in the oven. This is the one you will most commonly use.
- Single-acting baking powder: reacts only once (with the liquid ingredients). No longer commercially available, but preferred by some bakers.
- Note: there technically are more types of baking powders based on the acid used, but as double-acting baking powder is what is “normally” called for, I’m not going to get into the chemistry.
Baking soda: bicarbonate of soda. Alkali. Creates carbon dioxide gas when combined with acidic ingredients (such as buttermilk, yogurt, sour cream, citrus, vinegar, cream of tarter, brown sugar, molasses, chocolate, natural cocoa powder, etc.). If a recipe calls only for baking soda, there MUST be an acid ingredient to activate it. Must be baked immediately after mixing.
Cream of tarter: naturally fermented leavener found in the bottom of wine barrels. Combined with baking soda to make single-acting baking powder. Will keep indefinitely if stored in airtight, cool, dry area.
Self-rising flour: flour that already has the chemical leavening agent (baking powder) and salt already added to it.
Yeast: single-celled microorganisms in the fungus family. Yeast is activated by moisture, warmth, air, and something to feed on. There are multiple strains of yeast used for various things (baking, brewing beer, wine production, etc.). The yeasts below are all used for various baking purposes. Note that the main difference is in moisture content, and that they are considered interchangeable WITH allowances for liquid content in recipe and temperature.
- Active dry yeast: most common type of yeast.
- Sold in .25-ounce packets (three in a strip) or in jars. Brownish granules.
- Store in tightly covered container in refrigerator. [Note: Some sources say you can store in the freezer for up to a decade.
- Use: Needs warm water to be activated (105°-115°F). This yeast is more sensitive to thermal shock. Let come to room temperature before proofing. And make sure water is no hotter than 120°. Some recipes may not call for you to proof the yeast, but I (and many other bakers) always do.
- Compressed fresh cake yeast (aka: cake yeast, compressed yeast): this is becoming increasingly hard to find as dry yeasts replace it (stores prefer dry as it has greater shelf-life).
- Sold as small foil-wrapped cubes at stores. 1 lb. blocks might be available at local bakeries. Highly perishable. Tan-gray color.
- Store at around 30° F. Will stay fresh for approximately 2 weeks wrapped in plastic.
- Use: Dissolve in tepid (80°-95°F) liquid before adding to dry ingredients. Some bakers swear that this yeast makes a serious difference and is better than dry yeast. (I personally haven’t tried it).
- Instant dried yeast (aka: instant yeast, quick-rise yeast, rapid-rise yeast): lower percentage moisture and smaller particles than active dry yeast.
- Sold: one-pound vacuum-packed bags. Also sold in .25-ounce packets (three in a strip) or in jars.
- Store in airtight container in freezer.
- Use: Can be added directly to dough; does not require rehydration. Allows dough to be baked without initial rising time. In other words, you can shape the dough into loaves and simply allow it to rise once.
- There is an ongoing debate over whether ‘rapid-rise’ and ‘instant’ yeast are the same thing. Fleischmann’s flat out says there is no difference. Since they produce most of what I buy, I’m going to take their word.
- There is another debate over whether active dry or rapid-rise is better. Most cooks prefer active dry. The extra rise is needed for great bread. A few disagree.
- Bread machine yeast: finely granulated and coated with special buffer. Allows for it to be mixed directly into other dry ingredients before liquid is added and less sensitive to temperature changes. Don’t use unless you’re using a bread machine. (Don’t use that…please? Homemade is better).
- Deactivated yeast: not interchangeable with other yeasts. It is a dead yeast that technically doesn’t leaven. It is used with pizza and some pan bread doughs. It increases the “extensibility” of the dough. [Update: debate exists whether this is actually deactivated, since it obviously still has an effect on dough plus debate exists whether the additives have any value in making pizza. While deactivated yeast might not be the ‘best’ term, it is widely understood.]
- Use of steam and air to leaven is almost universal in cooking and baking. This is simply air that is naturally captured in the batter during the mixing process that expands while the product is cooking.
- Mechanical leavening: the process of ‘beating’ or ‘creaming’ air into a product. You cream together butter and sugar for cookies and sugar and cream cheese for cheesecakes. This incorporates tiny air bubbles into the mixture. Whisking creates foam by adding air into the ingredients. Beating eggs is also incorporating air.