What is the difference between a vacuum sealer and a water bath canning?

A vacuum sealer removes air from a bag around food and heat seals the bag closed, which is a cold storage method for the refrigerator or freezer. Water bath canning packs food into jars and processes them in boiling water so the jars seal and the contents keep on a shelf. The two do different jobs and are not substitutes for each other.

The difference comes down to what happens to the food afterward. A sealed vacuum bag still needs cold storage and still has a limited life. A properly processed canning jar is sealed by heat and vacuum created inside the jar during cooling, which is why water bath canning is limited to high acid foods like fruit, pickles, jams and tomatoes. Our Best Vacuum Sealers for Dry and Moist Food and Best Water Bath Canners for High Acid Preserving guides cover the equipment on each side.

How each method works

A vacuum sealer draws air out of a textured or embossed bag and then fuses the bag with a heated strip. The Gasbye VS5166 uses a double heat seal, which the maker describes as dual sealing strips that create tight, consistent seals for dry and moist foods. The Nesco VS-12 uses a 130 watt double vacuum pump and double heat seal technology. Air removal and a closed seam are the whole mechanism.

Water bath canning works by heat. Jars are filled, lidded, set on a rack and lowered into boiling water, and the rack keeps them off the bottom so water circulates. The McSunley Prep N Cook canner holds 7 one quart, 9 one pint or 12 half pint jars on its rack. When the jars cool, the lid pulls down and seals.

The vacuum sealer produces a bag with no air in it. The canner produces a jar with a vacuum inside it, created by the processing and cooling step. One is a storage bag, the other is a sealed container that does not need refrigeration once the seal takes.

What each machine looks like on the counter

Vacuum sealers are countertop appliances with a slot for the bag. The FoodSaver compact model measures 5.59 inches wide, 17.91 inches deep and 10.24 inches high and weighs 4.5 pounds, and the maker states it stores vertical to save countertop space. The Beelicious Pro VSP801 measures 8.9 inches wide, 15.7 inches deep and 4.8 inches high and weighs 5.87 pounds. The Gasbye VS5166 measures 7.8 inches wide, 15.7 inches deep and 4.7 inches high and weighs 6.5 pounds.

Water bath canners are large pots. The McSunley measures 14.2 inches wide, 14.2 inches deep and 11.2 inches high and weighs 11.11 pounds, with a 21.5 quart capacity. The Kitchen Crop Harvest is a 20 quart pot measuring 17.5 inches wide, 13.1 inches deep and 11.5 inches high and weighing 10.1 pounds. The Kendane pot measures 15 inches by 15 inches by 9.8 inches and weighs 10.8 pounds.

One sits on the counter and takes a bag. The other sits on a burner and takes water and jars. The canner is the larger and heavier object in every case where both figures are published.

What foods each method is for

A vacuum sealer handles raw and cooked food in bags: meat, fish, produce, leftovers, dry goods. The Chef Preserve handheld unit lists meat, fish, vegetables, fruits, dry goods, pizza, cooked food and leftovers. The Beelicious Pro has an extra moist mode for marinated meats, fish and seafood, and the Nesco VS-12 lists dry, moist and double seal modes with a gentle vacuum option for soft foods like bread and berries.

Water bath canning is for high acid foods only. The Kendane listing names preserves, jams, jellies, pickles and salsa, and the CLMSTE listing names fruits, pickles and condiments. The Kitchen Crop canner can be used for traditional water bath canning or flipped for steam canning. Low acid vegetables, meats and soups are not water bath canning projects.

This is the practical dividing line. If the food needs refrigeration anyway, a vacuum bag is the simpler container. If the goal is a jar on a pantry shelf, the food has to be acidic enough for a boiling water process.

Cooktop and power requirements

Vacuum sealers plug into an outlet. The Nesco VS-12 is rated at 130 watts. The Chef Preserve handheld runs on a rechargeable battery and the maker states one charge seals 1000 bags. None of the other sealers on the fact sheet publish a wattage, so this site has not compared their power draw.

Canners depend on the stove. The McSunley has a flat encapsulated base designed for all cooktops including induction and glass top ranges. The Kitchen Crop pot is induction compatible and safe for smooth top ranges. The Kendane pot is explicitly not suitable for induction and glass cooktop hubs, and the CLMSTE pot is not recommended for glass cooktops. Check the burner before the pot.

Seals and what they hold

The sealer seal is a heat weld across plastic. The Gasbye maker states the double seal helps reduce leaks during long water bath cooks for sous vide, which is a different water bath from canning: a temperature controlled cooking bath, not a boiling process for jars. The FoodSaver maker states the unit keeps food fresh in the freezer up to 5 times longer and seals with 35 percent less bag waste than previous models.

The canner seal is a lid on a jar. The Kitchen Crop lid has a built in temperature indicator in the knob, and the maker says to start timing when the needle reaches the appropriate mark. The McSunley lid is tempered glass and shatter resistant. Neither maker publishes a seal life figure, and this site has not compared one.

Both methods remove air, and that is where the similarity ends. One stores food cold in plastic, the other stores food at room temperature in glass.