Water Bath Canning | A Beginners Guide

This simple but in-depth guide will help you learn how to water bath can with confidence. I’ve canned thousands and thousands of jars of food and I’ve read extensively on the how and why behind canning. Even though I’ve become an expert, I still follow canning safety rules vigilantly because it’s important. Once you’ve masted the basics of water bath canning, it will open a new world of homemade delicious food.

What is Water Bath canning?

Water bath canning is a food preservation method. It’s use is ONLY for high acid foods or foods made to be acidic with the addition of lemon juice, vinegar, or citric acid.

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How it Works

A packed jar of food is fitted with a two piece lid and screw-ring. Next, it is placed in a water bath canner filled with hot water. A water bath canner consists of a large, deep pot with a metal rack on the bottom to hold jars and a lid.

The water is brought to a boil and held there for a set amount of time. The heat kills harmful bacteria, yeasts, and enzymes which can spoil food. Additionally, heat expands the food, pushes out the air, and it creates and oxygen free environment.

This method creates a vacuum seal inside the jars and tightly seals the lids.

Water bath Canning vs. Pressure Canning

It’s important to note that there are two types of canning, boiling water bath and steam pressure canning.

Water bath canning is for high acid foods with a cumulative pH lower than 4.6. The food processes at the boiling point, or 212ºF.

Pressure canning is for low acid foods with a cumulative pH of 4.6 or higher. Low acid food must be processed at a temperature of 240ºF to destroy all bacteria, spores, and toxins. A pressure canner reaches and maintains a 240ºF temperature for the entire processing time. This allows low acid food to be safely canned.

Pressure canning is required in low acid canned foods because of a risk for a bacteria known as bacterium clostridium botulinum. It can cause a serious food poisoning known as botulism. 

Botulism-causing bacteria thrives on low acids in the absence of air in moist environments- exactly the conditions inside a jar of canned vegetables, meats and other low-acid foods.

Source: The Ball Guide to Preserving

Botulism and it’s spores are destroyed at 240ºF. This temperature is only achieved with a pressure canner. Even though the threat of botulism sounds scary, don’t let it hold you back. I only mention it so that you are aware that canning is not a place to adjust ingredients. If a tested canning recipe is followed exactly, there is no need to fear. The food is safe to consume.

Which Method of Canning Should You Use?

To put this simply, follow a recipe tested for safety and it will direct you with the proper method of canning.

Examples of High Acid Foods for Water Bath Canning:

• Apples
• Cranberries
• Blueberries
• Lemons
• Plums
• Blackberries
• Sour cherries
• Yellow peaches
• Pears
• Grapes
• Pickles
• Fruit Jams and Jellies
• Tomatoes (Some tomato varieties are very close to 4.6 pH. Therefore, many tomato recipes have added lemon juice, vinegar, or citric acid to ensure a safe product).

Examples of Low Acid Foods for Pressure Canning ONLY:

• Soups
• Meats
• Green beans (when canned plain with only salt and water)
• Potatoes
• Dried Beans
• Corn

Equipment

The basic canning equipment for water bath canning is:

1. Large Pot or Saucepan
2. Rack for inside stockpot (usually this is included in the purchase of water bath canner)
3. Mason Jars
4. Headspace Measuring Tool
5. Canning Rings
6. Ladle
7. Chopsticks or Wooden Skewers
8. Jar Lifters
9. Funnel
10. Jar Lids

I recommend getting equipment made especially for canning. If you plan on canning more than a couple times, it’s worth the cost. For more details, check out my blog post about canning equipment, it details why each item is necessary, and links to what I use and recommend.

How to Fill Canning Jars, Raw Pack vs. Hot Pack 

There are two methods for packing jars with food- raw pack and hot pack. Almost all canning recipes designate the proper method to use. Sometimes either method is satisfactory.

Hot pack means food is precooked in a brine, syrup, juice, or water before being placed in the jars. Additionally, hot packing is the preferred method for almost all fruits and vegetables. 

Raw pack means food is packed into the jar raw. Boiling brine, syrup, juice, or water is added over top. This method is advantageous for food that is delicate after cooking. For example, I always raw-pack my pickles when canning. Sliced cucumbers are added to the jar raw, then a very hot vinegar brine is added over top.

Step by Step Instructions for Canning with a Water Bath Canner

1. PREPARE JARS

First, check for any chips on the rims of the jars or hairline cracks in the jars. Remove any that have problems. Next, heat the jars. This is done in two ways, depending on the recipe.

• For a water bath canning recipe that boils for less than 10 minutes, the jars need to be sterilized first (source). To sterilize the jars, fill the canning pot fitted with a rack with mason jars and warm water. Water should be at a level one inch above the jars. Boil for 10 minutes at elevations less than 1000 ft. Yes,  you need to know how many feet you are above sea level. If you aren’t sure what that is, you can find it out HERE. Boil 1 additional minute for each additional 1,000 ft. elevation increase.

• If the canning recipe requires boiling for more than 10 minutes, the jars do not need to be sterile but they must be hot. This can be done by filling the canning pot fitted with a rack with warm water and jars, then heating them up over a stove top. Other options include running a short hot water cycle in the dishwasher with only canning jars and no soap. Keep the dishwasher closed until the jars are ready to use. Dry heating in an oven is not recommended.

2.  PREPARE LIDS AND RINGS

Most canning lids have instructions on the back of the box specific to that brand. For Ball and Kerr brand lids or similar, wash in warm to hot water. I usually do about 100ºF or when the water feels hot to the touch. I rinse them under the faucet at the sink. Also, rinse rings in hot water as well. Set aside.

NOTE: Canning lids DO NOT need to heat to 180ºF. This is an old method that has proved to be unnecessary. The hot water rinse is sufficient. **And adding my personal experience here, 15 years ago when I first started, I heated the lids as recommended. It added time and I had way more seal failures than I do now. I’m so glad that we now have an easier method that works better!

3. MAKE RECIPE

As the jars are heating, make the canning recipe. How the food is prepared varies widely based on what recipe you are following. Some recipes say you can raw pack or hot pack (info on that is above if you missed it) but most have step by step instructions. As mentioned above, following the recipe exactly is important for a safe end result. 

4.  PACK JARS WITH FOOD

When the food is ready to be packed in jars, take the hot and empty mason jars and set them on a firm surface with a cloth or clean rag underneath. Fill the jars with the food. Sometimes the recipe is already all together like a salsa or a jam, sometimes food is placed in the jar and hot brine is added. 

Either way the most important thing when filling the jar is to place hot food and/or hot liquid in a hot jar. It should be neither boiling nor cold (with the exception of food that is raw packed, but even then the liquid should be hot.)

One reason to have the similar jar and food temperature is the jars can crack from the temperature difference. Another reason is if too cold it will take longer to process jars and destroy microorganisms. As such, the tested processing time would be incorrect.

5. REMOVE AIR BUBBLES

Take a clean wooden skewer or slim wooden utensil and slide it down the side of the jar in a few places. This process removes any air bubbles that have formed.

6. MEASURE HEADSPACE

Headspace is the space in the jar between the top of the food or liquid and the top of the jar. A tool for measuring this space comes with most canning kits or you can even use a regular ruler. To create a proper vacuum seal, a recipe will state the needed amount of headspace.

The Ball Blue Book guide to preserving states: 

As a general rule, leave 1-inch headspace for low-acid foods, vegetables and meats; ½-inch headspace for high acid foods, fruits and tomatoes; ¼-inch headspace for juices, jams, jellies, pickles and relishes.

Also a quick FYI if you skipped straight to the steps- low-acid foods require a different method of canning, called steam pressure canning.

7. WIPE RIMS, ADD LIDS AND RINGS

Next, wipe the rims of the jars with a clean, damp cloth. I usually dip a cloth in the very hot water I used from heating the jars. The reason for wiping the rims is to remove any food residue. This will help the lids to seal well. 

Add a lid to each jar, then secure with a metal ring. Lids will need to be as centered as possible so the sealing compound is touching the glass on the rim. Then screw the ring overtop to keep it in place. 

Rings should be “finger-tip tight” meaning that you tighten the rings with ONLY your finger tips. This keeps the ring from going on too tight. However, it should be firm and snug, even when done with finger tips.

8. PROCESSING

Fill a boiling water bath canner about half full with water and heat it up. The best water temperature is the one that nearly matches your jars and the food packed in them. In general, if you bring the water to a simmer then take it off heat as you fill the jars it’s just the right temperature. 

If you used the boiling water bath canner for heating your jars, you can reuse that hot water already in the canner. 

Load the jars into the prepared canning pot, fitted with a rack. The level of the water should be at least one inch above the top of the jars.

Put the water bath canner lid in place. Turn heat on and bring water to a boil. Once at a rolling boil, start the timer for the processing time. Increase processing time for altitudes 1000 ft above sea level. See chart below.

Water Bath Canning Altitude Adjustment Chart

After the processing time is finished, turn off the heat and remove the canner lid. Let everything cool and sit for 5 minutes before removing the jars.

Remove jars from the canner pulling up straight and setting them upright on a firm surface with a towel or clean cloth underneath. Do not tip the jars as you pull them out to get the water off the lid. Another thing to avoid is touching part of the canning jars. For example, don’t try and push in the seal. It will make a “pop” sound on its own if the jar seals properly. Also, don’t tighten the ring. Basically don’t touch it!

Let jars cool naturally on the counter for 12-24 hours. After that time check the seal by seeing if the middle of the lid is concave. Press the center and make sure the lid doesn’t flex at all. An additional way to test the seal is to try and lift the lid off with your fingertips. The jar seals when it holds firm and the center doesn’t flex.

9. STORAGE

The final step is to remove the ring and take a clean rag and wipe off any residue underneath and on the jar. Keep the rings off for storage. The reason for not having a ring on the jar is it makes it easier to spot a jar that loses a seal. And it also keeps away mold that might form on food or liquid trapped under a canning ring.

Store at room temperature, 50-70ºF ideally. Properly canned food can store for 1-2 years. After a year, the food quality begins to go down. I’ve personally had canned food for three or four years but I wouldn’t eat canned food past four years old. Likely, the nutrient density, consistency, and quality is so low it’s not worth eating.

Light destroys vitamins so store in a place that is absent of light, like a cabinet or room that doesn’t receive direct sunlight.

FAQ

What does “processing” mean in regards to canning? Processing means to apply heat to food contained in canning jars at the correct temperature, and hold at that temperature for a time specified on a tested recipe. 

Are vacuum seal lids reusable? No, most vacuum seal lids aren’t reusable and are one time use. However, there is a certain type of lid that is reusable and that is Tattler brand lids. The method of using these lids is quite different from single use lids. Make sure you read instructions carefully for success. 

Is a recipe necessary for water bath canning? If you are a beginner, I highly recommend using a recipe. Canning is not a place to adjust ingredients and be creative. This is due to the possibility of the adjustments affecting the acid level of the food. 

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