Baking is both an art and a science. Understanding the ingredients you use and how they interact is key to baking success. Two of the most commonly used leavening agents in baking are baking powder and baking soda. Though they seem similar and are often used for the same purpose, there are important differences between these two pantry staples.
If you've ever been confused about baking soda vs. baking powder, you're not alone! Many home bakers use these ingredients interchangeably, not realizing that improper substitutions can lead to baking flops.
Read on to learn how baking soda and baking powder work, discuss their differences and provide tips for choosing and using them correctly.
What Are Leavening Agents and How Do They Work?
Leavening agents are ingredients that cause batters and doughs to rise during baking. The gas bubbles produced by leavening agents expand when heated, creating air pockets in the baked goods. This results in a light and airy texture compared to dense, heavy baked goods made without leavening.
The main types of leavening agents are:
- Chemical leaveners - Baking soda and baking powder
- Biological leaveners - Yeast
- Mechanical leaveners - Whipped egg whites, whipped cream
Chemical leaveners like baking soda and baking powder produce gas through acid-base reactions.
Biological leaveners like yeast produce gas via fermentation.
Mechanical leaveners incorporate air into a batter through physical agitation.
Understanding how leaveners work allows you to choose the right one for your baking needs.
Baking Soda
Baking soda, also known as sodium bicarbonate or bicarbonate of soda, is a chemical leavening agent. It is a pure alkali compound that creates carbon dioxide gas when combined with an acid and a liquid.
Acidic ingredients activate baking soda, causing it to rapidly produce bubbles. Examples of acidic ingredients that react with baking soda include:
- Buttermilk
- Honey
- Molasses
- Natural cocoa powder
- Lemon juice
- Vinegar
Because baking soda begins reacting as soon as it contacts the wet ingredients, recipes leavened with baking soda should be assembled quickly and baked immediately. Batters and doughs with baking soda have low bench tolerance - meaning they can't be stored for long before baking.
Too much baking soda can give baked goods a soapy or metallic taste. As a general rule, use 1/4 teaspoon of baking soda per 1 cup of flour. Recipes with baking soda often call for additional ingredients like brown sugar, chocolate, or lemon juice to provide enough acidity for proper rising and balance the baking soda's alkaline taste.
Baking soda is ideal for recipes that already contain acidic ingredients like buttermilk pancakes, chocolate cookies, and lemon loaf cake. It promotes browning and helps retain moisture in baked goods.
Baking Powder
Unlike baking soda, baking powder is a complete leavening agent, containing an acid as well as a base.
Baking powder contains:
- Baking soda (alkaline base)
- An acid, such as cream of tartar or calcium acid phosphate
- A neutralizing agent like cornstarch
The acid and base are in the ideal proportions to react when liquid is added, producing carbon dioxide bubbles. No additional acid ingredients are required.
Most baking powder today is "double acting" - producing bubbles at two stages:
- When combined with liquid
- Again at high temperatures during baking
This gives batters and doughs with baking powder good bench tolerance - they can be stored in the refrigerator before baking with minimal rising.
Baking powder is used in recipes that don't contain much acidity, like biscuits, pancakes, scones, and some cakes and cookies. It can also be combined with baking soda when extra lift is needed.
Too much baking powder can impart a bitter, soapy taste. As a general rule, use 1 teaspoon of baking powder per 1 cup of flour.
Key Differences Between Baking Soda and Baking Powder
Now that you understand how each ingredient works individually, let's summarize the main differences:
- Composition: Baking soda is pure sodium bicarbonate. Baking powder contains sodium bicarbonate, an acid, and a neutralizing agent.
- Reactivity: Baking soda must combine with acid and liquid to produce bubbles. Baking powder just needs liquid to react.
- Speed: Baking soda reacts instantly, while baking powder reacts in two stages (upon mixing, and again during baking).
- Taste: Baking soda is alkaline with a slightly metallic taste. Baking powder is neutral in taste.
- Uses: Baking soda is used in recipes with existing acidity. Baking powder can be used alone with no acidic ingredients.
- Browning: Baking soda promotes browning and spread. Baking powder minimally affects browning.
- Bench tolerance: Batters with baking soda must be baked immediately. Those with baking powder can be refrigerated.
Can Baking Soda and Baking Powder Be Substituted for Each Other?
While baking soda and baking powder cannot be substituted equally, you can modify recipes to allow switching between the two.
To substitute baking powder for baking soda:
- Use 3 times as much baking powder as baking soda (for equal leavening power)
- Baking powder on its own may impart a bitter taste
To substitute baking soda for baking powder:
- Use 1/4 as much baking soda as baking powder
- Ensure the recipe contains an acidic ingredient like buttermilk, yogurt, honey, etc. to react with the baking soda
- Add cream of tartar or lemon juice to provide acidity if needed
When baking soda and baking powder are used together, it provides extra lift while retaining flavor from acidic ingredients. Baking soda also helps with browning and spread.
Storing and Testing Baking Soda and Baking Powder
While baking soda and baking powder have indefinite shelf lives, they lose potency over time. To test freshness:
For baking soda:
- Add 1/4 teaspoon to a small bowl with 1 teaspoon vinegar
- It should fizz and bubble immediately if fresh
For baking powder:
- Add 1/2 teaspoon to 1 tablespoon hot water
- It should bubble right away if still active
For best results, replace baking soda and baking powder every 6 months once opened. Store in cool, dry areas away from heat and moisture.
FAQ
Why do some recipes use both baking soda and baking powder?
Using both provides extra lift and leavening power. Baking soda also balances and retains flavor from acidic ingredients while allowing baking powder to focus on rising.
Which is better in cookies, baking soda or baking powder?
Baking soda helps cookies spread out and become crispy on the edges. Baking powder makes them thicker with a more cake-like texture. Using both creates a balance of spread and lift.
Can I make my own baking powder by mixing baking soda and cream of tartar?
Yes! Use 2 parts cream of tartar to 1 part baking soda. Add a little cornstarch to keep it dry.
What can I substitute if I don't have baking powder or baking soda?
For baking powder, try baking soda plus an acid-like cream of tartar or lemon juice. For both, use self-rising flour or whipped egg whites.
Conclusion
Baking soda and baking powder are both invaluable leavening agents with unique properties.
Understand how each one works individually, as well as how to properly substitute one for the other.
Remember - mastering the science of baking helps remove the luck and guesswork.