Cow’s milk is the most popular type of milk in the United States, with the average American drinking 18 gallons of milk per year! It’s estimated that around 94% of households in the US have cow’s milk in it. If that’s true for you, then you’ll need to know when milk goes bad!
Milk goes bad around 7-10 days past its best-by date when sealed and 2-3 days past its best-by date when opened. If it’s frozen, milk will last around six months. If you’ve opened a jug before it’s best-by date, it’s ideal to use the milk within 7-10 days, even if it’s before it’s best-by date.
For tips on how to get the longest shelf life out of milk, keep reading!
What are the different types of milk?
Cow’s milk is often referred to as “regular milk” to differentiate it between the numerous plant-based and other mammal-based milk. For this article, we’re referring to cow’s milk as “milk”.
Different types of cow’s milk fall under this umbrella and include:
- Skim (nonfat) milk: 0% fat content
- Low-fat/1% milkfat
- Reduced-fat/2% milkfat
- Whole milk/3.25% milkfat
- Lactose-free milk (varying fat content) – lactose-free milk does contain lactose, but it also has the lactase enzyme added to help break down the lactose (milk sugar)
- Flavored cow’s milk (varying fat content) – common flavors are chocolate and strawberry
Milk is pasteurized (heated to kill bacteria) and homogenized, which is the process used to evenly disperse the fat globules throughout the liquid. It also has vitamin D added to it to complement its natural calcium content (both calcium and vitamin D are important for bone health).
Some types of cow’s milk are ultra-high temperature (UHT), which is shelf-stable at room temperature for several months. This article is NOT referring to UHT milk, but perishable milk that is stored in the refrigerator at all times.
What is the shelf life of milk?
Regular cow’s milk (all types of fat concentrations) is perishable, which is why it has to be refrigerated at all times.
The shelf life of milk depends on when it is packaged. The good news is that milk comes with a printed ‘best by” date on the package which gives an indicator of how long the milk should last. (If you don’t plan on using milk quickly, look for the later best-by date when choosing a jug at the store.)
Milk is generally good for 5-7 days past its best-by date if it’s sealed. If you’ve opened it, it’ll only be good for about 2-3 days after the best-by date, so you’ll need to use it quickly.
How long does milk go bad after opening?
Once you twist the cap off the carton or jug of milk, you should use it within 7-10 days. If you wait longer than that, there’s a chance the milk might go sour, even if it’s before the best-by date.
Can you use milk after its expiration date?
As we mentioned earlier, you can likely use milk after its best-by date, but only if there aren’t any signs of spoilage (we’ll cover that next).
If it’s been sealed, you can usually use milk for 5-7 days past the best-by date. Once it’s opened, it’ll likely go bad after around 2-3 days after the best-by date.
How to tell if milk went bad
Color: Milk should be white, so if it takes on a yellow tinge, it’s time to toss it.
Consistency: Mik should be smooth and creamy without any lumps or solid parts to it. One of the telltale signs of milk that’s gone bad is the formation of curdles, which means the milk’s pH drops and causes the milk proteins to stick together. If you spot curdles, absolutely toss the milk.
Smell: Most of us know that “sour milk” smell, so be on the lookout for it when you’re trying to gauge if milk has gone bad.
Taste: Just like the sour milk smell is hard to miss, the taste of spoiled milk is pretty distinctive too. Instead of tasting sweet and pleasant, old milk will taste bitter. The bad taste will only get worse the longer the milk has been spoiled.
What’s the danger in using milk after it’s gone bad?
If you take a few sips of milk before noticing it’s gone bad, don’t fret – consuming a little isn’t likely to do any harm. If you drink enough spoiled milk, you might develop stomach symptoms similar to food poisoning which can include stomach pain, vomiting, and diarrhea (no fun), which is why it’s important to check for signs of spoilage if the milk is on the older side.
Best storage practices for milk
- Store milk in a tightly sealed container, such as the jug or carton it came in. If you choose to transfer milk to another container, make sure it’s covered to keep oxygen out, which can cause it to go bad more quickly.
- The optimal temperature for milk storage is 37 degrees Fahrenheit. If your fridge isn’t that cold, then store the milk towards the back of a bottom shelf, where it’ll be a bit cooler than other parts of the fridge.
- If you don’t plan on using milk for a while, you can freeze it. Just pour a little bit of milk out to allow room for expansion and then freeze it. (It’s ideal to freeze milk in glass bottles, which aren’t prone to cracking and leaking after you thaw it.)
Milk shelf life summary
| Refrigerator (sealed) | Refrigerator – opened | Frozen | |
| Milk (all types of cow’s milk, not counting UHT milk) | Until best-by date, or up to 5-7 days past it when sealed | 7-10 days (if not past its best-by date) | Up to 6 months, but using within one month of freezing is ideal |
FAQs:
Spoiled milk is usually thicker than fresh milk (sometimes with clumps/curdles) and can have a yellow tint. It’ll also smell and taste sour.
Milk will likely be okay to drink for around 5-7 days past its best-by date if it’s been sealed. If it’s been opened and the best-by date hits, plan to use it within 2-3 days unless there are already signs of spoilage.
Leave a Comment