From hot peppers and root veggies to fresh berries and cherry tomatoes, there is so much amazing produce that flourishes in the summer. Whether you’re growing a garden, participating in a CSA (community-supported agriculture), or shopping at local stores, ‘tis the season to take advantage of nature’s bounty and preserve its freshness for a later date.

If you’re looking for a convenient and healthy way to preserve produce without the time commitment of traditional canning, try freezing food in Mason jars.

Freezing Food Without Losing Flavor

Freezing food in Mason jars is an easy, economical, and environmentally-friendly approach to preserving freshness. Using reusable Mason jars allows you to ditch storing your food in plastic containers or bags, which Harvard Health has linked to health problems such as metabolic disorders and reduced fertility. Plus, using fewer plastic bags means lowering your carbon footprint.

While typically glass is the way to go, we strongly recommend not repurposing off-brand jars for freezing. The jars that hold store-bought goods like jam, olives, and pickles, are generally made of thinner glass than Mason jars, making them more likely to break in the freezer. To ensure safer storage, we recommend using traditional brands such as:

  • Atlas

  • Ball

  • Bernardin

  • Golden Harvest

  • Kerr

  • Kilner

  • Legacy

  • Orchard Road

  • Quattro Stagioni

Best Practices for Freezing Food in Mason Jars

Freezing Mason jars is a great way to extend the life of your summer produce and other food. However, it’s critical you follow a few simple best practices.

  1. Don’t fill Mason jars to the top: Food expands as it freezes. As it expands, pressure can build in the jar and break the glass. For this reason, leave at least one inch of space at the top of the jar to allow for expansion. Wide mouth Mason jars typically include a freeze-fill line on the side for reference.
  2. Use only wide-mouth Mason jars without shoulders: Wide-mouth Mason jars are always better than regular mouth jars when it comes to freezing food. If you’re freezing liquids such as soups or broth, using a wide mouth is even more essential because of expansion.freezer jars
  3. Keep the lid loose, at first: Wait to tighten the lids until the contents in the jar have fully frozen. You’ll want to keep your jars upright while your food is freezing.
  4. Let hot liquids cool: Let your cooked foods cool to room temperature before pouring them into Mason jars. Then, let your filled Mason jars completely cool in the refrigerator before placing them in the freezer. These precautions allow for expansion, so the glass doesn’t shatter.
  5. Leave space between your jars: Don’t let your jars jostle each other and break in the freezer. To avoid broken jars: Consider wrapping fabric around them or place them in a box with dividers. Other ideas: Roll up a sock or cut-up sweatshirt sleeve over your jars to protect the glass.
  6. Let your frozen jars thaw: Before heating up the food inside your Mason jar, let it thaw in the refrigerator overnight. Never place frozen glass in the microwave—it may crack or possibly even explode.

Pro Tips for Beginners

If you’re new to freezing food in Mason jars, that’s okay! We have a few more quick tips that’ll shorten the learning curve.

  • Label your jars: Be sure to write out the type of food in your jars and date them for easy reference later. We recommend using freezer tape for labeling. Unlike regular masking tape, it won’t peel off when frozen. Alternatively, you can write on the lid with a permanent marker and erase it later with rubbing alcohol.

  • Keep your lids together: Use a basket or box to keep your cupboards tidy.

  • Freeze individual foods first: When you’re freezing foods such as berries, vegetables, or meatballs, we recommend freezing them first before placing them in a Mason jar. This step will help ensure they won’t clump together in the freezer. Place a cloth on a large cookie sheet to absorb excess moisture, then freeze these foods in a single layer for at least an hour (up to four hours). Then pour the frozen food into a Mason jar, seal the lid, and put it back in the freezer.

  • Use a funnel: Save yourself some spills and use a funnel when pouring foods into your Mason jars.

Making the Most of Your Mason Jars

Now that you know how to safely freeze food in Mason jars, there are a few more tricks to maximize the benefits of this storage method.

First, you should find ways to buy fresh produce in bulk. Not only will it save you money, but if you buy produce in the summer months, it’ll also be way tastier. Head to your local farmer’s market or a “you-pick” farm and load up.

Another great option is joining a CSA. Think of it as a summer subscription to fresh produce. Should you join a CSA, you’ll receive weekly boxes of fresh, in-season fruits and vegetables. However, your shipment will often contain more produce than you can eat in one week. So, store what’s left in a Mason jar and enjoy it later when fresh fruits and vegetables aren’t as plentiful and easy to come by.

With all this nutritious produce, you should also consider making your own broth and freezing it. You’ll have a tasty base for creating your own winter soups, and you’ll know it isn’t filled with preservatives like store-bought soups often are.

Pre-making breakfast smoothies is also a great way to ensure you’re eating well, even on your busiest mornings. Simply unthaw your Mason jar smoothie the night before and enjoy a delicious meal on the run!

A “Cool” Way to Preserve Your Food

Freezing food in Mason jars is an excellent solution for extending the life of your summer produce, broths, soups, and smoothies (just to name a few). Moreover, it’s an excellent way to lessen waste and lower your individual carbon footprint. For more creative uses for Mason jars, visit our “Get Inspired” Community page and shop our Mason jar accessories