Does Bicarbonate of soda (baking soda) expire?
Sodium bicarbonate is a stable salt and does not rot, but it reacts with any acidity and moisture it meets, including in the air of a kitchen, so an open tub gradually converts at the surface and lifts less. It only produces gas in a recipe when something acidic is present — buttermilk, yoghurt, vinegar, cocoa — which is the difference between it and baking powder that catches people out. Test it with a splash of vinegar: it should foam immediately and hard. For scrubbing, deodorising and fridge duty, age is irrelevant.
How to store it
- Airtight; the cardboard box it comes in is not airtight.
How to tell it has gone
- A teaspoon in vinegar should foam violently. A weak fizz means use it for cleaning instead.
"Use by" and "best before" are legally different. Use-by is a safety date and should be respected; best-before is about quality, and food is usually fine well past it. Where the two diverge matters, the page above says which applies.
Common questions
- Does Bicarbonate of soda (baking soda) expire?
- It lasts for years as a cleaner and a deodoriser, but its baking power fades once the tub has been opened a while.
- How long does Bicarbonate of soda (baking soda) last?
- About 2 years opened for baking; indefinite for cleaning
Related pages
- Does Eggs expire? Eggs stay usable for weeks past the date on the box, and the float test tells you about age rather than safety.
- Does Medicines expire? Most solid medicines keep much of their potency for years past the date — but a handful genuinely must not be used late.
- Does Petrol and diesel expire? Petrol goes stale within months, and ethanol blends go faster because they absorb water.
- Does Batteries expire? They self-discharge on the shelf, at very different rates by chemistry — and alkalines leak when flat.
- Does Wine expire? The great majority of wine is meant to be drunk within a year or two. Very little of it improves.
- Does Chocolate expire? It keeps far longer than the date. The white bloom on old chocolate is fat or sugar, not mould.
- Does Household bleach expire? It loses strength within months and eventually becomes salt water. This surprises most people.
- Does Paint expire? Unopened water-based paint keeps a few years; opened tins depend entirely on how well they were sealed.
- Does Honey expire? Does not expire
- Does Milk expire? Has a real expiry date
- Does Sunscreen expire? Unsafe or ineffective after the date
- Does Salt expire? Does not expire
- Does Frozen food expire? Indefinite if stored properly
- Does Canned food expire? Indefinite if stored properly
Sources
- US Food and Drug Administration — FDA (Public domain (US Government))