So You've Run Out of Baking Powder. What Now?

It’s an all too familiar scene - you find yourself with a little spare time at the weekend and decide to rustle up a batch of pancakes or a quick sponge cake, only to find one of your key ingredients is missing from the cupboard. In situations like these, it's useful to be aware of a few key baking substitutes, like using honey instead of sugar, or oil instead of butter. After all, they can mean the difference between cake and no cake.

Baking powder, in particular, is one of those ingredients you can easily run out of without noticing, but when it comes to baking, it does a very particular job, and can be difficult to replace. Most baked goods need a leavening agent to make them rise, and if you leave it out, your cake or your cookies will fall flat. 

Baking powder makes dough rise because it contains both a base and an acid in dried form. When the powder mixes with the wet ingredients in the dough, the acid rehydrates and reacts with the base, producing carbon dioxide gas, which gets inside the dough and puffs it up. 

Some people make the mistake of swapping baking powder for baking soda, but because baking soda contains the base element only, it won’t do anything unless added alongside another, acidic ingredient. Any replacement for baking powder must involve these two key elements - a base and an acid - for the reaction to take place. If you do find yourself without baking powder, read on for a list of substitutes that work.

Buttermilk and Baking Soda

Buttermilk is a fermented dairy product, similar in flavour to yoghurt. It is usually made by adding bacterial cultures to milk which break the sugars down into acids, giving buttermilk its distinctive sour, slightly tangy flavour, and also making it a good choice for activating baking soda. 

For every 1 teaspoon of baking powder in your recipe, you should add ¼ teaspoon of baking soda to your dry ingredients and ½ cup of buttermilk to the wet ingredients. You will also need to reduce the other wet ingredients or the buttermilk will make your mixture too wet. For best results, take away the same amount of liquids you put in, so if you add ½ cup of buttermilk, you should reduce the other wet ingredients by ½ cup too. This does mean buttermilk and baking soda aren’t the best option for recipes that don’t contain much liquid to begin with, as you can’t reduce something that wasn’t there in the first place.

Yogurt + Baking Soda

Like buttermilk, yoghurt is a fermented milk product, made acidic by the fermentation process. This makes it another ingredient that can be added to baking soda to make your dough rise. Use in the same quantities as buttermilk - ¼ teaspoon of baking soda and ½ cup of buttermilk for every teaspoon of baking powder in the recipe - and reduce the wet ingredients in proportion to the amount of yoghurt added. This does have the same issue as buttermilk, however, and works better in recipes that call for plenty of wet ingredients. 

Sour Milk + Baking Soda

If you don’t have any buttermilk or yoghurt, it could be worth checking the milk in your refrigerator to see if it has started to go sour. If so, you’re in luck - milk that has just started to go sour has begun the fermentation process, and will contain lactic acid, which you can use to activate baking soda. 

It is important to note that the sort of milk you need is only just beginning to go sour, not curdled or spoiled, but if do happen to have milk that is just that right level of sourness, you can add it in the same proportions as buttermilk and yoghurt, again remembering to reduce the other wet ingredients as necessary.

Lemon Juice + Baking Soda

Lemon juice is extremely high in citric acid, so you only need a small amount to activate the baking soda. This makes it a good option for recipes with predominantly dry ingredients, as it won’t make your mix too wet. However, lemon does have a very strong flavour, so this is best used in recipes that don’t call for very much baking powder, unless you’re making something that would go well with a hint of lemon. 

For every teaspoon of baking powder in your recipe, add ¼ teaspoon of baking soda to the dry ingredients and ½ teaspoon of lemon juice to the wet ingredients. You don’t need to reduce the wet ingredients for this method, as you are only adding a very small amount. 

Vinegar + Baking Soda

Vinegar is another highly acidic ingredient, and in fact, vinegar with baking soda is one of the most common substitutes for baking powder. It is something most people already have in their kitchen cupboards, and only needs to be added in small amounts, so you don’t have to worry about reducing your wet ingredients to accommodate it. 

White vinegar is the best choice, as it has the most neutral flavour, and won’t colour the mix. If you don’t have any white vinegar handy, rice vinegar or apple cider vinegar also work well. Use in the same quantities you would lemon juice, substituting ¼ teaspoon of baking soda and ½ teaspoon of lemon juice for every teaspoon of baking powder in the recipe.

Molasses + Baking Soda

Despite its sweet flavour, molasses actually contains enough acid to cause a reaction with baking soda, and can be used at a ratio of ¼ cup of molasses and ¼ teaspoon of baking soda to replace every teaspoon of baking soda. Here again, you will need to reduce the wet ingredients in proportion with the amount of molasses added, and you should also consider removing some sugar from the recipe, as molasses is very sweet.

Cream of Tartar + Baking Soda

Cream of tartar is an acidic white powder created as a by-product of winemaking, and mixed with baking soda, it’s almost an exact match for baking powder. It doesn’t have a strong flavour, and because you only need a little for a reaction to occur, you don’t need to worry about altering any other ingredients. For every teaspoon of baking powder in your recipe, substitute ¼ teaspoon of baking soda and ½ teaspoon of cream of tartar.

Whipped Egg Whites

So far, all of our baking powder substitutes have required the use of baking soda, but if you don’t have that either, you’ll need to get air into the mix a different way. One way of achieving this is using whipped egg whites, which are full of tiny air bubbles. 

Beat your egg whites into soft peaks, and fold them very gently into your batter. Be careful not to overmix, or you will release all the air. This method is not suitable for all types of baking, but can work for soufflés, pancakes, meringues and waffles.

Self-Rising Flour

If you have self-rising flour in your cupboard, you’re not actually out of baking powder at all. Self-rising flour is actually flour with added baking powder, so all you need to do is swap your regular flour for self-rising, leave out the baking powder and salt in the recipe, and you’re set.

Club Soda

Club soda can also be used to replace baking powder in some recipes. It actually contains baking soda and is slightly acidic, creating the reaction needed to make dough or batter rise. The effect is only quite small though, so it’s best used in recipes that only require a slight rise, like pancakes, for example. Use it to replace the liquids in your recipe, like water or milk.

We hope at least one of these alternatives can help to rescue your baking project if you ever find yourself out of baking powder. And to save yourself from getting caught out next time, here’s how to make baking powder at home.