Bicarbonate of soda is the white powder used to make cakes rise, to deodorise fridges, to scrub sinks and to soften water. It is the same substance as baking soda — one name is British and South African, the other American — and it is not the same as baking powder.
What is Bicarbonate Of Soda?
Bicarbonate of soda is sodium bicarbonate, a mild alkaline salt. It is sold as a fine white powder in supermarkets and pharmacies, as a food ingredient and general household product.
The naming causes constant confusion, so it is worth settling:
| Name | What it is |
|---|---|
| Bicarbonate of soda | Sodium bicarbonate — the British and South African name |
| Baking soda | The same thing, American name |
| Bicarb | The same thing, shortened |
| Baking powder | Different. Bicarbonate of soda plus a powdered acid, and usually a starch |
| Washing soda | Different. Sodium carbonate — much more alkaline, not edible |
| Caustic soda | Different. Sodium hydroxide — corrosive, never for food or skin |
Bicarbonate of soda and baking soda are interchangeable in any recipe or use.
Everything it does comes from one property: it is a mild alkali that releases carbon dioxide when it meets an acid. In baking, that gas lifts a cake. In cleaning, the alkalinity cuts grease and neutralises acidic smells, and the fine crystals scrub without scratching most surfaces.
What is Bicarbonate Of Soda commonly used for?
In baking:
- Raising cakes, muffins, scones and soda bread, where the recipe also contains an acid — buttermilk, yoghurt, sour milk, lemon juice, vinegar, honey, treacle or cocoa.
- Browning and crisping, since the alkalinity speeds up browning reactions.
The crucial baking point: bicarbonate of soda needs an acid to work. Baking powder already contains its own acid, which is why the two are not interchangeable. Using bicarbonate where a recipe calls for baking powder gives a flat result and a soapy, metallic taste. Using too much does the same.
Around the house:
- Deodorising fridges, freezers, bins, shoes and carpets, and scrubbing sinks, baths, tiles, ovens and pots.
- Removing burnt-on residue from pans, and tea and coffee stains from cups.
- Softening water in the wash, and boosting detergent.
- Cleaning drains, followed by citric acid or vinegar.
- Freshening mattresses and upholstery, sprinkled on and vacuumed off.
Common household applications
- Fridge deodoriser — an open tub at the back, replaced every couple of months.
- Sink, bath and oven — a paste of bicarb and water, left to sit, then scrubbed off.
- Burnt pans — a spoonful with water, simmered, then left to soak.
- Carpet, upholstery and mattresses — sprinkle, leave up to an hour, vacuum thoroughly.
- Laundry booster — a few tablespoons in the drum with detergent.
- Shoe deodoriser — a spoonful in each shoe overnight.
- Drain freshener — poured down, followed by vinegar, then hot water.
How to use Bicarbonate Of Soda appropriately
- For baking, measure it accurately and make sure the recipe contains an acid. More is not better — excess leaves a distinctly soapy taste.
- Do not substitute it for baking powder at the same quantity. Bicarbonate is roughly three times stronger, and needs its own acid.
- For cleaning, make a paste with a little water, let it sit, then scrub. Test on an inconspicuous area first, and rinse thoroughly — dried residue leaves a white film.
- Store it sealed and dry — it absorbs moisture and odours, which is why an open tub deodorises a fridge and an open packet goes flat.
- Check it is still active before baking: a spoonful in vinegar should fizz vigorously.
- Buy food-grade for cooking. Industrial or pool-grade sodium bicarbonate is not for food.
Safety, surfaces and situations to avoid
Bicarbonate of soda is about as benign as household products get, but there are real limits.
Surfaces to avoid:
- Aluminium — it discolours and pits it.
- Marble, granite and other natural stone, where the abrasion dulls the polish.
- Glass cooktops, non-stick pans and soft plastics, which scratch.
- Antique or lacquered wood, gold-leaf or painted ceramics, and anything with a delicate finish.
Never mix it with bleach or ammonia-based cleaners, or with vinegar in a sealed container — that reaction builds gas pressure. In an open drain it is fine.
Do not confuse it with caustic soda or washing soda — both are far more alkaline and can burn skin and eyes.
Taking it internally — it is a traditional heartburn remedy and does neutralise stomach acid, but it carries a substantial sodium load and repeated use can cause a rebound increase in acid. Do not take it regularly, do not give it to children, and do not take it at all with heart, kidney or blood pressure problems without asking a pharmacist. A proper antacid is a better choice.
Get medical help if a large quantity is swallowed, particularly by a child. Keep it out of the eyes, and rinse with plenty of water if it gets in.
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Frequently asked questions
What is bicarbonate of soda used for in baking? Making cakes, muffins, scones and soda bread rise. It only works if the recipe also contains an acid such as buttermilk, yoghurt, lemon juice, vinegar, honey or cocoa.
Is it the same as baking soda? Yes. Bicarbonate of soda is the British and South African name; baking soda is the American one.
Is it the same as baking powder? No. Baking powder is bicarbonate of soda plus a built-in acid. They are not interchangeable in the same quantity.
Can I use it instead of baking powder? Only if you also add an acid, and at about a third of the quantity. Otherwise the result is flat and tastes soapy.
Why does my cake taste soapy? Too much bicarbonate, or not enough acid to react with it.
Can I take it for heartburn? It does neutralise acid, but it carries a high sodium load and can cause rebound acid. Avoid it if you have blood pressure, heart or kidney problems, and ask a pharmacist about a proper antacid instead.
Can I mix it with vinegar to clean? In an open drain, yes. Never in a sealed container — the gas produced builds pressure.