How long does kefir last?
Short answer: Kefir (fermented milk) keeps 1 week (1–2 days once opened) in the fridge and doesn't freeze well.
Storage chart
| Type | Fridge | Freezer |
|---|---|---|
| fermented milk | 1 week; 1–2 days (after opening) | Not recommended |
Fridge at 40°F (4°C) or colder, freezer at 0°F (−18°C). Freezer times are for best quality; food kept frozen stays safe indefinitely.
Keep it longer
Keep dairy on a shelf, not in the door, where the temperature swings every time the fridge opens.
Common questions
How long does kefir last in the fridge?
1 week (1–2 days once opened) in the refrigerator at 40°F (4°C) or below, according to USDA FoodKeeper data.
Can you freeze kefir?
Freezing isn't recommended for kefir; the texture and quality suffer.
How can I tell if kefir has gone bad?
Throw it out if you see mold, a slimy texture, an off smell or an odd color. For anything perishable, go by the storage time rather than smell: bacteria that cause food poisoning don't usually change how food looks or smells.
More dairy products & eggs
Source: USDA FoodKeeper data (USDA Food Safety and Inspection Service). Updated 2026-10-13. General information, not medical advice. When in doubt, throw it out.