Bicarb (Baking Soda) — Honest UK Guide to What It Does
Three real uses. Plenty of myths.
Bicarbonate of soda (bicarb/baking soda) is a cheap, multi-purpose household staple. Its three legitimate uses are: occasional, short-term relief of heartburn; as a leavening agent in baking; and as a mild, non-toxic abrasive cleaner. It is NOT a daily wellness drink, cancer cure, or weight-loss aid. While generally safe for healthy adults in occasional, small doses, it is high in sodium and can be dangerous for people with high blood pressure, kidney or heart issues, or those on certain medications. Always use it sparingly and consult your GP if unsure.
Let's clear up the confusion right away: bicarbonate of soda, sodium bicarbonate, and baking soda are all names for the same white powder. In the UK, we often call it 'bicarb'. You'll find it in the baking aisle, in cleaning cupboards, and increasingly, in online wellness advice. But what does it actually do, and where is the evidence? This no-nonsense guide gives you the honest lowdown on its few real benefits, its many over-hyped claims, and the crucial safety rules everyone should know.
What Bicarb Actually Is
Sodium bicarbonate (NaHCO₃) — the basics
Bicarbonate of soda is a naturally occurring alkaline compound with a pH of approximately 8.3. Its chemical superpower is that it reacts with acids, producing carbon dioxide gas and water. This single reaction is the key to virtually all of its uses — from making cakes rise to neutralising stomach acid.
- pH 8.3 — mildly alkaline (a base)
- Reacts with acids → carbon dioxide (CO₂) + water
- Same product whether labelled "baking soda", "bicarbonate of soda", or "sodium bicarbonate"
In UK supermarkets like Tesco or Sainsbury's, a 200g tub costs between £0.85 and £1.50. Whether the package says 'bicarbonate of soda' or 'baking soda', it's the same product. Just ensure it's labelled 'food grade' if you plan to eat it, as cleaning-grade versions may have impurities. Stored in an airtight container, it lasts for years, though its potency for baking fades after about six months once opened.
For Heartburn — What's Real and What's Not
This is perhaps the most common medicinal use. When you have heartburn, stomach acid splashes up into your oesophagus. A small amount of bicarb can neutralise that acid, providing fast, temporary relief. The classic dose is half a teaspoon dissolved in 120ml (about half a glass) of water, drunk slowly. It can work in as little as 5-10 minutes.
However, the NHS is clear: this should only be for occasional, short-term use. Regular use is not recommended. Why? Firstly, bicarb is extremely high in sodium. That half-teaspoon dose contains roughly 600mg of sodium — that's a quarter of the recommended daily limit (2.4g sodium, or 6g salt) in one go, according to the British Heart Foundation. This can raise blood pressure and counteract the effects of blood pressure medications.
Secondly, relying on it can mask symptoms of more serious conditions like gastro-oesophageal reflux disease (GORD). For frequent heartburn, the NHS advises speaking to a pharmacist about longer-term solutions like Gaviscon or Rennies, which are formulated for more sustained use with a better safety profile.
For Baking — The Kitchen Science
This is where bicarb truly earns its place. In baking, it's a leavening agent. When it reacts with an acid in your mixture — such as buttermilk, yoghurt, lemon juice, or cream of tartar — it releases carbon dioxide bubbles. These bubbles get trapped in the batter or dough, causing it to rise and become light and fluffy. It's essential for recipes like soda bread, certain cakes, and classic scones.
A common point of confusion is bicarb versus baking powder. They are not the same. Bicarb is pure sodium bicarbonate and needs an acid to activate. Baking powder is a pre-mixed blend of bicarb, a dry acid (like cream of tartar), and a stabiliser like cornflour. You cannot swap them one-for-one. If a recipe calls for bicarb, it will also list an acidic ingredient. As a rough UK conversion guide, 1 teaspoon of baking powder is equivalent to about ¼ teaspoon of bicarb mixed with ½ teaspoon of cream of tartar.
For Cleaning — What Works
As a mild abrasive and alkaline substance, bicarb is a gentle yet effective cleaner. It's non-toxic and safer to use on food-prep surfaces than harsh bleach. Its scouring power helps lift stains and grease without scratching most surfaces.
Sink & Drain Unblocker
Tip half a cup of bicarb down the drain, follow with a cup of white vinegar. Let it fizz for 15 minutes, then flush with a full kettle of boiling water. Great for slow-running drains.
Mug & Cup Stain Remover
Make a paste with bicarb and a little water. Apply to tea or coffee stains with a cloth, scrub gently, and rinse. Works a treat.
Oven Rack Cleaner
Place racks in the bathtub or a large sink. Sprinkle with half a cup of bicarb and cover with very hot water. Soak overnight, then scrub off the softened grime.
Carpet Deodoriser
Sprinkle bicarb lightly over carpets, leave for 30 minutes to absorb odours, then vacuum thoroughly. Always patch-test first.
The Wellness Claims Bicarb Does NOT Support
This is where we need to be most vigilant. Bicarb is not a wellness tonic. Here's an honest comparison of what it actually does versus what it emphatically does not.
✅ Real uses, evidence-backed
- Occasional heartburn relief
- Baking leavening agent
- Mild kitchen abrasive
- Drain cleaning with vinegar
- Athletic performance buffering (elite only)
⚠️ Bunk claims to skip
- Alkaline-diet weight loss
- "Blood alkalisation" cancer cure
- Daily detox tonic
- Miracle teeth whitening
- Cure for any chronic disease
Bicarb vs Baking Powder — The Confusion Fixed
To reiterate: Bicarbonate of soda (bicarb) = pure sodium bicarbonate. It is a single ingredient. Baking powder = a mixture of bicarb + a built-in acid (cream of tartar) + a buffer (cornflour). In UK recipes, they are not interchangeable. If you only have bicarb and a recipe calls for baking powder, you must add an acid like cream of tartar to activate it. Using bicarb alone in a recipe without sufficient acid will result in a bitter, soapy taste and poor rise.
| Property | Bicarbonate of soda ✓ | Baking powder |
|---|---|---|
| Active ingredient | NaHCO₃ only | NaHCO₃ + acid + cornflour |
| Needs acid to activate | Yes | No — pre-mixed |
| Calories per tsp | 0 | 0 |
| Substitution ratio | 1 tsp BP = ¼ tsp bicarb + ½ tsp cream of tartar | — |
| Common UK brand | Dr Oetker | McDougalls |
Safety: Who Should NOT Use Bicarb (Orally)
This is critical. You should avoid taking bicarbonate of soda internally if any of the following apply to you. These rules are not optional — they are based on real medical risk.
⚠️ Five Safety Rules — Know These Before Using Bicarb Orally
- Skip if hypertensive or on a low-sodium diet — ½ tsp = ~600mg sodium, a quarter of your daily limit in one go
- Never give to children under 12 — electrolyte imbalance risk is high in young children
- Avoid in pregnancy without GP approval — high sodium can cause fluid retention and raise blood pressure
- Don't take after a large meal — the CO₂ gas produced can, in rare cases, cause gastric rupture
- Stop using and see your GP if heartburn lasts >3 weeks — persistent symptoms may indicate GORD or something more serious
What Readers Are Telling Us
"Bicarb + vinegar saved me from calling a plumber. Drain cleared in 30 min for 50p."
★★★★★
"Used to drink it daily for 'alkalising' until my GP flagged my BP. Stopped, BP dropped."
★★★★☆
"Half a teaspoon for occasional heartburn after a curry — works fast. Not daily though."
★★★★★
"Bicarb on baked oven racks overnight. Came up cleaner than oven sprays."
★★★★★
Frequently Asked Questions
Three real uses. Plenty of marketing nonsense. See your GP for chronic heartburn.
Bicarbonate of soda is a genuinely useful, low-cost product with three solid, evidence-backed roles: a quick-fix for rare heartburn, a baking essential, and a safe household cleaner. Its value lies in its simplicity and affordability. However, it is surrounded by dangerous wellness myths. Respect its power, understand its limitations, and always prioritise safety — especially regarding its high sodium content and interactions with health conditions. Use it wisely, and don't believe the hype. If in doubt about any health use, a quick chat with your pharmacist is always the best step.
Related reading: Low-Calorie Drinks UK Guide · Best Fruits for Weight Loss UK · Lowest Calorie Alcohol UK Guide
Published 26 April 2026 · Last reviewed 26 April 2026 · Walton Surgery NHS GP Practice, UK · All health advice in this article is aligned with current NHS guidance. This article is for informational purposes only and does not replace professional medical advice.