Have you ever left milk sitting on the counter by mistake, and then wondered if it is safe to put it back into the fridge or consume it? We all know dairy products should be kept cool, but how soon does milk need to be refrigerated to stay safe?
How long can milk sit out? Milk should not be left at room temperature for more than two hours, or even just an hour in a warm room. If it gets left out, bacteria will quickly start breeding in the liquid, so the USDA recommends it be kept refrigerated at all times, and not left out for longer than necessary.
How Long Can You Leave Milk Out?
You can leave milk on the counter for up to two hours in a reasonably cool room, or an hour in a room with temperatures above 90 degrees F. Longer than this could mean that the milk will become unsafe to drink because bacteria will have spread throughout it.
Many people do leave milk out for more than two hours and then drink it without suffering from any ill effects. However, it is still advisable not to do this, especially if you are vulnerable. If nothing else, milk that has been left out will turn sour faster, even if it does not make you sick. This contributes to food waste and can be very frustrating.
What are the Dangers of Drinking Bad Milk?
Milk that has gone off may be harboring bacteria that is unsafe for you to consume, and these could cause food poisoning. There are many different kinds of bacteria that can grow in off milk, but some of the common ones include Bacillus cereus and Pseudomonas.
Any of the bacteria that grow in milk can make you sick, and the seriousness may vary. Some will cause nausea, vomiting, diarrhea, stomach cramps, headaches, fever, etc. In rare cases, this could lead to hospitalization, although this is unusual unless the milk is very off.
If you think milk has gone off, do not consume it. Throw it away to avoid the risk of getting sick. Even a relatively small amount of off milk could be dangerous, and it doesn’t taste good anyway.
How Do You Know If Milk Has Gone Bad?
It is usually fairly obvious when milk has gone bad, because it produces a sour, unpleasant scent that can be really off-putting. However, there are a few other signs to look out for if you are still unsure, including lumpiness and a sour flavor.
If you think some milk has gone bad but you aren’t sure, the best thing to do is tip it into a cup and inspect it. Bad milk will often have a slightly brown color, flecks of mold on the surface, or lumps in it. It may also have separated a bit.
Note that it does not have to show all of these signs to be off, but it will usually taste bad. It’s safe to taste a small amount if you are unsure, but do so without adding it to a drink so you are able to check properly, without other flavors affecting it.
If in doubt, it is better to throw milk away than to drink it, but usually, it will be reasonably easy to tell when milk is no longer safe to consume.
What Temperature Should Milk Be Kept At?
Milk needs to be kept below 40 degrees F in order to minimize the spread of bacteria. This is why it should be kept in the fridge. Ideally, it should also be kept in the coldest part of your fridge to maximize its lifespan.
Most people place their milk in the door of the fridge for convenient access, but this is not actually the best place to store milk. Instead, milk should be kept as close to the bottom of the fridge as possible in most fridges. Because cold air sinks, this is usually the coldest area.
If you have an ice making compartment at the top of the fridge, it is better to store the milk near to this instead, as this will be colder. The cooler you keep your milk, the better it will last overall.
Does Pasteurized Milk Need to be Refrigerated?
Yes, pasteurized milk does need to be refrigerated, and so does UHT milk once it has been opened. UHT milk has been heated enough to be safely stored at room temperature until it is opened, but once open, it needs to be refrigerated like all other milk.
The milk that you buy from stores will always be pasteurized unless it specifically says otherwise. This is done to kill off bacteria and make the milk safer to drink. However, it does not mean that you should store it on the counter.
Does Sealed Milk Need to be Refrigerated?
Unless you are dealing with UHT milk, which is stable at room temperature while sealed, you still need to put the milk in the fridge as soon as possible. Even when the seal is intact, bacteria can spread through the milk, so don’t leave sealed milk on the counter.
When you buy milk from the grocery store, you should make an effort to minimize the amount of time that it spends at room temperature, even though its seal is intact. Pick it up toward the end of your shopping trip, and then make an effort to get it back into a fridge as soon as possible.
Don’t leave milk sitting in the back of a car for hours. If you know you will not be going directly home, consider taking an insulated bag and an ice pack so that the milk’s temperature is retained until you can get it in the fridge.
Milk should not sit on a counter for more than two hours, or an hour in hot weather. It is important to put milk straight into the fridge when you have finished using it, and to store it in the main body of the fridge, rather than the door. This will help to keep the temperature low and minimize the spread of bacteria.