How to Freeze Liquids in Mason Jars | Freezing Milk in Glass Bottles

This post was most recently updated on January 28th, 2021

If you are anything like me, you might like to know how to freeze milk or other liquids without using plastic. If you are wondering can you freeze milk in glass bottles? I have a great solution that you can use to freeze soup, stock, milk or stew in glass, read on to find out more.

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Mason Jars. I am a homesteader. Of course the answer is mason jars, right?

If you have ever bought a milk on sale, or ended up with a surplus from a dairy cow or goat and wondered if you can freeze milk, I am here to tell you that you can!

Even human breast milk can be frozen in mason jars!

RELATED: How to can milk

Freezing milk in mason jars is easy once you know how!

You may realize that freezing liquids in glass has a bad reputation, but I have some tips to help you avoid the disasters!

We currently have my mother’s dairy goat hanging out at our place with our Edith and stinky Freddy the buck.

Hopefully this will mean we will have babies from the girls again later in the season. However, in the meantime I have a lot more goats milk than the odd bowl of cereal can keep up with.

After jumping on the plastic free bandwagon, I am trying to avoid using single use plastic. Or plastic at all, if it is possible.

Mason jars solve many of my plastic free requirements. Including storing food, makeshift lunch boxes, storing leftovers in the fridge and now, freezing liquids.

RELATED: Freezing meat without plastic

Tips for Freezing Breast Milk in Glass Jars

If you are pumping, your expressed breast milk needs a safe, zero waste way of storing it. Storing breast milk in mason jars (or any other glass jar) is a perfect solution!

For safe breastmilk storage you will need to make sure the jars are very clean – you can sterilize them by heating them in the oven at 200F/100C for 15 minutes then allow them to cool.

Pour fresh breastmilk in to your glass jars up to 1 inch below the shoulders of the bottle or jar. You can use a plastic bottle if you do not have a glass jar or bottle.

Place lids that have been boiled for 10-15 minutes on the top, then you can store the jars knowing that they are super clean and ready to add your milk.

Make sure you add the date to the jars before placing them in the freezer. Human milk is amazing stuff and you can keep the jar in the fridge and add to it for 2-3 days before moving it to the freezer.

Frozen breast milk will last in the freezer for 3-6 months in the freezer or 6-12 months in a deep freeze or chest freezer.

Follow the directions below regarding how full to fill the jars and how to defrost them. Once defrosted human breastmilk should be used within 5 days.

If your baby is just needing small volumes of milk at a time, or you want some smaller volumes to mix through solids for weaning, you can freeze the milk in ice cube trays, once the milk is frozen you can move it in to a storage bags, a freezer bag or sealed glass jar to store in the freezer.

Can you freeze milk in glass bottles?

The simple answer is yes. But it depends. You can freeze milk in glass bottles if you follow the tips below.

Another alternative to using glass to freeze milk is to invest in some reusable silicone freezer bags. These are perfect for freezing liquids in without the risk of them smashing, and they do stack better than mason jars or glass bottles do in the freezer.

I own and love these bags here, but there are many for you to choose from these days!

The risk of freezing liquids like milk or soup in glass is that liquids expand when they freeze.

This means that if you over fill the jars they will crack. This leaves you with both a big mess, ruined food and a wasted jar.

Not ideal.

What Liquids are Suitable for Freezing in Glass Jars or Bottles?

Basically any liquid that you want frozen can be frozen in glass jars or bottles if you do it correctly. Almond milk, soy milk, breastmilk, cow milk, cream and oat milk are all good choices.

Other common choices are excess goat milk, bone broth, stock, soups and stews. Pureed fruit also needs to be frozen following this method, anything that is sloppy or runny needs to be frozen carefully so as to not shatter the jars.

How do you freeze milk in a mason jar?

1) Use wide mouth jars and bottles

2) Keep the liquid an inch (2.5cm) below the shoulders of the jar.

These jars were filled to the same level. The one on the right is frozen.

Wide mouth jars have very little, if any, shoulder to the shape of the jar. The shoulder of the jar is where the wide bit starts to get narrow. It is also the area most likely to break when you are using glass to freeze things.

As the jar contents is freezing it will freeze from the outside inward. This means the piece of liquid sitting under the shoulders will be solid fairly near the beginning of the freezing process.

As the inside of the liquid freezes it pushes back against the outer layer that is already frozen, expanding the liquid upwards towards the space that you have left for it.

If there is not enough space below the shoulders, as the ice is forced straight up it will push right through the glass in it’s way causing it to crack.

So, to ensure that you don’t crack all your jars, keep your liquid at least 1 inch below the shoulders of the jar.

Better yet try and get wide mouth jars that have very little shoulder.

Another option are glass flat dishes with re-usable lids like these. They are great as they are able to be stacked in your freezer. While they are not totally plastic free, they are very high quality and will last you a very long time.

Remember to label and date your jars so you know what is in there and what to use first!

Tips for Freezing Gallons of milk

If your milk is already in a plastic gallon bottle, you can freeze it by following these tips:

1. Leave the jug of milk sealed

This stops the air affecting the milk while it is in the freezer.

2. Shake the milk bottle very well before placing it in the freezer

This helps keep the milk from splitting when you thaw it. Sounds crazy I know, but it helps!

Thawing Frozen Milk so it doesn’t Split

Frozen milk has a tendency to split when you defrost it. To help reduce that, follow these tips:

Place the milk to defrost at room temperature on a tea towel
Shake the bottle well every hour or so until thawed
Once thawed, place in the fridge

If you milk does split, it is still perfectly fine to drink, or use it in baking or making bread. You can use a nutribullet to blitz split milk and it will re-emulsify it.

Does freezing milk change the taste?

Once milk has been frozen in glass and defrosted again at room temperature, it should taste the same as the milk that went in to the freezer.

As long as your milk has not been affected by freezer burn, it should not alter the flavor at all having been frozen.

How long can I keep milk in the freezer?

Milk will freeze well in the freezer, but how long it lasts in the freezer does depend on several factors:

1) How fresh the milk was – the more fresh the milk was before you placed it in the freezer, the longer it will keep in there.

2) How cold your freezer is – milk in a normal upright freezer will last about 3 months, milk stored in a deep freeze will last 6-12 months

3) What you store the milk in – milk stored in glass will be less likely to develop freezer burn. Milk stored in thin plastic are more likely to get a small hole in the plastic and get exposed to the dry freezer air. If the milk is exposed to the air it will develop freezer burn much more quickly.

Can you use milk that was freezer burned?

The short answer is yes, however, milk that was affected by freezer burn will not be nice to drink as it is because freezer burn affects the flavor of the milk. However, you can use freezer burned defrosted milk in baking or cooking.

Can you freeze milk in ziploc bags?

Ziploc bags can be used to store milk for short term storage of milk in the freezer, however, the milk will slowly rub holes in the corners of the bags as they get jostled around in the deep freeze and this will allow the air to get in to the bags meaning it is much more likely to be affected by freezer burn.

Also, when you defrost your milk that have been kept in a ziploc bag, be sure to sit it in a bowl or jug as the bag will leak.

How long can a glass bottle stay in the freezer?

Glass itself can stay in the freezer forever without a problem. However, the products inside the freezer should be consumed within 3-6 months in an upright freezer and within 12 months in a deep freeze.

How long does frozen milk last after thawed?

How long your milk lasts after you defrost it depends on two things, how close to expiring it was before you froze it, and how well it has survived the freezing process.

If your milk is 5 minutes away from expiring before you put it in the freezer, then your thawed milk will have about 4 minutes left once it defrosts.

If your milk was fresh when it went in to the freezer and it has no sign of freezer burn, it will last as long as it would have as if it hadn’t spent time in the freezer. If it usually would last you a week, then you have about a week before it goes off after you defrost it.

Freezing Milk in Glass Bottles in Conclusion

So there you go, you CAN store your soups, stews, stocks and spare milk in the freezer without using plastic. Freezing liquids in glass ain’t so tricky after all. Follow these simple steps to ensure your glass bottles of milk or other liquids don’t crack and they freeze for a long time.