You can use baking soda and vinegar instead of an egg at a ratio of 1 teaspoon of baking soda mixed with 1 tablespoon of vinegar per egg. That is the leavening egg replacement: it does not bind or moisten the way an egg does, but it produces carbon dioxide gas when the acid (vinegar) meets the alkali (baking soda), and that gas lifts the batter the way a beaten egg would. It is the egg substitute to use in light, airy bakes — a sponge cake, a cupcake, a quick bread — where the egg's main job is lift and the recipe has other ingredients providing moisture and binding. It is not a substitute in recipes where the egg provides structure or richness, and this page explains exactly where that line falls.

Baking soda and vinegar is the oldest egg substitute in the book, and it is the one that surprises people most, because it contains no egg-like ingredient at all — just a chemical reaction. The reaction is the same one that makes a volcano in a school science experiment, and in a batter it does the same thing on a smaller scale: the bubbles lift the crumb and make it light. A cupcake made with baking soda and vinegar instead of eggs is light and fluffy, with a fine crumb and no hint of vinegar — the vinegar's flavour disappears during baking, because the acid is neutralised by the soda. The key is to mix the soda and vinegar together and add them to the batter immediately, because the reaction starts at once and the gas escapes if you wait.

The ratio, in a table

The table below converts eggs to baking soda and vinegar for the amounts you are most likely to meet. The rule is always the same: 1 teaspoon of baking soda plus 1 tablespoon of vinegar per egg. Use white vinegar or apple cider vinegar — both work, and the flavour disappears during baking.

Eggs called for Baking soda Vinegar Notes
1 egg 1 teaspoon 1 tablespoon Mix and add immediately
2 eggs 2 teaspoons 2 tablespoons
3 eggs 1 tablespoon 3 tablespoons At the limit
4 eggs 1 tablespoon + 1 teaspoon 4 tablespoons (1/4 cup) Not recommended
5 eggs 1 tablespoon + 2 teaspoons 5 tablespoons Not recommended
6 eggs 2 tablespoons 6 tablespoons Not recommended

One large egg weighs about 50 grams, and the baking soda and vinegar mixture — 1 teaspoon of baking soda (about 5 grams) plus 1 tablespoon of vinegar (15 grams) — weighs about 20 grams, which is much lighter than an egg. If you are weighing ingredients, that difference matters: the batter will be lighter and drier than the egg version, because the mixture adds lift but almost no moisture. That is why the swap works best in recipes that are already moist, and why it is usually combined with another replacer — a tablespoon of applesauce or yogurt per egg — to supply the moisture the soda and vinegar cannot.

Worked examples

Example 1: A light cupcake without eggs

A cupcake recipe calls for 1 egg. Replace it with 1 teaspoon of baking soda mixed with 1 tablespoon of white vinegar, added to the batter just before baking. The cupcakes will be light and fluffy, with a fine crumb and no vinegar taste — the acid is neutralised during baking. This is the best first recipe to try the swap in, because cupcakes are small, bake quickly, and the leavening effect is exactly what they need. Work quickly once the soda and vinegar are mixed: the gas starts escaping immediately, and a batter that sits for ten minutes will lose its lift.

Example 2: A vegan sponge cake

A sponge cake recipe calls for 2 eggs, and you are making it vegan. Replace them with 2 teaspoons of baking soda mixed with 2 tablespoons of vinegar, and add 2 tablespoons of applesauce for moisture. The cake will be light and airy, with a fine crumb — the soda and vinegar provide the lift, and the applesauce provides the moisture that the soda and vinegar cannot. This combination is the classic vegan sponge technique, and it is the closest a plant-based substitute comes to mimicking a beaten egg's lift.

Example 3: A quick bread with a better rise

A quick bread recipe calls for 1 egg, and the bread always comes out a little dense. Replace the egg with 1 teaspoon of baking soda and 1 tablespoon of vinegar, and the bread will rise better than the egg version — the extra leavening gives it a lighter crumb. This is the swap to use when the egg's leavening matters more than its binding: the bread will be lighter, though it will also be slightly drier, so add a tablespoon of milk or water to compensate.

What changes in the result

Three things change when you swap baking soda and vinegar for an egg. First, the lift: the bake will be lighter and airier than the egg version, because the chemical reaction produces more gas than an egg's leavening. Second, the moisture: the bake will be drier, because the mixture adds almost no moisture — 20 grams compared with an egg's 50 grams. That is why the swap is often combined with a moist replacer like applesauce or yogurt. Third, the flavour: nothing, if the ratio is right. The vinegar's flavour disappears during baking, because the acid is neutralised by the soda. If the ratio is wrong — too much vinegar — the bake will taste sour; if there is too much soda, it will taste soapy and bitter. Measure carefully.

The practical consequence is that baking soda and vinegar is a leavening replacer, not a general egg replacer. It works in light, airy bakes where the egg's main job is lift and the recipe has other ingredients providing moisture and binding. It does not work on its own in a dense, moist bake, where the egg's moisture and binding are essential — for those, combine it with applesauce or yogurt, or use a different replacer entirely.

When not to substitute

Do not use baking soda and vinegar in meringues, custards, angel food cake, or any recipe where egg is the main structure. The mixture cannot whip, set or bind — it can only lift. Do not use it in a recipe that calls for more than three eggs — beyond that, the recipe relies too heavily on eggs, and the mixture cannot carry it. Do not use it on its own in a dry recipe, because the bake will be too dry; combine it with a moist replacer. Do not let the batter sit after adding the mixture, because the gas escapes and the lift is lost. And do not use it in a recipe that already contains a lot of baking soda — the extra soda will make the bake taste soapy and bitter. Check the recipe's leavening before adding more.

One more caution: the vinegar must be mixed with the soda, not added separately. If you add the vinegar to the batter and the soda to the flour, the reaction will happen unevenly and the lift will be patchy. Mix them together in a small bowl — it will fizz immediately — and stir the fizzing mixture into the batter at once, then get the batter into the oven without delay.

Frequently asked questions

How much baking soda and vinegar do I use instead of 1 egg?

Use 1 teaspoon of baking soda mixed with 1 tablespoon of vinegar per egg. Mix them together — they will fizz immediately — and stir the mixture into the batter at once, then bake immediately. Use white vinegar or apple cider vinegar. Do not use it to replace more than three eggs in a single recipe.

Will my cake taste like vinegar?

No, if the ratio is right. The vinegar's acid is neutralised by the baking soda during the reaction, and the flavour disappears during baking. If the cake tastes sour, you used too much vinegar; if it tastes soapy or bitter, you used too much baking soda. Measure both carefully, and the flavour will be neutral.

Can I use baking soda and vinegar in a sponge cake?

Yes — it is one of the best egg replacements for a sponge cake, because the egg's main job in a sponge is lift, and the soda-vinegar reaction provides lift. Combine it with a tablespoon of applesauce or yogurt per egg for moisture, because the mixture on its own is dry. The cake will be light and airy, though it will not have the rich flavour that eggs give a sponge.

What is the difference between baking soda and baking powder?

Baking soda is a pure alkali that needs an acid — vinegar, lemon juice, buttermilk, yogurt — to produce gas. Baking powder is baking soda plus its own acid (cream of tartar), so it produces gas with just moisture and heat. The soda-vinegar mixture is essentially a homemade baking powder, made fresh in the bowl. Do not substitute baking powder for the mixture without adjusting the amount — baking powder is weaker, so you would need more of it.

Can I use lemon juice instead of vinegar?

Yes. Lemon juice is also an acid, and it reacts with baking soda the same way vinegar does. Use 1 tablespoon of lemon juice per teaspoon of baking soda, the same as vinegar. The lemon flavour will be barely noticeable in the finished bake, and it can be pleasant in a lemon cake. Do not use a non-acidic liquid — water will not react with baking soda at all.

How many eggs can I replace with baking soda and vinegar?

Up to three, and ideally one or two. Beyond three eggs, the recipe relies too heavily on eggs for structure, and the mixture cannot provide it. The mixture is also dry, so for more than one egg, combine it with a moist replacer like applesauce or yogurt to keep the batter from drying out.

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