How long does Buttermilk last in the fridge?
Turning the range into a date
Buttermilk keeps 1–2 weeks sealed in the fridge. The window here is 2 weeks, short enough that the day it went in is worth writing down.
- In the freezerUse by3 months after the day you bought it
- Unopened · in the fridgeUse by1 week to 2 weeks after the day you bought it
The methods the USDA actually rates for this item
The USDA rates only 2 of its nine storage methods for this item, and the freezer from the day of purchase and refrigerator from the day of purchase are what it rates. The other 7 slots are blank, and a blank is not a zero: it means no published figure, not that the method fails. Freezing extends it by 6.4 times over the sealed fridge, from 2 weeks to 3 months.
Every storage figure the USDA publishes for this item
The USDA rates this item cold or frozen and never at room temperature: no pantry figure exists for it, as for 222 of the 466 foods in the data that get no pantry time at all.
- In the freezer3 months
- Unopened · in the fridge1 week to 2 weeks
Can you freeze buttermilk?
Yes. The USDA gives buttermilk 3 months in the freezer from the day you buy it, and held at 0 °F food stays safe beyond that: the figure is about quality. Dairy can separate or turn grainy once thawed, so frozen it is better cooked with than eaten as it was.
How to tell if buttermilk has gone bad
Go by the date first: buttermilk keeps 1–2 weeks sealed in the fridge. Sour or off smell, lumps in milk or cream, and mold mean it goes out. On hard cheese, cut away 1 inch around a moldy spot; soft cheese with mold goes out whole.
Sources: USDA FSIS: the danger zone USDA FSIS: freezing and food safety USDA FSIS: molds on food FDA: are you storing food safely FoodSafety.gov: the FoodKeeper app.
Is it still safe to eat, or just past its best?
The answer at the top of this page reads 1 week to 2 weeks in the fridge. What decides that is the food: the source files Buttermilk under Dairy Products & Eggs, a heading it keeps for perishable food. Past it, it is not safe to eat: throw it out without tasting, because bacteria build up while food still looks and smells fine.
The figure in the freezer here is a quality window. The same page carries windows of more than one kind, so which sentence applies depends on which row you are reading, not on the food.
It is past the date. Now what?
Say the calculator above puts Buttermilk past its 1 week to 2 weeks in the fridge window, or the container sat out on the counter overnight. Throw the container out without tasting it, and count any hours it already spent out of the refrigerator as part of that window rather than on top of it.
The USDA's limit for perishable food standing at room temperature is 2 hours, or 1 hour when the kitchen is above 90 °F, and that clock runs whatever the storage figure says. Freezing stops the clock but does not turn it back: food already past its window is not rescued by putting it in the freezer. The whole rule, including the cases the source does not cover, is set out under what to do when the date has passed.
Items that behave the same way
All 6 of the 6 items nearest this item keep exactly as long as it does, 2 weeks, so the ranking around it is a tie rather than an order.
Where these numbers come from
Every storage time on this page is the USDA’s own published figure from the FoodKeeper data, one of the 9 it keeps per food, reproduced unchanged and never an estimate of ours. Where the USDA lists several kinds under one name, each kind keeps its own windows, and the page names the kind its answer is for. The dates and multipliers are ours, computed from those ranges.
Source: USDA FoodKeeper, retrieved 1 September 2026. Found a figure that does not match the source? Tell us on the contact page. How the site is built is on the method page.
KeepsUntil is an independent reference built on public USDA data. It is not affiliated with, endorsed by, or connected to the U.S. Department of Agriculture or the Food and Drug Administration. Whether a given window is a safety limit or a quality window is stated on the page that prints it.