Yogurt
Unopened and kept cold, yogurt is often good 1 to 2 weeks past the Sell-By date. That date is not an expiry — look, smell and taste decide.
Why yogurt keeps so well
Yogurt is made by lactic-acid bacteria that sour the milk. That acidic environment, with a pH around 4, holds back most harmful microbes — so yogurt partly preserves itself. That is why an unopened, continuously refrigerated cup of plain yogurt is almost always still good one to two weeks past the Sell-By date. That date is a guarantee of full quality from the maker, not a throw-away deadline.
Opened cups and yogurts with fruit or cream are a different story. Once the cup is open, microbes get in from the air and the spoon, and fruit additions spoil faster. Here the quick sensory check is especially worth it. The rule: look, smell, taste — and less good yogurt ends up in the trash.
Roughly a third of the world's food is thrown away, and dairy is among the most common victims of a misread date. Yet yogurt reliably shows for itself whether it is still good. A look and a sniff are enough.
Source: FAO / USDAHow do I spot bad yogurt?
Use all your senses — do not go by the date alone:
Fuzzy, coloured spots on the surface are a clear stop sign. Discard the whole cup, do not just scoop it off.
A sharp, yeasty or fermented smell, or a bulging lid and bubbles, means unwanted microbes have multiplied.
A clear liquid on top is completely normal — just stir it back in. It is no sign of spoilage.
Shelf life at a glance
How long yogurt keeps depends on type and state. This table shows the typical cases:
| State | Shelf life |
|---|---|
| Plain, unopened refrigerated | 1–2 weeks past date |
| Fruit/cream, unopened | a few days past date |
| Opened, refrigerated | 3–5 days |
| Mold or fermented smell | discard |
Store it right
The right storage keeps yogurt fresh longer:
Keep it cold — at or below 40 °F (4 °C), toward the back of the fridge, not in the door.
Clean spoon — never dip a licked spoon back in; it introduces microbes.
Seal it well — cover opened cups with the lid or foil.
Keep the cold chain — refrigerate promptly after shopping and do not leave it out warm.
Common myths
A few yogurt myths persist:
Wrong — unopened plain yogurt is often good one to two weeks longer when cold. Check, do not toss.
No — that is whey, which naturally separates. Just stir it in.
Not with yogurt — the mold threads run through the soft mass. Discard the whole cup.
Use yogurt up before it turns: in smoothies, for baking, or as a marinade. And a spoonful of live yogurt works as a starter culture to make a fresh batch of your own.