How long does cooking oil last?

Unopened vegetable cooking oil keeps its quality for about 1–2 years in a cool, dark place, but only about 4–6 months once opened before it starts to go rancid.

	Cooking Oil
Unopened	About 1–2 years (check the best-by date)
Opened	About 4–6 months
Ideal storage	Cool, dark place; light and heat speed up rancidity.

Storage tips

Rancid oil smells like crayons or old paint. It is not acutely dangerous but tastes bad and has lost nutrients.
Oil is the most calorie-dense item you can store; rotate small bottles rather than holding one huge jug.

Signs it has gone bad

A rancid smell, often described as crayons, putty or old paint (oils, nuts, nut butters, whole-milk powder)
Mold on the surface or under the lid
Off colors or a sour smell
Hard clumps in sugar or salt are only moisture and are harmless; break them up

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