Does Butter expire?
Does Butter expire?
It goes rancid rather than dangerous. A month or two in the fridge past the date, and up to a year frozen.
Fridge: 1-3 months. Freezer: 6-12 months
Butter is around 80% fat and 16% water, and that low water content plus salt in salted butter makes it fairly resistant to bacterial growth. The failure is oxidation of the fat, which produces the sharp, cheesy, sour smell of rancid butter, and it happens fastest at the exposed surface and in light. Salted butter keeps noticeably longer than unsalted for the same reason. Butter also picks up fridge odours through its fat, so it should be wrapped rather than left open in a dish.
How to store it
- Wrapped or in a lidded dish in the fridge; freeze anything you will not use within a month.
- Keep only a few days worth in a butter dish at room temperature, and less in hot weather.
How to tell it has gone
- Sharp, sour or cheesy smell and a darker yellow rim on cut surfaces mean rancidity.
"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 Butter expire?
- It goes rancid rather than dangerous. A month or two in the fridge past the date, and up to a year frozen.
- How long does Butter last?
- Fridge: 1-3 months. Freezer: 6-12 months
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
- Food Safety and Inspection Service — US Department of Agriculture (Public domain (US Government))