Bicarbonate of Soda vs Baking Powder

When it comes to baking, sometimes the smallest ingredients can have the biggest impact. Two of the most commonly confused – yet absolutely essential – are bicarbonate of soda and baking powder. They may look similar, and they’re both used to make your bakes rise, but they work in very different ways. Understanding how and when to use each one can take your baking from good to great. 

Bicarbonate of soda (also known as bicarb or baking soda) is a type of rising agent that’s used to achieve light and fluffy bakes. Its active ingredient is called sodium bicarbonate and it’s a chemical compound that is natural alkali. 

Not sure exactly what bicarbonate of soda is good for? Because baking soda is alkaline, it needs to be mixed with something acidic to help activate it. It’s brilliant at adding extra lift to certain kinds of bakes, particularly recipes for things like sticky gingerbread, delicious soda bread and melt-in-the-mouth cookies. 

When bicarb reacts with an acid, it produces carbon dioxide gas, which forms bubbles in your batter or dough. These bubbles expand in the heat of the oven, helping your bake rise. 

• Buttermilk 
• Yoghurt 
• Vinegar 
• Lemon or lime juice 
• Brown sugar 
• Black treacle  
• Honey 
• Cocoa powder  

• Gingerbread 
• Carrot Cakes 
• Banana bread 
• Muffins and quick breads 

As well as baking bicarb is also very good as a cleaning agent  
• Try mixing bicarbonate of soda with vinegar to create a kitchen cleaning spray; 
• Make a paste with lemon juice to help remove grease from your oven; 
• Add a scoop to your washing machine to get rid of stains in clothing. 
• Alternatively, pop some in an open bowl in your fridge to eliminate any unsavoury odours. 

Baking soda has its place in the health and beauty world too. Its ability to absorb odours makes it a key ingredient in many natural deodorants, while many brands of whitening toothpaste also include it. Do you use mouthwash before or after you brush? Make your own by mixing half a teaspoon of bicarbonate of soda with 120ml of water. 

If you use too much bicarb or there isn’t enough acid to balance it, it can leave a metallic or soapy taste in your bake. Always use only the amount needed. 

When it comes to what’s in baking powder, the answer is simple: a combination of bicarbonate of soda (an alkali) and cream of tartar (an acid). Some versions also include cornflour. This helps to absorb any excess moisture that might get into the powder when it’s stored and ultimately affects how well it works. 

You’ll typically add baking powder to your dry ingredients and then activate it by mixing in wet ingredients such as milk, eggs, oil or butter. 

Just add liquid! Most baking powders are double-acting, which means: 
1- They begin to release gas as soon as they’re mixed with wet ingredients. 
2- They release a second burst of gas when exposed to oven heat. 
This gives your bakes a nice, consistent rise and more stability. 

• Sponge cakes 
• Cupcakes 
• Pancakes 
• Waffles 
• Plain biscuits or cookies (without acidic ingredients) 
 

Yes, but it depends on the recipe. Here's how: 
Bicarb instead of Baking Powder: 
You’ll need to add an acidic ingredient to activate it. 
Substitute: 1 tsp baking powder = ¼ tsp bicarbonate of soda + ½ tsp lemon juice or vinegar 


Baking Powder instead of Bicarb: 
This works if you don’t have an acid in the recipe. 
Substitute: ¼ tsp bicarbonate of soda = 1 tsp baking powder 

Note: Baking powder contains starch, so it may slightly change the texture or flavour if used in large amounts. 

Always measure accurately – too much or too little can ruin your bake. 
Mix dry and wet separately first – then combine gently to avoid losing air. 
Check freshness – bicarb and baking powder lose potency over time (usually 6–12 months). 
Don’t let the batter sit too long – once activated, you want to get it into the oven quickly, especially with single-acting agents. 

• Bicarb: Mix a pinch with vinegar – it should fizz immediately. 
• Baking Powder: Mix a spoonful with hot water – it should bubble up. 
 

So, is baking powder the same as bicarbonate of soda? The short answer is no. While baking powder contains bicarb as a key ingredient, they are not always interchangeable,
Baking powder tends to be the more popular of the two rising agents. That’s because it’s not quite as strong as bicarbonate of soda and can therefore be used in a wider range of recipes. It also doesn’t need anything added to it – besides a little liquid – to activate it. 

Baking soda still has its uses though. It’s often included in recipes which have an acidic ingredient, such as lemon juice, yoghurt or brown sugar, which might give it a bitter taste. Adding some bicarbonate of soda will help neutralise the mix and ensure it rises correctly. 

Can you add Bicarbonate of Soda to plain flour? 
Yes, bicarbonate of soda is most commonly added to recipes with plain flour. That’s because self-rising flour contains baking powder and the combination of the two rising agents can sometimes give your final bakes an acidic taste. Unless the recipe calls specifically for self-rising flour, it’s best to use plain. 

Is Bicarbonate of Soda gluten free? 
Unlike baking powder, which often contains wheat-based starch to keep it dry, bicarbonate of soda is naturally gluten-free. 

Is Baking Powder Gluten Free? 
It’s one of the most popular baking ingredients – but does baking powder have gluten in it? While baking powder is naturally gluten-free due to the fact both bicarbonate of soda and cream of tartar doesn’t hold wheat, that doesn’t necessarily mean all versions of it are. 
Many baking powders contain an extra ingredient: starch. Why? Because it can help prevent the powder from getting damp during storage and, consequently, becoming inactive. Starch isn’t always gluten-free, so it’s best to steer clear of baking powders with it added if you’re gluten intolerant. 

How much Baking Powder do I add to plain flour? 
To work out how much baking powder to add to your flour mix, it’s best to look at your recipe’s ingredients list. Make sure you always use a dry teaspoon to measure it out to avoid activating it too early. 
 

Understanding the difference between bicarb and baking powder can help you become a more confident baker. They may look similar, but they work differently—so choosing the right one can make all the difference in how your cakes rise and taste.