Does Buttermilk Go Bad? | Cook's Illustrated (2024)

FAQs

Does buttermilk ever go bad? ›

Guidelines from agricultural programs at various universities recommend consuming buttermilk within three weeks of the date stamped on the package. In the test kitchen, we've found that buttermilk won't turn truly bad (signified by mold growth) until at least three weeks after opening.

After 12 to 24 hours, the mixture will thicken. The longer you leave it out, the thicker and tangier the buttermilk will be. Depending on how warm your kitchen is, it may also take longer. Once the buttermilk has reached the texture and flavor you desire, store it in the refrigerator for up to a month.

The tartness of cultured buttermilk is primarily due to lactic acid produced by lactic acid bacteria while fermenting lactose, the primary sugar in milk.

Refrigerated butter should last up to a month past the printed date if it's unopened. If the butter has been opened, it can last up to two weeks past that printed date. If you're storing the butter longer term, unopened butter stored in the freezer can last anywhere from nine months to a year past the date.

Yet, if it's just a little off and slightly acidic, there are several ways to use it. Try using slightly spoiled milk in one of the following culinary applications: Baked goods. Substitute spoiled milk for regular milk, buttermilk, yogurt, or sour cream in recipes like biscuits, pancakes, scones, and cornbread.

You can freeze buttermilk, and you absolutely should if you don't think you'll use it up before it expires. It should stay good in the freezer for about three months — about two and a half months longer than refrigerated buttermilk.

Despite the way it sounds, buttermilk is neither sweet nor creamy — it actually tends to be quite bitter. It has a slightly thick consistency, similar to eggnog, and we do not recommend adding it to coffee of any sort. Buttermilk is much better for baking rather than drinking.

Buttermilk lasts for 1-2 weeks beyond the date printed on the carton, and it can usually even be used beyond that point for cooking and baking needs. Buttermilk is a dairy product now produced by adding a culture of lactic acid producing bacteria into whole milk.

Now, the buttermilk you buy at the supermarket is regular milk that has active cultures/good bacteria added to it. This creates a chemical reaction that causes the milk to thicken and develop a signature tangy flavor.

How long is homemade buttermilk good in the refrigerator? ›

Pour milk to a measuring glass or jug. Stir in lemon juice or vinegar. Let the milk mixture sit for about 10 minutes or until it thickens very slightly and milk curdles and milk is acidic. Use as needed or store in the fridge for up to 3 days.

The answer is absolutely, yes. In short: It's tart, refreshing, and seemingly pretty good for you. Despite the delicious-sounding name, buttermilk isn't butter, nor is it exactly milk. Traditionally, this liquid was the byproduct of churning cream into butter.

The soda has another important role in recipes with buttermilk. It neutralizes the sour taste of the milk. Thus I proportion my soda to neutralize the buttermilk (1/4 tsp. soda per cup of milk.)

You may know that fermented foods can last a long time, and lactic acid does inhibit the growth of bacteria, but unlike pickles or miso, buttermilk doesn't last for months. An opened container will only stay fresh for two weeks when stored in a refrigerator, and for up to three months if kept in the freezer.

The lemon juice or vinegar makes the milk more acidic, like buttermilk, and also causes the milk to curdle slightly and thicken, like buttermilk (the fact that it has curdled will not negatively impact your baked goods in any way).

You can freeze buttermilk, and you absolutely should if you don't think you'll use it up before it expires. It should stay good in the freezer for about three months — about two and a half months longer than refrigerated buttermilk.

Types of Soured Milk

Soured milk made by fermentation – as in cultured dairy products such as buttermilk and kefir – is produced by adding lactic acid bacteria such as lactobacillus to pasteurized milk and incubated at 104 to 111 degrees F for several hours.