Water Bath Canning for Beginners: Safe Step-by-Step Guide

By the Garden Voila editorial team · Updated October 27, 2026 · How we verify

Water bath canning (boiling water canning) is the safe home method for high-acid foods only: fruits, jams and jellies, fruit juices, properly acidified tomatoes, pickles, relishes, salsas and chutneys made from tested recipes. Fill clean canning jars with hot food, leave the headspace the recipe specifies, wipe the rims, apply new two-piece lids finger-tight, and process the jars fully submerged under at least 1 inch of boiling water for the exact time in a tested recipe, adding time at higher altitudes. Let jars cool undisturbed for 12 to 24 hours, check that every lid has sealed, then store them in a cool, dark place and use within a year. Low-acid foods such as plain vegetables, beans, meat and soups must be pressure canned instead, because boiling water cannot destroy the spores that cause botulism.

Water bath canning at a glance

Why do high-acid foods matter?

The bacterium Clostridium botulinum, which causes botulism, forms heat-resistant spores that are common in soil and on produce. In a sealed jar with little oxygen and low acidity, those spores can germinate and produce a deadly toxin without any visible signs of spoilage. Acid prevents this: foods with a pH of 4.6 or lower do not support botulinum growth, so the temperature of boiling water (212°F at sea level) is enough to destroy the molds, yeasts and other bacteria that spoil high-acid foods. Low-acid foods need the higher temperature, 240°F, that only a pressure canner reaches. This is why the USDA Complete Guide to Home Canning, published through the National Center for Home Food Preservation, is the foundation of every safe home-canning recipe: processing times are tested for each food, jar size and preparation method.

What equipment do you need?

• Water bath canner or large stockpot with a lid, deep enough to cover jars with at least 1 inch of water plus room to boil, and a rack to keep jars off the bottom.
• Mason-type canning jars made for home canning, in good condition with no chips or cracks. Do not reuse commercial mayonnaise or pasta sauce jars.
• Two-piece lids: new flat lids with sealing compound, plus screw bands.
• Jar lifter to move hot jars safely.
• Canning funnel, headspace tool or ruler, and a plastic bubble remover or spatula.
• Clean towels, a timer and a tested recipe.

How do you water bath can, step by step?

1. Choose a tested recipe from a reliable source and gather ingredients and equipment. Read the whole recipe first.
2. Inspect and wash jars, lids and bands in hot, soapy water and rinse. Keep jars hot (in the canner water, a dishwasher on heated dry, or a pot of hot water) so they do not crack when filled with hot food. Jars processed for 10 minutes or more at sea level do not need to be sterilized first; for shorter processing times, boil empty jars for 10 minutes.
3. Heat the canner: fill it about half full of water and heat to about 180°F for hot-packed food, or 140°F for raw-packed food.
4. Prepare the food exactly as the recipe says, including any added acid, sugar or salt.
5. Fill the jars using a funnel, leaving the specified headspace (the space between the food and the jar rim).
6. Remove air bubbles by sliding a plastic bubble tool down the inside of the jar, then readjust headspace if needed.
7. Wipe the rims with a clean, damp cloth so no food prevents the seal.
8. Apply lids and bands, tightening bands only fingertip-tight so air can escape during processing.
9. Load the canner with a jar lifter, keeping jars upright and not touching. Add hot water if needed to cover the jars by at least 1 inch.
10. Bring to a full rolling boil, then start the timer. Cover the canner and keep the water boiling throughout. If boiling stops, bring it back to a boil and restart the full time.
11. Turn off the heat when time is up, remove the lid and wait 5 minutes. This helps prevent siphoning (liquid loss).
12. Remove the jars with the lifter, keeping them upright, and set them on a towel in a draft-free spot, 1 to 2 inches apart. Do not tighten bands or press lids.
13. Cool for 12 to 24 hours. You may hear lids “ping” as they seal.

How do you adjust for altitude?

Water boils at lower temperatures as altitude increases, so processing time must increase to destroy microorganisms. Most USDA water bath recipes use the following adjustment, but always check the recipe, since some list different times.

If you are unsure of your altitude, contact your local extension office or look up your elevation online.

How do you check that jars sealed?

After 12 to 24 hours, remove the bands and test each lid:

• Press the center of the lid. A sealed lid is concave and does not flex or pop back.
• Lift the jar gently by the lid edges (over a towel). A sealed lid holds firmly.
• Look at the lid: it should be curved down slightly in the center.

If a jar did not seal, refrigerate it and use the food within a few days, or reprocess within 24 hours using a new lid and the full processing time (quality will decline). Wash the outside of sealed jars, label them with the contents and date, and store them without bands, which can hide a broken seal and rust in place.

How should you store home-canned food?

Store jars in a cool, dark, dry place, ideally between 50°F and 70°F. Avoid hot attics, spots near furnaces or stoves, damp basements and direct sunlight, which degrade quality and can cause seal failure. Home-canned foods are best eaten within a year; after that they remain safe if properly processed and sealed, but color, flavor and nutrition decline. Before opening, check every jar for signs of spoilage: bulging or unsealed lids, leaking, spurting liquid, mold, off odors, cloudy liquid (in foods that should be clear) or unnatural color. When in doubt, throw it out without tasting.

Which foods can you water bath can?

For plain vegetables, beans, meat and soups, see pressure canning vegetables. The Michigan State University Extension basics of water bath canning also explains the difference between acid and low-acid foods.

What are the most common water bath canning mistakes?

• Using untested recipes from blogs, social media or old family cookbooks, or changing ingredient amounts in tested recipes.
• Water bath canning low-acid foods such as green beans, corn, carrots or soups.
• Skipping added acid in tomatoes, even for “high-acid” varieties.
• Oven canning, open-kettle canning or inversion (flipping hot jars upside down instead of processing); none of these are safe.
• Starting the timer before the water boils, or letting the boil drop during processing.
• Not adjusting time for altitude.
• Overtightening bands, which can cause lids to buckle or fail to seal.
• Reusing flat lids, which seal unreliably the second time.
• Using a dishwasher, microwave or slow cooker to “process” jars.
• Thickening with flour or cornstarch before canning, which slows heat penetration. Add thickeners when serving.

Can you use a regular stockpot?

Yes, any large pot works as a water bath canner if it is deep enough for jars to be covered by at least 1 inch of water with 1 to 2 inches of extra space for boiling, has a tight lid, and has a rack or a folded towel on the bottom to keep jars off direct heat. For pint jars, a tall pasta pot often works; quarts need a deeper pot. On glass-top stoves, check the manufacturer’s guidance, since large canners can exceed the burner size and weight limit.

Is it safe to can with less sugar or salt?

In canned fruits, sugar helps preserve color and texture but is not needed for safety, so fruit can be canned in water or juice. In jams and jellies, sugar affects gelling and preservation; to reduce it, use pectin made for low- or no-sugar recipes and a recipe written for that pectin. In pickles, salt can be reduced only in quick-process (fresh-pack) pickles, never in fermented pickles, and never reduce the vinegar. Spices and herbs can be adjusted in most recipes, but low-acid ingredients such as onions, peppers and garlic should not be increased in salsas and relishes.

Getting started: a first canning project

If you are new to canning, start with a simple, forgiving recipe: strawberry or mixed berry jam, applesauce, or refrigerator-friendly pickles you then process. These teach the basic steps without long processing times. Grow your own produce for canning with our guides to growing tomatoes, cucumbers and strawberries, and for fruit that does not need canning, see how to store apples and how to make prunes. The North Dakota State University Extension guide to water bath canning is a handy printable reference.

For every canning, freezing, drying and storage guide in one place, visit our food preserving hub.

Water bath canning FAQ

References used in this guide: National Center for Home Food Preservation, USDA Complete Guide to Home Canning (2015 revision); Michigan State University Extension, Basics of Water Bath Canning; North Dakota State University Extension, Water Bath Canning.