Copyright © 2000 Sarah Phillips Sarah Phillips, Inc. All rights reserved.
Baked goods, leavened with baking soda, baking powder and the like are known as chemical leaveners (as opposed to yeast, a natural leavener). Their siblings are baker's ammonia and cream of tartar.
Chemical leaveners' can be purchased from the grocery store. They raise and aerate batters and dough by expanding the air bubbles created in them through mixing, beating, whipping, stirring and kneading. These millions of bubbles are trapped in the batter by the gluten structure formed and are enlarged by the leavener, either triggered by moisture and/or heat. In most cases you want to balance the leavening system to achieve a neutral pH.
What distinguishes one from the other has to do with the speed and timing of the leavener. Baking soda begins to create carbon dioxide gas when moistened. Double-acting baking powder (which most baking powders are these days) produces an initial set of gas bubbles when mixed with wet ingredients and then a second set when heated. The first reaction forms many small gas cells in the batter; the second reaction expands the bubbles to create a light texture. In the oven, heat not only assists these reactions, but also transforms the water in the recipe into steam that also contributes lift.
When carbon dioxide is released by either baking soda and/or baking powder, it first dissolves in the batter's liquid. When the liquid becomes saturated, the carbon dioxide begins to evolve into the air bubbles, causing them to expand. The bubbles continue to expand as long as the batter is not fully baked. When the batter sets into a firm structure during baking, the aeration is preserved which you see as the tiny air holes throughout the recipe.
BAKING POWDER, DOUBLE ACTING
Baking powder is basically a blend of acid (most commonly calcium acid phosphate, sodium aluminum sulfate or cream of tartar) and baking soda (alkali - sodium bicarbonate), creating carbon dioxide bubbles when both moistened and heated. It also contains an inert starch (i.e. corn starch) to act as a filler and prevent the components from reacting prematurely.
It is known as a double acting chemical leavener -- it begins release carbon dioxide as soon as it is moistened, and again when heated in the oven. (There are single acting baking powders, but are rarely used by home bakers). Always use double acting in recipes; it is virtually the only type available in grocery stores.
Baking powder does not need an acidic ingredient to release its leavening power, as baking soda does, because it contains its own; baking powder contains 30 percent baking soda (alkaline) and an acid, such as cream of tartar.
There are several different types of acids used in baking powder, each with a different pattern of producing gas bubbles, such as slow or fast, immediate or delayed. Most supermarket brands are double-acting, meaning it releases a portion of its gas in the cold batter/dough and quickly releases the remainder when heated in baking. Recipes using typical supermarket baking powder brands should be baked right after mixing because the acids they contain dissolve quickly. Some slow-release acids are only available to commercial manufacturers and restaurants, allowing batters to sit much longer before being baked or cooked without loss of leavening power. See discussion.
Some baking powders include sodium aluminum sulfate or aluminum, but there are aluminum-free ones that work just as well, which I prefer; powders made with aluminum lend an unpleasant flavor to delicately-flavored baked goods. (No health risks have ever been directly linked to its inclusion). Look for a brand like Rumford's at natural food stores and many supermarkets, which I highly recommend. There is also a low-sodium baking powder made by Featherweight, but it costs twice as much.
SARAH SAYS: Old-fashioned recipes! For one teaspoon SINGLE-ACTING baking powder: mix 1/2 teaspoon cream of tartar plus 1/4 teaspoon baking soda. Single-acting means that it will create gas quickly when moistened, so the batter must be cooked quickly or it will go flat. For double-acting baking powder, the kind commonly used in recipes and sold in grocery stores, there isn't any easy substitution. (There is not substitute for baking soda)
Baking Soda: Baking soda (bicarbonate of soda), another chemical leavener, is used when there is an acidic ingredient in the recipe. The acid might be hidden such as in honey and molasses. When baking soda comes in contact with an acidic ingredient and is moistened, the alkali/acid combination creates carbon dioxide (CO2), water and a neutral salt. It also renders a neutral, tasteless residue.
SARAH SAYS: Acidic ingredients include: applesauce, soured milk or buttermilk, honey, brown sugar, molasses, cream of tartar, lemon juice or vinegar, chocolate and cocoa powder (only regular cocoa, not Dutch-process).
If the level of baking soda is too high in the recipe, it creates soapy off-notes. If the level is too low, it will allow the acidic flavors to come through. Excess levels also result in over-browning
Baking soda is four times as strong as baking powder. The general rule is to use 1 to 1-1/4 teaspoons baking powder per cup of flour. On the other hand, baking soda should be added at 1/4 teaspoon per cup of flour.
Note: However, if you have a recipe that works and the above ratios are not followed, DO NOT adjust the recipe.
If you add an acidic ingredient to a recipe, adjust the leaveners.
Adding buttermilk (an acid) instead of milk: if the recipes uses 2 teaspoons baking powder, and you add 1/2 cup buttermilk, instead use 1 teaspoon baking powder + 1/4 teaspoon baking soda or 1 teaspoon baking powder = 1/2 teaspoon baking powder + 1/8 teaspoon baking soda
Note: Many times, other ingredients have to be changed as well when substituting ingredients, such as sugar, flour, fat, etc. It is not as simple as it looks.
- Baker's Ammonia (ammonium carbonate or ammonium bicarbonate ): Don't confuse this with ordinary household ammonia, which is poisonous. A type of baking powder, it yields a very light, airy product, but can impart an ammonia flavor to baked goods. It's best used in cookies, which are flat enough to allow all of the ammonia odor to dissipate during cooking. Northern Europeans still use it because it makes their springerle and gingerbread cookies very light and crisp. Look for it in German or Scandinavian markets, drug stores, baking supply stores, or a mail order catalogue. It comes either as lumps or powder. If it isn't powdered, crush it into a very fine powder with a mortar & pestle or a rolling pin.
- Cream of Tartar
QUESTION: Why is hot water used in some chocolate cakes?
SARAH SAYS: The use of hot water is utilized in chocolate cakes in two ways. Sometimes you will see the cocoa powder dissolved in warm water before it's added to the recipe. This helps dissolve it better for more cocoa flavor.
Then, there are recipes where the leavener is added to the hot water at the end of the recipe, ie: add the baking soda to the hot water, and add to the rest of the batter. That is done just for color. Baking soda is added not only to a recipe for leavening, but will also enhance color. When added to water, it expenses the leavener, but changes the pH of the recipe, enhancing/darkening the color of the cocoa powder in the recipe. If there is baking powder in the recipe, as well, that's what in fact, leavens the recipe, plus any left-over baking soda not expensed.
QUESTION: My muffins never bake very high. Can't I just double the leaveners in the recipe so they will?
SARAH SAYS: NO! Do not touch the leaveners because you'll create more problems if you do -- if you add more leaveners -- yes, the muffin will puff higher, but then the batter will spill over the sides of the pan and get all over your oven -- what a big mess (I've done it before when I accidentally doubled the baking powder in a recipe). What you are witnessing is an an excess of carbon dioxide spilling over because the muffin's gluten strands are not strong enough to hold them in before the muffin's structure sets.
Here's how it works: the leaveners start acting immediately when the muffin batter is put in the oven. They expand the air bubbles previously beaten or mixed into the batter and are held by the flour's gluten strands. At the end of baking, the flour's starches firmly set around the expanded air bubbles, the batter conforms to the shape of the baking pan and the recipe browns. When this happens, it is ready to come from the oven. (When you cut open a muffin, you'll see those little holes which are air bubbles). If you add too much baking powder and/or baking soda to the recipe, its gluten strands are not strong enough to hold in the excess carbon dioxide before the muffin's flour starches set, thus spilling over. P.S. If the muffin's structure sets first, then the recipe wouldn't be able to expand in the oven like a balloon.
BAKING POWDER VERSUS BAKING SODA
Baking Powder: fine white powder sold prepackaged Baking powder was not available until the 1860s in the United States.
Used in making quick-bread recipes, cakes, cookies and other related recipes.
Needs heat to be activated
Usually mixed in with the dry ingredients
If too much is used, it will make foods taste bitter and peppery in taste
Baking Soda: fine granular powder, sold in prepackaged form Baking soda was not available until the early 1800s in the United States.
Used in making quick-breads, cakes, cookies and other related baked foods
Needs an acid to be activated
Usually mixed in with the dry ingredients
The CO2 released from the baking soda merely expands the air bubbles previously formed in the batter or dough from whipping, beating or mixing, etc., making the baked good rise.
SARAH SAYS: Air bubbles are not created by the chemical leavener; they are simply enlarged by them, formed during creaming, mixing, kneading, beating, etc. The finer the air bubbles are beaten in, the finer the resulting baked good's texture will be. But, be careful -- sometimes too much beating, as in quick-breads, causes a tough recipe.
When I created 125 recipes for my Healthy Oven Baking Book, getting the right balance of the leaveners was the hardest task. Although there are rules for how much baking powder or soda you should add per cup of flour, these rules are really only guidelines. I would call my food scientist, Carol Lloyd, who consulted with me, and report: "I don't like the texture of my chocolate chip reduced-fat cookie or the color of the chocolate cake". She could often be heard saying: "Try adding 1/4 teaspoon baking soda" or with cookies, "Take out the baking powder, leave in the baking soda and see what happens". Creating recipes really takes a lot of trial and error, the knowledge of leaveners--and baking!! (With my White Cake Recipe, I baked it 100 times to get it right!).
QUESTION: I know you recommend buttermilk when making (homemade) cornbread. Is it also preferable to use buttermilk when using a commercial cornbread mix?
SARAH SAYS: I like to use buttermilk in recipe because it gives a nice mouthfeel, but I always balance the leaveners along with it.
It's best to use whatever the baking mix calls for. The leaveners in the recipe are formulated to activate based upon the pH of the ingredients. If the boxed mix said to add buttermilk, the batter's leaveners are formulated to counteract its acidity. The baking soda in the mix activates from the acid, provides carbon dioxide for leavening and at the same time neutralizes the flavor of the acidity in the batter giving you a nice taste and texture (too much acid in a batter would give you a craggy and uneven texture). If you added milk instead, the recipe would taste almost bitter or salty from the unneutralized baking soda in it unless it had baking powder instead.
THE BAKING POWDER AND BAKING SODA SWITCH-A-ROO:
QUESTION: Why do some cake recipes with Dutch-process cocoa powder use baking soda? I thought that only baking soda is supposed to be used in the presence of an acidic ingredient, such as natural cocoa powder, buttermilk and brown sugar.
SARAH SAYS: There is a lot of confusion about baking powder and baking soda and their use with Dutch-process or Natural Cocoa Powder and chocolate. It is a tough subject to grasp because there are so many opinions. Besides leavening, baking powder and/or baking soda contribute to texture, color and taste in a recipe.
I gained a lot of experience concerning leaveners and their use with cocoa powder and chocolate when I developed chocolate recipes for my Healthy Low-fat Baking Book and 2 mixes for my 12 flavor product-line, Healthy Oven (found nationwide for 10 years in grocery stores. Healthy Oven no longer being made). Two chocolate mixes, The Chocolate Muffin Mix and Chocolate Quick-Cake Mix, both made with Dutch process cocoa powder, were the toughest to create because of the contribution that the baking powder and baking soda made to the outcome.
Baking Soda: Using natural cocoa powder (an acid) in a recipe, calls for baking soda (an alkali).
Baking powder: Baking powder is used when there aren't any acidic ingredients in the recipe and helps to make its texture tenderer. Dutch-processed cocoa, also known as alkalized cocoa (nonacidic ingredient), is treated with a mild alkali, such as baking soda, to neutralize its acidity.
Baking powder is also found when used with chocolate, such as in the Thick Chocolate Fudge Brownie Recipe. Baking soda would give a harsh taste and would color the tops of the brownies a very dark brown, not very appealing.
Exceptions: With some recipes that have acidic ingredients, the use of baking powder is preferred instead of the customary baking soda. It is used in the recipe because it enhances flavor or retains the "tang" of an acidic ingredient, such as buttermilk.
Baking soda is used to produce the rich red color in some Red Velvet Cakes that call for Dutch-process cocoa. Vinegar and buttermilk, both acidic ingredients are added because the baking soda needs it to react. If the same recipe used baking powder, the cake would have a brown crumb color and probably taste bitter.
In my Healthy Oven Chocolate Chip Cookie Recipe where it has some brown sugar, an acidic ingredient, I use baking soda for leavening. But, it also helps the cookie bake faster, become chewy and moist in the absence of fat. Because it raises the pH in the recipe, it also brown betters.
Baking Soda and Baking Powder: Either baking soda and baking powder are used alone or in some recipes you'll see a combination of the two, such as in Tami's Classic Chocolate Cake Recipe. Recipes that call for both are probably using the baking soda to offset extra acidity in the batter (from ingredients like buttermilk or molasses) and to weaken the proteins in the flour. Omitting the baking soda from this recipe will alter its color or flavor and make it less tender.