How to Use a Vacuum Sealer (Step by Step, Plus What Not to Seal)

The most important fact about a vacuum sealer isn’t printed on the box: it doesn’t preserve food on its own. It removes air, which slows freezer burn, staleness and the mold and bacteria that need oxygen. Your fridge and freezer still do the actual preserving.

How to use a vacuum sealer, in short: cut a bag with 3 inches of empty space above the food, keep the opening clean and dry, lay the open end flat across the sealing strip, pick the dry or moist setting, close the lid and press vacuum and seal. Freeze anything wet or soft for an hour or two first. Then label it and get it straight into the fridge or freezer.

That covers most of it. The rest of this guide explains the details that make the difference between a seal that holds for months and one that leaks in the freezer by Tuesday, and it covers the short list of foods that should never be sealed at all.

How to Use a Vacuum Sealer, Step by Step

These steps are written for the common countertop “edge” sealer, such as most FoodSaver, Nesco and Anova models. The bag’s open end sits outside the machine, a small pump pulls the air out, and a heated strip melts the bag closed. Your model’s buttons may be labeled differently, so skim your manual once, but the process is the same.

1. Prepare the food

Pat meat and fish dry with paper towels. Portion food the way you’ll actually cook it: two chicken breasts per bag if you cook for two, one steak if you cook for one. America’s Test Kitchen recommends sealing only what you’ll use at one time, since a sealed bag can’t be opened and resealed without cutting more off the top.

Soft, juicy or wet foods need a trip to the freezer first. There’s a whole section on pre-freezing below.

2. Label the bag before you fill it

This seems minor until you try writing on a lumpy frozen bag. America’s Test Kitchen suggests labeling bags while they’re still empty and flat. Write what it is and the date. A permanent marker works on most textured bags.

3. Cut a bag with enough headroom

If you’re using a roll, pull out enough to fit the food plus extra length, then seal one end to make a pouch. FoodSaver’s owner’s manual for its FM5200 and FM5300 series says to leave 3 inches between the food and the top of the bag. If you plan to wash and reuse the bag, add at least 1 more inch per reuse, because each seal trims a strip off.

Pre-cut quart and gallon bags work the same way. Just don’t overfill them.

4. Fold a cuff to keep the opening clean

Fold the top 2 to 3 inches of the bag outward, like a sock cuff, before you load the food. America’s Test Kitchen calls this one of the three keys to better vacuum sealing: it keeps meat juice, marinade and grease off the part of the bag that needs to fuse. Unfold the cuff once the food is in.

5. Lay the bag flat and choose your setting

Spread the food into an even, flat layer. Flat packs freeze faster, thaw faster and stack neatly. Place the open end of the bag across the sealing strip and into the vacuum channel or drip tray, with no wrinkles.

Most sealers have a dry and a moist setting. Use dry for things like cheese blocks, homemade bread or nuts. Use moist for marinated meat or anything with surface moisture; it adjusts the seal so it can fuse through slightly damp plastic. Some models also have a gentle or pulse mode for crushable food like chips or berries, which lets you stop the vacuum before it flattens everything.

6. Vacuum and seal

Close and lock the lid, then press vacuum and seal. The pump runs until the bag pulls tight, then the heating strip seals it automatically. For delicate food, use pulse or press the seal button early to stop the vacuum at the right moment.

Check the seal before you move on. It should be a clear, continuous line with no creases, bubbles or gaps.

7. Let the machine rest between bags

The heating strip gets hot. FoodSaver’s manual says to wait 20 seconds between seals so the appliance can cool. Sealing bag after bag without a pause is a common cause of weak, melted or wrinkled seals.

8. Store it right away

Perishable food goes straight into the fridge or freezer. Freeze flat packs on a sheet pan first, then stand them up like files once they’re solid. That trick alone saves a lot of freezer space.

Pre-Freezing: The Step That Fixes Most Problems

A vacuum sealer pulls hard. Anything soft gets crushed, and anything wet gets drawn toward the pump, which ruins the seal and can damage the machine. The fix is to firm things up in the freezer first.

FoodSaver’s manual gives these pre-freeze times:

Food	What to do first	Pre-freeze time
Raw meat and fish	Pat dry, portion, freeze on a tray or in an open bag	1 to 2 hours
Soft fruit and berries	Spread on a tray so they don’t clump	1 to 2 hours, until solid
Bread, cakes and muffins	Freeze if using bags, or use a canister instead	1 to 2 hours
Soup, stock, sauce, chili	Freeze in a bag set in a loaf pan or container	Until completely firm
Raw vegetables	Blanch, chill in ice water, dry, then freeze	Until firm
Dry goods (rice, nuts, crackers)	No pre-freezing needed	None

America’s Test Kitchen also recommends partially freezing fragile food like fish fillets and berries for a couple of hours before sealing so they keep their shape.

How to Vacuum Seal Liquids and Soup

This is where most people run into trouble with an edge sealer. Even a spoonful of broth will get sucked toward the sealing strip.

The method America’s Test Kitchen recommends:

1. Set an open vacuum bag inside a loaf pan or a straight-sided container and fold the top over the rim.
2. Ladle in cooled soup, stock or sauce.
3. Freeze until firm.
4. Lift the frozen block out of the pan and vacuum seal it like any solid food.

You end up with neat, brick-shaped portions that stack well. If you seal liquids often, a chamber vacuum sealer is worth a look, because it vacuums the whole bag inside a chamber and can seal liquids without freezing them first. It’s larger and more expensive, though.

Marinades are a gray area. Some sealers come with a marinating canister, and FoodSaver models with an accessory port can vacuum a canister directly. That’s the easier route for marinating than trying to vacuum a bag full of liquid.

Bones, Sharp Edges and Crumbly Food

Bony cuts

Chop bones, rib tips, T-bones and crab legs can poke straight through a bag when it pulls tight, or later in the freezer. America’s Test Kitchen suggests laying a piece of parchment paper over the bones and wrapping it in place with plastic wrap to blunt them. FoodSaver’s manual gives similar advice: cushion sharp items with paper towels.

Powders, coffee and flour

Fine powders can get pulled into the pump. FoodSaver recommends placing a coffee filter or folded paper towel inside the top of the bag, above the food, as a barrier. The other option is to leave powders in their original bag and seal that inside a vacuum bag.

Crushable snacks

Chips, crackers and home-baked cookies need the pulse or gentle setting, or a canister. Stop the vacuum as soon as the bag hugs the food.

Vacuum Sealing Does Not Make Food Shelf-Stable

This part matters more than any technique.

Taking the air out of a bag slows the bacteria and mold that need oxygen, which is why vacuum-sealed food keeps its quality longer. But some dangerous bacteria grow best without oxygen. The one food safety experts worry about most is Clostridium botulinum, which causes botulism.

The University of Connecticut’s extension service explains the risk plainly: food with botulism toxin “can look, smell and taste perfectly fine.” North Carolina State Extension adds that the organism grows best at room temperature in low-acid, moist foods in low-oxygen conditions, which describes a sealed bag of cooked chicken on the counter very well.

So these rules apply to every sealed bag:

• Keep perishable food cold. FoodSaver’s manual says to keep vacuum-sealed perishables at 40°F or below and states that vacuum sealing “is NOT a substitute for refrigeration or freezing.”
• Two hours, maximum. NC State Extension says vacuum-packed perishable food should not be out of refrigeration for more than 2 hours total above 40°F.
• Freezer at 0°F or colder. UConn’s guidance for frozen vacuum-packed food is to store it at 0°F or below.
• Only dry foods at room temperature. Crackers, rice, dried fruit, nuts and jerky can be vacuum sealed and kept in the pantry because they have too little moisture to support bacterial growth.
• It is not canning. Vacuum sealing is not a substitute for the heat processing that home-canned foods need.

The same food safety habits still apply before sealing: clean hands, clean cutting boards and knives, and meat cooked to a safe internal temperature later. A good meat thermometer takes the guesswork out, and here’s how to clean a meat thermometer so it doesn’t spread bacteria between foods.

What Not to Vacuum Seal

Here is the short list, with the reason for each.

Food	Why it’s a problem	What to do instead
Soft cheeses (brie, ricotta, fresh cheeses)	FoodSaver’s manual lists them among foods that should never be vacuum sealed, due to anaerobic bacteria risk	Wrap in cheese paper or store in a container
Fresh mushrooms	Listed as never-seal in FoodSaver’s manual	Store loosely in a paper bag in the fridge
Fresh onions and garlic	Listed as never-seal in FoodSaver’s manual; low-acid and a known botulism concern	Keep whole in a cool, dry, airy spot
Raw vegetables for the freezer	Enzymes keep working, which dulls color, flavor and texture	Blanch, chill, dry, then seal and freeze
Moist, low-acid cooked dishes (chili, stews, mushroom soup)	Unsafe at room temperature in a sealed bag	Seal, then refrigerate or freeze only
Home-canned food	Sealing doesn’t replace heat processing	Follow tested canning instructions

FoodSaver’s manual gives blanching times of 1 to 11 minutes depending on the vegetable. FoodSaver also publishes a separate guide just for broccoli and other cruciferous vegetables, so give those extra care. Potatoes are another vegetable people often want to seal raw; our guide to how long potatoes last covers better ways to store them.

A note on cream cheese: it’s soft, so it falls into the risky group for sealing and fridge storage. If you’re trying to stretch a block, freezing is the better approach, and our guide on whether you can freeze cream cheese covers what happens to the texture.

How to Thaw Vacuum-Sealed Food Safely

Thaw in the fridge, not on the counter. UConn’s extension guidance is to open the package when you take it out of the freezer, allowing some air in, and then thaw it in the refrigerator. NC State Extension says the same: thaw in the fridge and remove or open the vacuum bag while it thaws.

This matters most for fish. Michigan State University Extension specifically advises opening vacuum-packed fish before thawing it. If you fillet your own catch before freezing, an electric fillet knife makes quick work of it, and flat, boneless fillets seal far more reliably than whole fish.

If you’re cooking sous vide, you’ll cook straight from the sealed bag instead, which is a different process with its own time and temperature rules. Our guide to the best sous vide precision cookers explains how that works.

Bags, Rolls and Types of Sealer

Textured bags vs smooth bags

Edge sealers need textured (embossed or channeled) bags. The tiny ridges give air a path out while the pump runs. Packaging supplier JVR Industries notes that these bags are typically around 4 mil thick, while smooth chamber pouches are usually about 3 mil and cost much less per bag.

Smooth chamber pouches won’t evacuate properly in an edge sealer. If your seals keep failing and you bought bargain bags, check that they’re textured.

Rolls are cheaper per bag and let you size each pouch to the food. Pre-cut bags save time. You can find FoodSaver-compatible bag rolls from many brands; just match the roll width to your machine.

Which kind of sealer do you have?

Type	How it works	Good at	Weak spots
Edge (external) sealer	Bag end sits outside; pump pulls air through the channels	Meat, cheese, dry goods, freezer prep	Liquids, needs textured bags
Chamber sealer	Whole bag goes inside a sealed chamber	Liquids, marinades, heavy use, cheap bags	Big, heavy and expensive
Handheld sealer	Small pump draws air through a valve on zipper bags	Quick jobs, small kitchens	Weaker vacuum, special bags only

If you’re still choosing a machine, our roundup of the best vacuum sealers for sous vide compares popular edge and chamber models.

Reusing bags

You can wash and reuse bags that held dry food, bread or produce, as long as you left extra length when you first cut them. Bags that held raw meat, fish or greasy food are hard to get properly clean, so many cooks simply throw those away.

When the Seal Fails: Quick Fixes

Problem	Likely cause	Fix
Bag won’t pull tight	Bag not flat in the vacuum channel, or a smooth bag	Reposition with no wrinkles; use textured bags
Seal has gaps or creases	Wrinkled plastic across the strip	Flatten the bag mouth before closing the lid
Seal looks fine but air creeps back in	Moisture or grease in the seal area, or a pinhole	Fold a cuff next time; check for bone punctures; reseal above the first seal
Liquid gets sucked into the machine	Wet food not frozen	Pre-freeze; clean the drip tray
Seal is melted or weak after several bags	Heating strip too hot	Wait 20 seconds between seals
Food is crushed	Full vacuum on soft food	Use pulse or gentle mode, or pre-freeze

Many owners also add a second seal a little above the first on bags going into long-term freezer storage. It costs half an inch of plastic and gives you a backup if one seal has a weak spot.

Getting the Most From It in a Small Kitchen

A vacuum sealer is one more appliance on a crowded counter, so it should earn its place. It does that best when you buy in bulk, cook in batches or freeze a lot.

• Batch cook and freeze flat. Cook once, portion, seal and freeze flat. These easy meal prep ideas for one person pair well with a sealer.
• Slice and seal deli meat or roasts. If you cook a big roast or buy whole salami, a meat slicer turns it into thin portions that seal flat and thaw in minutes.
• Split family packs. Buy the large pack of chicken, split it into single portions and freeze them. Our guide to how much a chicken breast weighs helps you portion evenly, and how long chicken lasts in the fridge tells you how fast to get it sealed.
• Store the sealer vertically. Most slim edge sealers fit upright in a cabinet or on a shelf. These small kitchen cabinet organization ideas and vertical storage ideas can help you find a spot.
• Use it for your dry pantry. In a kitchen with no pantry, sealed rice, nuts and coffee pack flatter than bulky boxes. Here’s how to organize a small kitchen with no pantry.
• Keep containers for daily leftovers. For food you’ll eat in a day or two, airtight food storage containers are faster and reusable. Save the sealer for longer storage.

If you’re deciding whether it’s worth the counter space at all, it features in our list of small kitchen gadgets worth buying when you cook for one.

Your First Batch

Pick one thing you already buy in bulk, like chicken breasts, ground beef or a big block of hard cheese. Portion it, pat it dry, freeze the meat on a tray for an hour, then seal each portion with 3 inches of headroom and a date on the bag. Once that goes smoothly, move on to soups in a loaf pan. By the third batch, the steps above will feel automatic.

Related Guides

• Best Vacuum Sealer for Sous Vide
• Best Sous Vide Precision Cookers
• Best Airtight Food Storage Containers
• How Long Does Chicken Last in the Fridge
• How Long Do Potatoes Last?
• Easy Meal Prep Ideas for One Person in a Small Kitchen
• How to Organize a Small Kitchen with No Pantry

Frequently Asked Questions

How much space should you leave at the top of a vacuum sealer bag?

FoodSaver's owner's manual says to leave 3 inches between the food and the top of the bag so the machine can pull air out and make a clean seal. If you plan to reuse the bag, add at least one more inch for each reuse, since every reseal cuts a strip off the top. Too little headroom is one of the most common reasons a seal fails.

Can you vacuum seal liquids like soup?

Yes, but freeze them first. An edge-style vacuum sealer will pull liquid straight toward the pump and ruin the seal. America's Test Kitchen suggests setting a bag in a loaf pan, pouring in the soup or broth, freezing it until firm, then lifting it out and vacuum sealing the frozen block. Chamber sealers can handle liquids directly.

Is vacuum-sealed food safe at room temperature?

Only dry, shelf-stable foods like crackers, rice, nuts, dried fruit and jerky. Perishable food still needs the fridge or freezer. Removing oxygen can actually help Clostridium botulinum, which grows in moist, low-acid food without air. FoodSaver's manual states that vacuum sealing is not a substitute for refrigeration or freezing, and perishable food should not sit above 40°F for more than 2 hours.

What foods should you not vacuum seal?

FoodSaver's manual says soft cheeses, fresh mushrooms, fresh onions and fresh garlic should never be vacuum sealed, because they can support anaerobic bacteria. Raw vegetables should be blanched before sealing for the freezer. Home-canned food should never be vacuum sealed instead of being properly processed. Moist, low-acid dishes like chili or mushroom soup should be frozen, not kept sealed in the pantry.

How long does vacuum-sealed food last?

FoodSaver claims its bags keep food fresh up to 5 times longer than ordinary storage, mainly by preventing freezer burn. Vacuum sealing doesn't change the food safety clock for refrigerated food much, so follow normal fridge times and treat the extra life as a quality benefit. Food frozen at 0°F stays safe indefinitely; sealing just keeps it tasting better for longer.

Why won't my vacuum sealer seal?

The usual causes are a wet, greasy or wrinkled bag opening, too little space at the top of the bag, a smooth chamber-style bag in an edge sealer, or an overheated machine. Wipe the bag mouth dry, flatten it across the seal bar, and wait about 20 seconds between seals so the heating element can cool, as FoodSaver's manual recommends.