Dairy Products & Eggs

How long does kefir last in the fridge?

1 week
Fridge, from purchase — USDA FoodKeeper guidance for kefir (fermented milk)

Sealed kefir keeps 1 week in the fridge, but USDA gives an opened bottle just 1–2 days — once the cap is off, drink it down rather than saving it.

How long does it keep?

Fridge, from purchase 1 week
Fridge, opened 1–2 days
Freezer Not recommended

Can you freeze kefir? FREEZES, BUT…

Can it sit out?

Kefir is perishable — the FSIS 2-hour rule applies.

Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).

The 2-hour rule, in full →

How to tell if kefir has gone bad

  • A boozy or yeasty smell beyond the usual sourness
  • A hard split, with a thick plug settled at the bottom
  • A bottle that has swelled or fizzes when opened
  • A mold ring at the neck or under the cap

When in doubt, throw it out.

Shake before pouring — kefir separates on its own in the cold, and that layer on top isn’t the trouble sign.

Quick answers

How long does kefir last in the fridge?

Sealed kefir keeps 1 week in the fridge, but USDA gives an opened bottle just 1–2 days — once the cap is off, drink it down rather than saving it.

Can you freeze kefir?

Kefir freezes safely and thaws thin and separated — blended into a smoothie it’s fine, poured into a glass it’s obvious.

How long can kefir sit out?

The FSIS 2-hour rule applies to kefir. Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).