How long can unopened milk sit out?

In this article, we will answer the question “How long can unopened milk sit out?”, what is the shelf-life of milk, how to store milk, can you drink expired milk, and how to tell if the milk has gone bad.

How long can unopened milk sit out?

According to the USDA, unopened milk should not sit out for more than 2 hours. If the outside temperatures are warmer, that is 90F or above, discard the milk after an hour.

What is the shelf-life of milk?

Regular milk 

Once opened, milk can last 4-7 days if refrigerated at all times. Make sure the milk maintains a temperature of 40 degrees Fahrenheit or below. 

Organic milk 

Unlike processed milk, organic milk can last for up to a month in the fridge. This is because organic milk does not contain antibiotic residues and traces of growth hormones, unlike regular milk. 

Raw milk 

Stored at a consistent temperature of 36-38°F, raw milk does not keep for more than 7-10 days. If kept at warm temperatures for prolonged periods, raw milk starts to grow lactobacilli bacteria that ferment the milk sugar (lactose) and produce lactic acid.

UHT milk 

UHT milk is also known as shelf-stable milk and rightfully so. It can last up to a month t room temperature without spoiling or undergoing undesirable changes. This only applies if the milk is unopened. 

Once opened, even the UHT milk should be discarded after 7 days. The long shelf-life of the UHT milk is attributed to its processing method and aseptic packaging. UHT milk is heated at 275°F for 2-4 seconds.

Breast milk 

Breast milk should be refrigerated at all times. Discard the breast milk if it has been sitting out at 77°F for four hours or more. Do not keep the breast milk refrigerated for more than 4 days. If you want to last longer, say for up to 6 months, consider freezing it within 3 days of refrigeration. 

Can you drink expired milk?

If the milk is unopened, it will still be good for about a week past its expiry or printed date. If opened, there is a risk that it may be spoiled. The risk is significantly low if the milk has just crossed its expiry and was properly stored in the fridge. 

Now the question arises of whether you should throw it out or not. To decide, it is recommended that you closely inspect the milk for spoilage. If the milk exhibits even a single sign of spoilage, get rid of it. If you are unsure, discard the milk. Because it is better to be safe than sorry!

How to store milk to prevent spoilage?

Make sure the milk stays at refrigeration temperature or lower at all times. Tick off the milk at the end of your grocery shopping. So that you can minimize the time that milk spends outside of refrigeration. Put it back in the fridge as soon as you get home.

However tempting it may be to put your milk cartons or bottles in the fridge door, do not do it, not unless you want to reduce the shelf-life of the milk by half. 

The fridge door is where most of the temperature fluctuations happen. Frequent exposure to temperature fluctuations expedites the spoilage of milk.

Ideally, you should keep your milk container in the coldest spot inside the fridge which lies where the ice tray is located, usually at the bottom or at the back of the fridge.

It is important that the milk container, original or not, has a sound seal. A tight seal keeps the air, bacteria, unwanted odors, and other contaminants at bay. If the seal of the original milk container is broken, transfer the milk to an air-tight container.

UHT and canned milk can sit out as long as they are opened. Even then you should make sure that the outside temperature does not go abnormally high. Once opened, they belong in the fridge.

If you are a parent and want to pack milk in lunch for your kid. Do it by sandwiching the milk bottle in ice packs. Better yet, pack them a shelf-safe or UHT milk bottle. Instruct them to finish the bottle after opening it. Once the UHT milk is opened, it is treated like any other type of milk.

How to tell if the milk has gone bad?

Smell: Spoiled milk smells sour due to the lactic acid produced by the spoilage bacteria.

Appearance: If you suspect the milk is spoiled, you are looking for a ropy or lumpy texture and a yellow color. 

Mold: Mold grows on milk in the form of white or green patches or spots. Get rid of moldy milk if you spot it.


In this article, we answered the question “How long can unopened milk sit out?”, what is the shelf-life of milk, how to store milk, can you drink expired milk, and how to tell if the milk has gone bad.


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