How long does Kefir (fermented milk) last after opening?

Updated 2026-08-07 · Free · No sign-up

Once opened, Kefir (fermented milk) keeps about 1–2 days in the fridge. Unopened, it keeps about 1 week.

Source: USDA FoodKeeper v128 · Category: Dairy & eggs

How long Kefir (fermented milk) keeps

SituationKeeps for
Unopened · fridge1 week
Opened · fridge1–2 days
FreezerNot recommended

Only situations with a published figure are listed. A blank isn't “forever” — it means no reliable number is published for it.

Storage

How to tell if Kefir (fermented milk) has gone bad

These are the general spoilage signs for dairy & eggs — never taste something to test it. When in doubt, throw it out.

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FAQ

How long does Kefir (fermented milk) last after opening?

About 1–2 days refrigerated at 40°F (4°C) or below, according to USDA FoodKeeper v128. Refrigerate it once it's open.

Does Kefir (fermented milk) need to be refrigerated after opening?

Yes — keep Kefir (fermented milk) at 40°F (4°C) or below once it's open. Refrigerate at 40°F (4°C) or below.

How can you tell if Kefir (fermented milk) is bad?

Look for: Sour or off smell; Mould or fuzzy spots; Curdled, slimy, lumpy, or separated texture; Yellowing or other discoloration. Never taste something to test it — when in doubt, throw it out.

Can you freeze Kefir (fermented milk)?

USDA FoodKeeper v128 does not recommend freezing Kefir (fermented milk) — it survives but the texture or quality suffers badly.

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