Vacuum sealing mason jars works with a standard vacuum sealer and a special adapter, or with a hand pump designed for jars
You can vacuum seal mason jars using one of two methods: a vacuum sealer with a jar attachment, or a hand pump vacuum sealer made specifically for jars. The vacuum sealer method is faster if you are processing many jars at once. The hand pump method costs less upfront and works without electricity, but takes more physical effort per jar. Both remove air and create a seal that keeps food fresher longer than an open jar, though neither produces the same shelf-stable result as pressure canning.
The key difference from regular vacuum sealing is that you cannot use the heat-seal strip on a jar's mouth — the lid must stay removable so you can open and reseal the jar later. What you are doing is removing oxygen to slow spoilage and oxidation, not creating a permanent food-preservation seal. If you want true long-term storage (months or years), pressure canning is the correct method. Vacuum sealing jars is best for pantry items, dry goods, and refrigerated foods you plan to use within weeks.
Key Takeaways
- A vacuum sealer with a jar attachment (sold separately for most models) lets you seal mason jars in seconds by drawing air out through the lid.
- Hand pump vacuum sealers cost $15 to $40 and work on any standard mason jar without needing a special attachment.
- You need a two-piece mason jar lid (flat lid and band), and the flat lid must be new or in good condition for the seal to hold.
- Vacuum-sealed jars stay fresher in the pantry or fridge but are not shelf-stable like pressure-canned food and should be opened and resealed if you break the vacuum.
Using a vacuum sealer with a jar attachment
Most full-size vacuum sealers (brands like FoodSaver, Nesco, and Oster) sell jar attachment kits separately for $15 to $30. The attachment is a tube or nozzle that fits over the vacuum port on your sealer. To use it, place a new or like-new flat mason jar lid on top of the jar (do not screw the band down yet), fit the attachment over the lid's center hole, and press the vacuum button. The sealer draws air out through the lid, and when the vacuum is complete, it stops automatically.
The entire process takes 5 to 15 seconds per jar, depending on the jar size and how much air is inside. After the vacuum cycle ends, remove the attachment and screw the band down by hand — snug but not tight. The lid will have a slight dome or curve inward if the seal worked. Store the jar at room temperature (for dry goods) or in the refrigerator (for foods that need cold storage).
Check the jar's manual or the sealer's website to confirm your model supports jar sealing, because not all do. Some older or budget models lack the suction power needed. If your sealer does not have a jar attachment available, a hand pump is your alternative.
Using a hand pump vacuum sealer for jars
Hand pump sealers are standalone devices that cost $15 to $40 and work on any standard mason jar. Popular brands include Nesco, Foodsaver, and Oster, though many generic versions exist. The pump sits on top of the jar lid and has a handle you push down repeatedly to draw air out. Most hand pumps remove air in 10 to 20 strokes, depending on jar size.
To use one, place a new flat lid on the jar (band not yet tightened), set the pump on top, and push the handle down and pull it back up in a steady rhythm. You will feel resistance increase as the air comes out. When you can no longer push the handle down easily, the jar is under vacuum. Remove the pump and screw the band down by hand. The lid should dome inward slightly, just as with a sealer attachment.
Hand pumps are slower than electric sealers if you have many jars, but they require no electricity and are less expensive. They also work on jars of any size, whereas some sealer attachments are sized for specific jar diameters (usually quart or pint). If you plan to seal jars only occasionally, a hand pump is often the better choice.
Choosing the right mason jar lids
You must use a two-piece lid system: a flat lid (the part that seals) and a screw band (the metal ring that holds it down). The flat lid is the critical piece — it must be new or in excellent condition with no dents, warping, or previous use. Once a flat lid has been used and removed, the seal compound (the rubber-like coating on the underside) is compromised and will not hold a vacuum seal.
Screw bands can be reused indefinitely as long as they are not rusted or bent. If you are buying lids, purchase a box of flat lids only (they are sold separately from bands). Standard mason jar sizes are pint (16 oz), quart (32 oz), and half-gallon (64 oz), and lids are sized to match. A pint lid will not seal a quart jar properly.
Do not use one-piece lids (the old-fashioned kind with the seal compound built in) or plastic lids — neither will hold a vacuum seal. If you are unsure what you have, look at the lid from underneath: a two-piece system has a separate rubber ring or coating on the flat lid, while a one-piece lid has the seal material molded into the lid itself.
What foods work best in vacuum-sealed jars
Vacuum sealing works well for dry goods that do not need refrigeration: flour, sugar, coffee, tea, nuts, dried fruit, cereal, crackers, and spices. It also works for items stored in the refrigerator or freezer, such as leftover soups, cooked grains, or marinated meats. The vacuum removes oxygen, which slows mold growth, rancidity, and flavor loss.
Do not vacuum seal soft breads, cakes, or anything with a delicate texture — the vacuum will crush them. Avoid raw vegetables or fruits with high water content unless you plan to use them within a few days; the vacuum can cause them to release liquid and become mushy. Do not use vacuum-sealed jars for foods that require pressure canning (low-acid foods like beans, meats, or vegetables) — vacuum sealing does not reach the temperature needed to kill botulism spores.
How long vacuum-sealed jars stay fresh
The shelf life depends on what is inside and where you store it. Dry goods in a vacuum-sealed jar at room temperature typically stay fresh 50 to 100 percent longer than in an open container — often several months to a year, depending on the item. Coffee, for example, may stay fresh for 6 to 12 months in a vacuum-sealed jar in a cool, dark cupboard, versus 2 to 4 weeks in an open bag.
Refrigerated foods in vacuum-sealed jars last longer than in regular containers because the vacuum slows bacterial growth, but they still follow normal refrigerator timelines. Cooked soup might last 5 to 7 days instead of 3 to 4. Frozen foods in vacuum-sealed jars can last months, though freezer burn is still possible if the seal breaks or air leaks in over time.
Check the jar regularly for signs the seal has failed: the lid will no longer dome inward, or you will see condensation inside. If the seal breaks, open the jar, remove the old flat lid, and reseal it with a new one if you want to restore the vacuum. Do not assume a jar with a broken seal is spoiled — use your senses (smell, look, taste a small amount) to decide whether the food is still good.
Troubleshooting common sealing problems
If the lid will not seal, the most common cause is a defective or reused flat lid. Replace it with a new one and try again. If you are using a hand pump, you may not have removed enough air — pump longer and more firmly. If you are using a sealer attachment, make sure the attachment is seated properly on the lid and that the sealer itself has enough suction power (test it on a regular vacuum-seal bag first).
If the seal holds initially but breaks within hours or days, the jar may have a chip or crack on the rim where the lid sits. Inspect the rim under good light and feel it with your fingertip. Even a tiny imperfection will prevent an airtight seal. If the jar is damaged, use it for storage without sealing, or discard it.
If the lid domes inward but you can easily pull it off by hand, the seal is weak. This usually means the flat lid was already compromised before sealing. Always start with a brand-new flat lid. If you are certain the lid was new and the seal is still weak, the jar rim may be dirty — wash and dry the jar thoroughly and try again with a fresh lid.
Frequently Asked Questions
Can I vacuum seal a mason jar without buying an attachment or hand pump?
No. A regular vacuum sealer bag has a heat-seal strip that closes the bag permanently, which does not work on a jar. You need either a jar attachment for your sealer or a hand pump designed for jars. Both are inexpensive ($15 to $40) and widely available online and in kitchen supply stores.
Will vacuum-sealed jars last as long as pressure-canned jars?
No. Pressure canning heats food to a temperature that kills bacteria and creates a permanent seal that can last years. Vacuum sealing removes air but does not heat the food, so it is best for items you plan to use within weeks or months. For long-term pantry storage (a year or more), pressure canning is the correct method.
Do I need to refrigerate vacuum-sealed jars?
It depends on what is inside. Dry goods (flour, coffee, nuts) can stay at room temperature in a cool, dark cupboard. Foods that normally need refrigeration (cooked meals, dairy, meat) should still be refrigerated in a vacuum-sealed jar. The vacuum extends shelf life but does not make perishable foods shelf-stable.
Can I reuse the flat lid if I open a vacuum-sealed jar?
No. Once a flat lid is removed, the seal compound is damaged and will not hold a vacuum seal again. You must use a new flat lid each time you want to reseal a jar. Screw bands can be reused as many times as you want.
What is the difference between vacuum sealing jars and canning?
Vacuum sealing removes air to slow spoilage and keeps food fresher longer, but the jar is not shelf-stable and must be opened and resealed if the vacuum breaks. Canning (especially pressure canning) heats food to kill bacteria, creates a permanent seal, and produces shelf-stable jars that last years without refrigeration. Vacuum sealing is faster and easier for short-term storage; canning is for long-term preservation.