Water Bath Canning Guide: How to Water Bath Can & Times Chart

Looking for a water bath canning times chart? Discover how to water bath can safely, prepare your jars, and adjust processing times for altitude.

How to Water Bath Can: Complete Step-by-Step Guide for Beginners

Home food preservation allows you to stock your pantry with fresh flavors all year. This guide explains the core principles of preserving high-acid foods safely at home using dependable equipment and tested methods.

What is water bath canning?

Water bath canning is a simple, boiling-water food preservation method that submerges glass mason jars in boiling water for a specified processing time to safely preserve high-acid foods. The heat destroys yeasts, molds, and many bacteria and inactivates enzymes that can affect food quality. When the jar cools, a vacuum forms and pulls the lid firmly against the jar rim, creating an airtight seal.

This preservation technique is suitable only for foods with high natural acidity or foods properly acidified according to a tested recipe. A pH level of 4.6 or lower prevents the growth of Clostridium botulinum but does not eliminate the need for proper heat processing. Standard foods preserved by this method include:

• Fruits like berries, peaches, apples, cherries, and pears

• Jams, jellies, fruit spreads, and fruit butters

• Pickled cucumbers, pickled peppers, and other properly acidified vegetables

• Salsas and chutneys prepared with measured quantities of acid according to tested recipes

• Tomatoes properly acidified with bottled lemon juice or citric acid according to tested canning directions

• Relishes, some barbecue sauces, and fruit juices when using tested canning recipes

Low-acid foods like meats, seafood, poultry, plain vegetables, and soups require pressure canning at the time and pressure specified in a tested recipe and adjusted for altitude. Never process low-acid foods using a boiling-water canner.

How water bath canning works

The physical mechanics of hot water bath canning depend on thermal transfer and pressure differentials. When sealed jars enter boiling water, the contents heat up and expand. Air and steam in the headspace are forced from the jar during processing.

During this heating cycle, boiling water provides the heat needed to destroy microorganisms of concern in properly acidified foods and helps inactivate enzymes that can affect food quality. The required processing time ensures that adequate heat reaches the coldest part of the jar.

When processing completes and jars are removed from the canner, the contents contract as they cool. As the jar cools, a vacuum forms and pulls the lid firmly against the jar rim, creating an airtight seal. Allow processed jars to cool undisturbed at room temperature for 12 to 24 hours.

Equipment for water bath canning

Preserving food at home requires appropriate equipment designed for safe canning and handling hot jars:

• Water bath canner: A large metal pot with a fitted lid and rack, deep enough to keep the jars covered with at least 1 inch of boiling water throughout processing. For processing times longer than 30 minutes, keep 2 inches of water above the jars.

• Canning rack: A wire or silicone insert that keeps jars off the bottom of the canner while allowing boiling water to circulate around them.

• Mason jars: Tempered glass containers designed for home canning and available in various sizes. Use only the jar sizes specified in the tested recipe.

• Lids and rings: 2-piece closure systems featuring flat metal sealing discs and threaded bands for reliable vacuum seals.

• Jar lifter: A specialized clamp with rubber tongs to lift hot, wet glass jars vertically without tilting.

• Bubble popper and headspace tool: A stepped spatula used to measure headspace depth and release trapped air pockets.

• Wide mouth canning funnel: A heat-resistant funnel that channels contents cleanly into jars without dirtying rims.

• Accessories: Clean kitchen towels and a timer. Prepare lids according to the lid manufacturer's instructions.

If you do not own a specialized boiling water canner, any deep stockpot equipped with a fitted lid and a bottom rack will work as long as it is deep enough to keep the jars covered by the required amount of boiling water throughout processing.

How to water bath can

Follow these tested steps to learn how to water bath can with precision and ensure safe food storage:

Step 1: Select produce and follow tested recipes

Always begin with fresh, unblemished fruits and vegetables. Wash produce under clean running water. Follow laboratory-tested instructions from trusted sources such as the National Center for Home Food Preservation or university extension services. Never alter the proportions of ingredients such as vinegar, water, produce, or other ingredients that affect the acidity of a tested pickling recipe.

Step 2: Inspect and prepare glass jars and lids

Check glass jars for nicks, cracks, or uneven rims. Discard damaged glass because it can break during processing or prevent a proper seal. Wash jars, bands, and lids according to the manufacturer's directions. Keep clean jars hot in water until they are filled. Do not heat canning jars in an oven.

Step 3: Heat the preserving vessel

Learn how to use a water bath canner efficiently by filling the canner about halfway with clean water. Place the pot on your stovetop burner and preheat the water to 140°F for raw-packed foods or 180°F for hot-packed foods. Adjust the amount of water as needed so the filled jars will be covered by the required amount of water during processing.

Step 4: Pack food into jars and adjust headspace

Fill warm jars with prepared food using your canning funnel. Leave the exact headspace designated by your recipe:

• ¼" headspace for many jams and jellies

• ½" headspace for many fruits, pickles, and tomatoes processed in a boiling-water canner

• Use the exact headspace specified in your tested recipe for all other products.

Headspace provides the necessary expansion chamber for food during thermal processing and helps a vacuum form as the jar cools.

Step 5: Remove air bubbles and clean rims

Insert your plastic bubble popper along the interior walls of each jar, when directed by the recipe, pressing gently inward to release trapped air bubbles. Recheck headspace and add liquid if levels dropped. Wipe the top rim of each jar as directed by the tested recipe, typically with a clean, damp paper towel, to remove food or other residue that could interfere with sealing.

Step 6: Apply lids and screw bands

Center a flat metal lid on the clean glass rim. Apply the screw band according to the lid manufacturer's directions, generally tightening it fingertip-tight. Do not overtighten the band, because air needs to escape from the jar during processing.

Step 7: Load jars and process in boiling water

Use your jar lifter to load jars vertically into the canning water bath rack. Keep jars upright without tilting. Ensure water covers jar tops by at least 1". For processing times longer than 30 minutes, keep at least 2" of water above the jars. Place the lid on the canner and increase heat to high. Start your timer only when the water reaches a vigorous rolling boil. Maintain a complete boil for the entire processing time specified by your tested recipe. If the water stops boiling at any point, return it to a vigorous boil and restart the processing time from the beginning.

Step 8: Cool jars and test seals

When the processing timer sounds, turn off the heat, remove the canner lid, and wait 5 minutes before removing the jars. Use the jar lifter to transfer jars onto a dry towel or cooling rack, leaving at least 1" of space between jars. Allow jars to cool at room temperature for 12 to 24 hours. Do not touch, press down on, or tighten screw bands while jars cool.

After 12 to 24 hours, test the seals:

1. Press the center of the lid; if it springs up when you release your finger, the jar is not sealed. A properly sealed lid should be slightly concave.

2. Remove the metal screw band before checking and storing the sealed jar. Do not lift the jar by the lid as a routine seal test.

3. Wash and dry sealed jars as needed, label them with the product name and processing date, and store them without screw bands in a cool, dark, dry pantry.

Water bath canning times chart

Processing times vary depending on the specific food and recipe, jar size, pack style, and elevation above sea level. Water boils at lower temperatures at higher elevations, requiring longer processing times. Consult this water bath canning times chart for general reference.

Important: Processing times vary by the specific food, tested recipe, jar size, pack style, and altitude. This chart is a general reference only. Always follow a current, research-tested canning recipe for the exact processing time and preparation method.

Safety guidelines & troubleshooting

Strict adherence to safety standards makes boiling water bath canning dependable:

• Acidity control: For tomatoes, follow the acidification directions in the tested recipe. NCHFP's crushed-tomato recipe requires bottled lemon juice or citric acid to be added to the jars before processing.

• Siphoning: Liquid loss during processing can occur for several reasons. Follow the tested recipe's headspace instructions, keep jars upright, maintain the required processing conditions, and allow the recommended 5-minute wait after turning off the heat before removing jars.

• Unsealed jars: If a jar fails to seal within 24 hours, refrigerate and use the food promptly, freeze it in a suitable freezer container, or reprocess it within 24 hours according to tested instructions.

• Signs of spoilage: Do not taste food from a jar that shows signs of spoilage, such as an unsealed or bulging lid, spurting liquid, unusual odors, mold, or other abnormal appearance. Follow USDA/NCHFP guidance for safely discarding suspect food.

• Elevation check: Always verify your local elevation. Boiling-water processing times must be adjusted when you are more than 1,000 feet above sea level according to the tested recipe.

Frequently Asked Questions

What is water bath canning?

It is a food preservation method that processes properly prepared foods in glass canning jars in boiling water for a tested amount of time. It is used for high-acid and properly acidified foods with a pH of 4.6 or below.

What foods are unsafe for water bath processing?

Meats, poultry, seafood, most dairy products, dried beans, carrots, potatoes, plain vegetables, soups, and corn are low-acid foods and should not be processed in a boiling-water canner. Tested recipes for these foods generally require pressure canning because boiling-water temperatures are not high enough to destroy Clostridium botulinum spores.

How to do a water bath for canning?

Fill a deep pot with water, preheat it, lower filled jars onto a bottom rack, and make sure the water covers the jar tops by at least 1 inch. For processing times longer than 30 minutes, use at least 2 inches of water above the jars. Bring the water to a vigorous boil and process for the full time specified in the tested recipe, adjusting for altitude when required.

Can you reuse metal canning lids?

Do not reuse flat metal lids for home canning unless the lid manufacturer specifically identifies them as reusable. Standard single-use metal canning lids should be replaced after each canning cycle. Screw bands can be reused if they are clean and in good condition. Always follow the lid manufacturer's instructions.

Can jars touch in water bath canner?

Jars should be positioned so boiling water can circulate freely around each jar. Avoid crowding or wedging jars tightly together in the canner, and use an appropriate canning rack.