How To Vacuum Seal Mason Jars

Learning how to vacuum seal mason jars is a fantastic skill for any home preserver. It’s a simple method that extends the shelf life of your dry goods, leftovers, and even freezer meals by removing air, the main culprit behind spoilage. This guide will walk you through everything you need to know, from the tools required to step-by-step instructions for different methods.

You might already be familiar with using mason jars for canning with a water bath or pressure canner. Vacuum sealing is different. Instead of creating a seal through heat, you’re mechanically removing the air from the jar. This creates an environment where bacteria, mold, and yeast struggle to grow. It’s perfect for items that don’t require the high-heat processing of traditional canning.

Before you start, it’s important to gather the right equipment. You don’t necessarily need a expensive machine to get started. Here are the common tools used for this process.

Essential Tools and Equipment

Mason Jars: Use genuine Ball, Kerr, or other branded mason jars. They are specifically designed to withstand pressure. Always check for chips or cracks in the glass or the rim.
Lids and Bands: You have two main options: standard two-piece lids (flat disc and screw band) or special vacuum sealing lids. The flat disc on two-piece lids can often be reused for vacuum sealing if they are in perfect condition.
Vacuum Sealer Machine with Jar Attachment: This is the most reliable tool. A food vacuum sealer, often used with bags, can be adapted for jars with a special hose and lid attachment. This creates a very strong, consistent vacuum.
Hand-Pump Vacuum Sealers: These are affordable, manual pumps that work with special plastic lids. They are great for occasional use but may not create as strong a seal as an electric machine.
Water Displacement Method: This low-tech option requires no special equipment beyond your jars and lids. It uses hot water to create a partial vacuum as the contents cool.

Preparing Your Jars and Contents

Proper preparation is key to a successful seal. Always start with clean jars. Wash them in hot, soapy water and rinse well. You can also run them through a dishwasher cycle. Ensure they are completely dry if you are storing dry goods, as moisture can lead to clumping or spoilage.

For the best results, your food items should be prepared appropriately. Dry goods like flour, rice, beans, and pasta should be at room temperature. For freezer storage, allow hot foods to cool completely before sealing to prevent ice crystals and frost inside the jar. Leave adequate headspace—about 1 to 1.5 inches from the rim—to allow the vacuum to form properly.

Method 1: Using a Vacuum Sealer Machine

This method offers the strongest and most consistent vacuum. It’s ideal for long-term storage of dry goods or for creating airtight seals for items going into the freezer.

Attach the hose from your vacuum sealer to the machine’s port and to the special jar sealer lid.
Fill your clean, dry mason jar with your food, leaving headspace. Wipe the jar’s rim clean to ensure no debris interferes with the seal.
Place the special vacuum sealing lid (or a new, clean standard flat lid) on the jar. Screw a band on fingertip-tight—just until you feel resistance.
Place the jar sealer attachment on top of the lid. Turn on your vacuum sealer and activate the jar-sealing function, or manually start the vacuum process.
You will hear the machine pull the air out. Once the vacuum is complete, the machine will stop. The lid will be sucked down, creating a concave shape. The seal is now complete.
Remove the attachment. You can store the jar with or without the screw band. The vacuum pressure is what keeps the lid securely in place.

Method 2: Using a Hand Pump

Hand pump systems are a great budget-friendly choice. They typically come with special plastic lids that have a built-in valve.

Fill your jar as usual, leaving headspace. Wipe the rim clean.
Place the special plastic lid with its rubber gasket onto the jar. Screw the included band on firmly.
Attach the hand pump to the valve on the lid.
Pump the handle repeatedly. You’ll feel resistance increase and see the lid pull down as the air is removed.
Once you cannot pump anymore, detach the pump. The valve will close, locking the vacuum in place.

Method 3: The Water Displacement Trick

This is a clever, no-equipment method that works well for foods you plan to refrigerate or freeze relatively quickly, like soups, stews, or chopped vegetables. It creates a good, but not as strong, partial vacuum.

Fill your jar with the food you want to store. For this method, it’s best to use hot or very warm food. Leave about 1 to 1.5 inches of headspace.
Slowly pour hot water (or the hot liquid from your food) into the jar, filling it to within a half-inch of the rim, submerging the solid contents.
Take a clean utensil, like a chopstick, and slide it down the inside of the jar to release any air bubbles trapped in the food.
Wipe the jar’s rim perfectly clean. Place a new, clean flat canning lid on top. Screw a band on fingertip-tight.
As the hot contents cool down in the refrigerator or freezer, they contract. This creates a vacuum that will pull the lid down, resulting in a concave center. You’ll hear a “pop” as it seals.

Testing Your Seal

No matter which method you use, always test the seal before storing your jars long-term. After the jar has cooled or the vacuum process is complete, press down on the center of the lid. It should not move up or down at all. If it flexes or makes a clicking sound, the seal failed. For a visual check, the lid should be curved slightly inward. You can also try lifting the jar by just the lid (gently and over a soft surface); a proper vacuum seal will hold the weight.

What Can You Vacuum Seal in Mason Jars?

The possibilities are nearly endless! Here are some of the best items to preserve using this technique.

Dry Pantry Staples: Flour, sugar, rice, pasta, beans, lentils, coffee beans, tea leaves, powdered milk, and dehydrated fruits/vegetables. This protects them from moisture, pests, and staleness.
Snacks: Crackers, chips, nuts, seeds, and pretzels stay crispy much longer.
Leftovers: Portion out soups, sauces, stews, casseroles, or chopped meats for easy fridge or freezer meals.
Fresh Produce: Berries, chopped onions, peppers, and herbs can be frozen without getting freezer burn. Some people use vacuum sealing for fermenting vegetables like sauerkraut, as it creates an anaerobic environment.
Other Goods: It’s not just for food! Protect important documents, photographs, or survival kit items like matches from humidity.

Common Mistakes to Avoid

Even with a simple process, errors can happen. Avoid these common pitfalls to ensure your seals are secure and your food stays safe.

Using Damaged Jars or Lids: A single chip on the sealing surface of the jar rim will prevent an airtight seal. Always inspect your equipment. Dented or rusty bands can also cause problems.
Overfilling the Jar: Not leaving enough headspace prevents the vacuum from forming correctly. Food particles can also get caught on the rim and break the seal.
Overtightening the Band: Screwing the band on too tightly can actually warp the lid or jar rim, preventing the vacuum from pulling the lid down properly. Fingertip-tight is the rule.
Sealing Hot, Wet Foods for the Pantry: Vacuum sealing moist foods at room temperature creates a risk for botulism, a dangerous form of food poisoning. Moist, low-acid foods sealed without proper heat processing belong in the refrigerator or freezer only.
Ignoring a Failed Seal: If a lid doesn’t pop down, don’t just put it in storage. Consume that food quickly or reseal it using a new lid.

Benefits of Vacuum Sealing with Jars

Why choose jars over plastic bags? There are several compelling advantages that make this method worth learning.

Zero Waste & Reusable: Mason jars are glass and can be washed and reused indefinately, unlike single-use plastic bags. This is a much more sustainable option.
No Chemical Leaching: Glass is inert and won’t leach chemicals into your food, especially when storing acidic or fatty items.
Stackable and Visible: Jars are easy to organize in your pantry or freezer. You can immediately see what’s inside and how much is left, reducing food waste.
Stronger Seal for Long-Term Storage: A properly vacuum-sealed jar can keep dry goods fresh for years, far longer than plastic containers or bags, which can slowly allow air to permeate.
Multi-Purpose: The same jars can be used for canning, dry storage, drinking glasses, or food prep. It’s a versatile kitchen investment.

Frequently Asked Questions (FAQ)

Can you vacuum seal any mason jar?

You should only use jars specifically made for home canning, like Ball or Kerr mason jars. These are tempered to handle the pressure of a vacuum. Old pasta sauce jars or other commercial glass containers are not designed for this and could crack or shatter under the pressure.

Do you need special lids to vacuum seal mason jars?

It depends on your method. For a vacuum sealer machine, you can often use new, standard flat canning lids with the attachment. Hand-pump systems require their own proprietary plastic lids. The water displacement method works with standard two-piece canning lids.

How long does vacuum-sealed food last?

It varies greatly by the food. Dry goods like rice or beans can last for years in a cool, dark pantry. In the freezer, meats and prepared meals can last 2-3 years without freezer burn. In the refrigerator, leftovers typically last 3-4 times longer than in a regular container—up to 2-3 weeks for many items.

Is vacuum sealing in jars as good as canning?

No, they are completely different processes with different safety purposes. Canning uses high heat to destroy pathogens and create a sterile, shelf-stable seal for moist foods. Vacuum sealing only removes air; it does not kill bacteria. It is not a safe substitute for canning wet foods you plan to store at room temperature.

Can you reuse the flat lids for vacuum sealing?

Yes, you can often reuse the flat metal lids for vacuum sealing, as long as they are not bent and the sealing compound is intact and clean. However, for actual water bath or pressure canning, you must always use brand new lids to guarantee a safe seal.

Why did my jar lose its vacuum?

A broken vacuum can happen for a few reasons. The food might have off-gassed (released natural gases), especially with fresh produce. There could be a micro-fracture in the jar or an imperfection on the lid’s sealing surface. A significant temperature change can also sometimes break a weak seal. Always inspect jars before using the contents.

Mastering how to vacuum seal mason jars opens up a world of efficient, sustainable food storage. It reduces waste, saves money, and keeps your food fresher for longer. Start with the simple water displacement method for your next batch of soup, or invest in a basic hand pump for your pantry staples. With a little practice, you’ll find this technique becomes an essential part of your kitchen routine, helping you preserve the abundance from your garden, a great sale at the market, or simply your weekly leftovers with confidence and ease.