Sodium Bicarbonate in Food and Baking
Sodium bicarbonate (CAS 144-55-8, NaHCO3), known in the kitchen as baking soda, is the classic chemical leavening agent. Its role in food is simple to describe and useful to understand: it releases carbon dioxide when it meets an acid or heat, and that gas raises dough and batter. As a food additive it is E500(ii), used as a leavening agent and acidity regulator.
How it works in baking
Sodium bicarbonate is a base. When it reacts with an acid it releases carbon dioxide:
NaHCO3 + acid -> salt + H2O + CO2
On its own (heated without acid) it also decomposes above about 50 °C, giving off CO2 and converting to sodium carbonate – which is why unreacted baking soda can leave a soapy, bitter taste if there is not enough acid to neutralise it. Good recipes balance bicarbonate against the acid.
| Leavening acid | Reacts | Typical use |
|---|---|---|
| Baking powder (balanced) | Partly in the bowl, partly in the oven | General baking |
| Buttermilk / soured milk | In the mix | Pancakes, soda bread, cakes |
| Citric / tartaric acid | In solution | Effervescent and instant reactions |
| Cream of tartar | In the mix, on heating | Cookies, some cakes |
| No acid (heat only) | On heating, above ~50 °C | Limited; can leave aftertaste |
Why the balance matters
Too little acid leaves residual sodium carbonate and an unpleasant taste; too much acid gives a sour, astringent crumb. The aim is to match the acid to the bicarbonate so that the CO2 needed for lift is produced and the leftover salts are neutral in flavour. This is why baking powder (which blends bicarbonate with a balanced acid and a starch carrier) is convenient, while recipes that use baking soda rely on an acid ingredient (buttermilk, yoghurt, molasses, cocoa, lemon).
Main food applications
| Application | Function |
|---|---|
| Bakery | Leavening in cakes, cookies, biscuits, muffins, soda bread |
| Beverages | Acidity regulator; effervescent and carbonated drinks |
| Effervescent products | CO2 release on dissolution (with an acid) |
| Processed food | pH and acidity control (E500) |
| Confectionery | Texture and pH control in some products |
Food-grade specification
Food use requires food-grade material with tight toxic-metal limits. PolyBlueChem supplies sodium bicarbonate to the following specification:
| Parameter | Specification |
|---|---|
| Content (as NaHCO3) | 99% min |
| Chloride (Cl) | 0.4% max |
| Arsenic | 0.0001% max |
| Heavy metals (as Pb) | 0.0005% max |
| Loss on drying | 0.20% max |
| pH value | 8.5 max |
| Ammonium salt (NH4) | Pass |
| Clarity | Pass |
| Whiteness | 85 min |
The arsenic (0.0001% max) and heavy-metals (0.0005% max) limits, together with whiteness and clarity, are what make the material suitable for food. A per-batch COA is available.
Storage and handling
- Keep sealed and dry; the powder should stay free-flowing.
- Store cool – it decomposes slowly above about 50 °C, so a warm store weakens it over time.
- Keep away from acids and strong odours; it can absorb smells.
Sodium and labelling
Because sodium bicarbonate supplies sodium as well as buffering, its use is counted toward the sodium content of the finished food. Formulators balance the bicarbonate against the acid and consider the total sodium contribution, especially in products with a sodium claim. As an additive it is labelled as E500(ii) in the EU and by its permitted name in other markets; check the labelling rule for your destination.
Frequently Asked Questions
Is baking soda the same as baking powder?
No. Baking soda is sodium bicarbonate (a base). Baking powder is bicarbonate blended with a balancing acid and a starch carrier, so it leavens by itself.
What is the E number?
E500(ii) is sodium bicarbonate (part of the E500 sodium carbonates group).
Why does my baking sometimes taste soapy?
Usually too little acid to neutralise the bicarbonate, so some converts to sodium carbonate on heating. Balance the bicarbonate against the acid.
Is sodium bicarbonate the same as caustic soda?
No. Caustic soda is sodium hydroxide (a very strong base); sodium bicarbonate is a mild base used safely in food.
Do you supply food grade?
Yes – to the specification above, with per-batch COA and SDS.
Related reading
- Xanthan gum (CAS 11138-66-2): properties, production and applications
- Sodium bicarbonate (CAS 144-55-8): properties, production and applications
- Sodium bicarbonate in animal feed
- Sodium bicarbonate vs sodium carbonate
- How to buy sodium bicarbonate
- Sodium bicarbonate (CAS 144-55-8) – product page
PolyBlueChem supplies food-grade sodium bicarbonate (CAS 144-55-8) for bakery, beverage and effervescent use, with per-batch COA and SDS. Contact us with your application and tonnage.