Milk
Milk usually keeps 5 to 7 days past the Sell-By date when kept cold, and about a week once opened. Smell and look decide — the date is a guide.
Why milk keeps as long as it does
How long milk lasts depends on how it was treated and how cold it is kept. Most US milk is pasteurised and carries a Sell-By date — a store-rotation date, not a hard deadline. Kept continuously cold, it is usually good for about five to seven days past that date, and roughly a week once opened. Ultra-pasteurised (UHT) milk lasts longer unopened, but once opened it behaves like regular milk and should be used within days.
The key is an unbroken cold chain at or below 40 °F (4 °C) and clean handling — never drink straight from the carton, as saliva introduces bacteria. The fridge door is the worst spot because the temperature swings each time it opens; milk keeps better on an inner shelf. Unlike a plain Best-By date, milk always rewards a quick smell test.
The type matters too: raw farm milk is untreated and keeps only a few days, while extended-shelf-life (ESL) milk sits between fresh and UHT and stays good for about three weeks unopened. Low-fat milk does not spoil faster than whole milk — cold storage is what counts. A simple everyday test: if the milk smells neutral when you open it and pours cleanly from the carton, it is fine; if you see flakes at the rim or while pouring, it is done. And if you freeze milk, note that the fat and water can separate, so thawed milk suits cooking and baking better than drinking straight.
How do I spot bad milk?
Spoiled milk gives itself away quickly and clearly:
A sour, sharp smell is the clearest sign. Fresh milk smells neutral.
Curdled or lumpy milk has spoiled — discard it.
If a small sip tastes sour or bitter, the milk is done. When in doubt, pour it out.
Add a splash of milk to a glass or a hot coffee. If it stays smooth and liquid, it is fine. If it forms flakes or lumps at once, it has soured — then do not drink it.
Shelf life at a glance
Milk type and state decide between days and months:
| State | Shelf life |
|---|---|
| Pasteurised, unopened refrigerated | 5–7 days past Sell-By |
| Pasteurised, opened | about 1 week |
| UHT, unopened | several months |
| UHT, opened refrigerated | 7–10 days |
Store it right
The right storage keeps milk fresh longest:
Keep it cold — at or below 40 °F (4 °C), on an inner shelf rather than the door.
Do not drink from the carton — saliva adds bacteria and shortens its life.
Reseal well — close it and return it to the fridge promptly after each use.
Refrigerate promptly — do not leave milk sitting out on the counter.
Common myths
A few milk myths persist:
Not necessarily — unopened milk kept cold is often good several days past the Sell-By date. Smell decides.
Better not to drink it — but slightly soured milk can still work for baking, like pancakes, as long as there is no mould.
Only unopened and to its date. Once opened, UHT milk keeps only a week or so in the fridge.
Soured (not UHT) milk is not automatically trash: it works for baking, pancakes or making a quick soft cheese. UHT milk, however, turns bitter rather than sour when it goes off — better not to use that.