Milk is one of those groceries that even though you need it for a lot of recipes, it can be hard to use up before the expiration date. This dilemma begs the question: "Is milk save to freeze?" The short answer is, yes, you can absolutely freeze milk. To be safe, there are some guidelines you should follow before doing so.
First of all, it's important to note that depending on what kind of milk you're freezing, it will react differently to the process. Most milks will separate when frozen, but almond and oat milks will become particularly grainy in texture, according to Healthline. Other milks that typically come in cans, like coconut or condensed milk, should not be frozen while in the cans, because they'll need room to expand.
To best prepare your milk for freezing, you should put it in an airtight, freezer-safe bag or container. Don't leave too much air inside of the container, but leave just enough room for it to expand (about 1.5 inches, if possible).
Once you want to defrost and use the milk again, let it do so in the fridge rather than at room temperature, because that puts it at risk for harboring bacteria. If bacteria grows in the defrosted milk, it can be harmful when consumed. Also, be aware that once it unfreezes, the milk likely won't be the exact same consistency it was before.
For this reason, milk that's been frozen should be used for cooking or in smoothies and other recipes that blend it well with other ingredients. If you really want to drink the milk straight rather than cooking with it, you can run it through the blender to try and restore its texture and consistency.
If you're cooking with the milk in a hot pan or pot, the milk can be defrosted straight in the pan. If you tend to use your frozen milk in smoothies, you can separate it into ice trays prior to freezing so you can easily take out only as much as you'll be using.
All of this is to say that yes, you can totally freeze milk if you have to, but try your best to use it within a month of putting it in the freezer. Just make sure you are extra thorough with the process to ensure the best results in your cooking and for your own safety, got it? Good.