Water bath canning allows you to preserve delicious produce (like tomatoes, berries, and apples) when they’re at peak ripeness.
Best of all, you can munch on them directly from the jar. No refrigeration (or connection to the grid) is required.
This article covers water bath canning for beginners, so anyone can get started.
And prepare to get addicted! Once you start canning, it’s very hard to stop.
What is Water Bath Canning?
Water bath canning is a form of food preservation that uses hot water to both kill bacteria and hermetically seal food inside a jar.
Let’s break this down a bit.
All of the foods we grow or purchase are coated with bacteria and harmful spores. Water bath canning involves heat. As temperatures rise, bacteria on the jars and inside the food die.
Lids placed on jars right before canning are activated by heat and form a tight seal. That seal keeps air from contacting the food inside the jar. Airborne germ and mold spores can’t touch the contents, so the food stays safe to eat.
At the end of a successful water bath canning process, you’re left with shelf-stable food that’s safe (and tasty) to eat.
Benefits of Water Bath Canning
Getting started with water bath canning is easy. You don’t need thousands of dollars in equipment to get started, and you can do the work from the comfort of your kitchen.
Of all the potential water bath canning benefits, this might be the most appealing.
Canning can also save you money. When your garden is bursting with produce, you’ll spend next to nothing on raw materials.
When winter comes, and your neighbors are facing big grocery bills on foods grown, who knows where, you’ll be eating healthy, inexpensive food you prepared yourself.
The foods you’ll preserve are free from things like food coloring, artificial preservatives, and added salt. Since you’re supervising the process, you know exactly what’s inside each can.
I also find water bath canning deeply nostalgic. People have used this method to preserve food for hundreds and hundreds of years. It’s wonderful to use this method to return to our roots.
Understanding Acidity in Canning
All foods can harbor mold, yeast, and bacteria. However, the acidity of the food plays a role in how persistent those contaminants can be.
High Acid vs. Low Acid
High-acid foods (like lemons and pickles) come with their own inherent protection. Invaders are easier to kill with heat in a high-acid environment. That’s why high-acid foods can be safely preserved with a water bath.
Low-acid foods (like carrots, beans, and corn) need more heat to be truly safe inside a can, even if it’s sealed properly. That’s why foods like this either need a little help to become acidic for a water canner—or they should be preserved in a pressure canner instead.
A pressure canner can heat food inside your jars to temperatures you just can’t reach with a water canner. For low-acid foods, it’s really the only safe method.
Recipes Will Keep You Safe
You don’t need a degree in food safety or home economics to preserve food safely. You do, however, need a recipe.
Every recipe you use for canning (and you should always use a recipe) will tell you which type of canner to use and how to prepare your food. Never use a water canner when your recipe calls for a pressure canner.
What You Can and Can’t Water Bath Can
Curious about what you can (and cannot) preserve with a water canner?
Of course you are. Here’s what you need to know.
Foods Suitable for Water Bath Canning
The South Dakota State University Extension explains that food with a pH of 4.6 or higher is considered a high-acid food. This is the type of product you can preserve in a water-based canner.
Foods with naturally high acid levels include:
- Berries
- Peaches
- Plums
- Lemons
- Oranges
- Cherries
Foods that are acidified before water canning include:
- Pickled vegetables (acidified with vinegar)
- Tomatoes (acidified with lemon juice)
Foods Unsuitable for Water Bath Canning
While some foods (like tomatoes) can be altered for water canning, others cannot. Sometimes, it’s just not possible to tinker with them enough to get them to a safe level of acidity.
In other cases, acidifying them would make them inedible (Pickled deer meat, anyone?).
Foods that just aren’t suitable for water canning include:
- Unpickled or acidified vegetables
- Red meat or poultry
- Seafood
- Dairy products
Some of these foods can be safely preserved with a pressure canner. For example, the Ohio State University Extension says red meat can be processed in a pressure canner at 10 to 15 pounds of pressure per square inch for 20 to 90 minutes (depending on the type of meat).
I know several families that pressure can like pros and put up all sorts of bean and meat-based soups and stews. I stick to the trusty water bath for my canning—which means I use a freezer or dehydrator for everything else.
Risks of Improper Canning
Why should you follow a recipe and pay attention to acidity? Some of the nastiness packed inside your jars could make you really sick.
For example, a water bath can kill the bacteria Clostridium botulinum. However, as the USDA explains, spores can remain.
If your jars aren’t sealed properly, those spores can activate and produce toxins. Without proper (and quick) treatment, contaminated food can cause death.
Poisoning is serious, and it’s smart to be cautious. Always follow a recipe carefully (no detours!), and be alert and aware as you work. But know the danger is there.
Signs a can has gone bad include:
- Leaking
- Bulging lids
- Cloudy liquid that should be clear
- Nasty smells
If you spot something suspicious, don’t do a taste test (obviously). Place the damaged jars in trash bags and throw them out.
Essential Equipment
Now that we have all of the warnings out of the way, let’s get canning! As I mentioned, it’s really easy to get started.
Basic Tools
If you’ve ever shopped for a complete canning starter kit, you know how complicated this can be. Every kit seems to include a different set of tools!
I am a regular canner, and these are the only specialized tools I use with every batch I make:
- Canner(s). I have two sizes of canner. One is made for jam jars (so it’s not very deep), and the other is designed for quart jars (so it’s bigger). If you’re only canning one size of jar, you’ll only need one. If budgets are tight, get the largest one you find. Ensure that it comes with both a lid (to trap in the heat) and a rack (to lift jars up and down while keeping them from touching the bottom of the pan).
- Jars. Unfortunately, you can’t use the jars you have lying around your home. You’ll need special products that are designed to heat and cool over and over again without breaking.
- Lids. Canning lids are metal with a small ring around the edge. That ring forms a tight seal with your glass. You can only use these once, and they’re often hard to find during peak canning season. I buy in bulk when I see them.
- Rings. A ring connects the lid and jar during the canning process. These flimsy metal bits can be reused (as long as they’re not rusty).
- Jar lifter. Jars are both slippery and super hot. A jar lifter is a specialized tool that will allow you to handle your precious products without burning your fingers.
- Funnel. Bits of food and syrup on the edges of your jar will block a tight seal. And nothing is worse than splattering your product all over your counter instead of inside your jar! A funnel makes loading up your jars safe and effective.
- Lid lifter. Your lids will simmer in a water bath while you prepare your jars. Since lids are metal, they get really hot. A lid lifter allows you to pull them out quickly and easily.
Some of my canning colleagues have fancy (but optional) equipment that you might decide is just right for you. Those tools include:
- Bubble removers. Trapped air inside your jars can allow bacteria to grow. A bubble remover tool helps you shift food to the center before canning to remove the air. (I use a simple butter knife instead.)
- Headspace measuring device. All jars need a little space at the top to allow food to expand during processing. Some people buy special measuring tools for this purpose. (I use a ruler.)
Things you probably already have in your kitchen and will need for canning include the following:
- Stainless steel pan. Many recipes call for stainless steel, as it won’t react with the items you’re cooking. Get the biggest one you can find if you’re preparing big batches of food.
- Saucepan. You’ll need a small pan to heat your lids in water. Preferably, this pan won’t have a nonstick coating, as the lids will scratch that to pieces.
- Ladle. You’ll need something to pull food out of the pan and into the jars.
- Timer. Canning involves watching the clock, both for recipe cooking and canning times.
Preparing for Canning
Like most home canners, I’ve experienced a few heartbreaking episodes of failure. In most cases, those problems could have been prevented if I had taken a little more care with my tools before I jumped right into canning.
Don’t be like me! Take these steps.
Examine the Food
If you start with poor produce, you’ll end with a poor canned product. While many parts of canning are truly miraculous, no recipe can take food from bad to good.
Produce that is ready for canning is:
- Ripe enough to be edible but not so ripe that it’s falling apart
- Firm and not bruised
- Free of mold and insects
- Washed and rinsed
Sort all of your produce by hand and set aside anything that isn’t quite right. You can eat these things immediately or freeze them.
Examine the Jars
Your canning jars can be used over and over again. (Hooray for kitchen recycling!) However, you must check them carefully before you push them into service.
Tiny chips at the top of your jars can block a tight seal. If you’ve stacked your jars in towering piles, they’re probably chipped. I run my finger across the top of every jar before I use it. If I get cut, out goes the jar.
Next, hold them up to bright light and look for cracks or notches in the sides or bottom of the glass. Damaged jars will explode (sometimes taking your food with them), so it’s always smart to check them.
Choose Your Recipe
If there’s one thing I want you to remember from this article: Always follow a recipe.
Your recipe will tell you what size jar you need, how much produce you should get, how long it will take, and more. Every step is designed with your safety in mind. Don’t wing it.
Step-by-Step Water Bath Canning Process
With your prep carefully completed, you’re ready to start preserving your produce. While every recipe has a few twists and turns, most follow this basic preservation process.
Step 1: Prepare Your Jars
The National Center for Home Food Preservation says jars do not need to be completely sterilized if you’re using a recipe that requires 10 minutes or more of processing. The bath that kills the bacteria in the produce will kill bacteria in and on the jars, too.
I am terrified of creating dangerous products, so I sterilize my jars. Extra cleaning doesn’t hurt anything, and it helps me stress test my glass before I put something valuable (like my food) inside.
I wash my jars in hot water and place the jars inside the canner with enough water to cover them. I then turn up the heat and let the jars come to a simmer while I prepare my recipe.
With this method, I know my jars are clean, and I know they won’t have cracks that could explode during canning.
Step 2: Prepare Your Lids
Place the lids you’ll need in a saucepan and cover them with water. Place them on a very low heat on a back burner. They don’t need to boil, but they should get warm enough to begin to activate the adhesive edges.
Step 3: Fill Your Jars
Your recipe will tell you how to tackle this step. In some cases, you’ll pack cold things (like cucumbers) into hot jars and fill them with a liquid (like brine).
In others, you’ll spoon something hot (like jelly) into your jars. Follow the recipe carefully and fill with your funnel and ladle.
Your recipe will also tell you how much headspace you’ll need at the top of your jar to allow food to expand as it cooks.
When I was new to canning, this was a step I often got wrong, and a ruler was my best friend. Now, I still measure with a ruler, but I’ve gotten really good at eyeballing the distance.
Step 4: Release Air Bubbles
Air bubbles trapped inside your jars create space for bacteria. Run a bubble remover (or a knife) around the inside of your jar, pausing as needed to allow gasses to release to the surface.
Step 5: Wipe the Rims
Dampen a paper towel in water and run it around the top of your glass. Your goal is to remove any debris from the surface so the lids will have something clean to stick to.
Step 6: Apply the Lids and Rings
Using your lid lifter, pull your lids from their warm water bath and apply one to the top of each jar. Tighten the rings to keep those lids in place.
The rings should be “finger tight,” or screwed down enough to stay in place but not so much that they could buckle the lids or damage the glass.
Step 7: Process the Jars
Place your jars inside the canner’s rack and lower them into the boiling water below. You should have enough water to completely submerge the jars and cover them with an inch of boiling water.
Adjust Processing Time For Altitude
Your recipe will tell you how long they should process. Typically, those recipes are designed for people living at a standard altitude. However, if you live at a high altitude, you’ll need to make adjustments.
According to the South Dakota State University Extension, these adjustments are required:
- · 1,001 to 3,000 feet above sea level: Increase processing by 5 minutes
- · 3,001 to 6,000 feet above sea level: Increase by 10 minutes
- · 6,001 to 8,000 feet above sea level: Increase by 15 minutes
- · 8,001 to 10,000 feet above sea level: Increase by 20 minutes
Remember that heat kills pathogens and that heat comes from boiling water. Set a timer and resist the urge to pull out the jars too soon.
Step 8: Let Jars Cool
Once your timer dings, remove the lid from your canner and turn off the heat. Let the jars sit for 5 minutes to allow the pressure inside to stabilize.
After 5 minutes, carefully remove the jars from the canner with your jar lifter. Place them on a cutting board and leave them completely alone for 24 hours to cool.
Step 9: Test and Label
Remove the ring from each jar, and run your finger across each lid. You shouldn’t hear anything like a pop or click, and the surface should seem tight and slightly sucked in.
I typically place the rings back on my cans at this point, as it makes stacking them for storage a little easier.
After Canning
The USDA says home canned foods should be used within a year. While some types of foods (like tomatoes and fruit) can stay good for as long as 18 months, the longer they rest, the more vitamins they lose.
Store your cans in a cool, dry space. I use my basement. I place my canned goods back in the boxes the cans came in, and I store them with the oldest items at the front. I can grab and go, knowing I’m always eating the right things first.
Don’t rely on your memory regarding what’s in each can and when you put it there. Once you get the canning bug, you’ll have so many cans that keeping track will be tough. Always label what’s inside and the date. Your future self will thank you.
Frequently Asked Questions (FAQs)
Can I use a water bath to can low-acid foods if I add vinegar?
Sometimes! Picking recipes (like those for pickles and pickled beets) use vinegar to preserve low-acid vegetables. However, don’t assume that you can just toss all veggies and grains with vinegar and can them safely. If you can’t find a trusted recipe, don’t try it.
What happens if a jar doesn’t seal properly?
Everyone (including me) deals with seal failures from time to time. Place these jars in the refrigerator and eat the contents within a day or two.
Is it safe to reuse lids and jars?
It’s totally safe (and totally recommended) to reuse jars that are specifically made for home canning projects. However, it’s not safe to reuse jars that surround products (like spaghetti sauce) made commercially. These jars aren’t designed for repeat use.
It’s never safe to reuse lids. They’re made for one use only.
Can I change a recipe if I want to?
I’ve mentioned sticking to a recipe over and over again, and there’s a really good reason for that. As the Penn State Extension explains, changing a recipe can come with unintended consequences.
For example, swapping apple cider vinegar for white vinegar could change the acidity and make the product unsafe.
New canners: Don’t get creative.
Easy Canning Recipes for Beginners
- Simple Whole Strawberries
- Super Simple Applesauce
