Stewed tomatoes have enough natural acidity to be safely canned in a boiling water bath, though adding lemon juice or citric acid boosts safety margins. If you want to know how to can stewed tomatoes without a pressure cooker, a boiling water bath canner is all you really need. This guide walks you through the whole process, from picking the fruit to hearing those lids seal.
The method is simple, affordable, and perfect for anyone with a big garden harvest or a bulk store deal. You do not need fancy equipment. A large pot, some jars, and a bit of patience will do the job.
Why A Boiling Water Bath Works For Stewed Tomatoes
Tomatoes sit right on the line between high-acid and low-acid foods. Most varieties have a pH below 4.6, which is the safe cutoff for boiling water canning. That is why so many home canners process them without a pressure cooker.
Modern tomato varieties are less acidic than older ones, though. So the USDA and extension services recommend adding acid to every jar. This small step keeps your stewed tomatoes safe for years.
- Bottled lemon juice: 2 tablespoons per quart jar
- Citric acid: 1/2 teaspoon per quart jar
- For pint jars, use half those amounts
Do not skip this. It is cheap insurance and it barely changes the flavor.
How To Can Stewed Tomatoes Without A Pressure Cooker
Here is the full process, broken down into clear steps. Read it once before you start so you know what is coming.
Step 1: Gather Your Equipment
You need a few basic items before you begin. Most kitchens already have some of them.
- A boiling water bath canner or a large stockpot with a lid
- A rack that fits inside the pot to keep jars off the bottom
- Glass canning jars, washed and inspected for cracks
- New two-piece lids and clean screw bands
- A jar lifter, funnel, and ladle
- A large bowl of ice water for peeling
If you dont have a rack, you can use a folded towel. Just make sure jars never touch the bare bottom of the pot.
Step 2: Prepare The Tomatoes
Start with firm, ripe tomatoes. Wash them well under running water. Remove stems and any bruised spots.
To peel them easily, cut a small X on the bottom of each tomato. Drop them into boiling water for 30 to 60 seconds. Then move them straight into the ice water bath. The skins will slip right off.
Core the peeled tomatoes and cut them into quarters or chunks. Set them aside in a big bowl.
Step 3: Stew The Tomatoes
Now you cook them down a bit. This step gives stewed tomatoes their soft texture and rich taste.
- Put the chopped tomatoes in a large saucepan.
- Cook over medium heat and stir often so they do not stick.
- Simmer for 10 to 20 minutes, until the tomatoes are soft and heated through.
- Add salt if you like, about 1/2 teaspoon per quart. Salt is for flavor only, not safety.
You can also add chopped onion, garlic, or green pepper. Just keep the total amount of these low-acid extras small. Too many and the acid balance changes.
Step 4: Fill And Acidify The Jars
Get your jars hot before filling. You can keep them in a pot of simmering water or run them through a dishwasher cycle.
- Add the lemon juice or citric acid to each hot jar first.
- Pack the hot stewed tomatoes into the jars with a funnel.
- Leave 1/2 inch of headspace at the top.
- Run a plastic knife or bubble tool around the inside to release air pockets.
- Wipe the jar rims with a clean, damp cloth.
- Place a lid on each jar and tighten the band until it is fingertip tight.
Do not overtighten. Air needs to escape during processing.
Step 5: Process In The Boiling Water Bath
Fill your canner halfway with water and start heating it. Put the filled jars on the rack and add more hot water until it covers the jars by at least 1 inch. Do not pour cold water on hot jars.
Turn the heat to high and put the lid on. Once the water reaches a full rolling boil, start your timer.
- Pints: 35 minutes
- Quarts: 45 minutes
These times work for altitudes up to 1,000 feet. Above that, add 5 minutes for every 1,000 feet of elevation.
Keep the water boiling the whole time. If it drops, add more boiling water, not cold.
Step 6: Cool, Check Seals, And Store
When the timer goes off, turn off the heat and take the lid off. Let the jars sit in the hot water for 5 minutes. Then lift them out with your jar lifter and set them on a towel or cutting board.
Leave them alone for 12 to 24 hours. You will hear pings as the lids seal. After a day, press the center of each lid. If it does not move and curves down, the seal is good. If it pops up and down, it did not seal.
You can put unsealed jars in the fridge and eat them within a few days. For sealed jars, remove the bands, wipe them clean, and label them with the date. Store in a cool, dark place and use within 12 to 18 months.
Common Mistakes To Avoid
Even careful canners run into problems. Watch out for these.
- Skipping the added acid because you think your tomatoes are tart enough
- Using jars with chips or cracks, which can break in the canner
- Forgetting to adjust for your altitude
- Packing tomatoes too tightly with no headspace
- Reusing old lids that have already been sealed once
One more tip. If you are new to canning, do a small batch first. Six jars is a good test run. You will learn the rhythm without wasting a whole harvest.
Once you get the hang of it, this becomes a yearly routine. Your pantry fills up, your winter soups and stews taste better, and you save money too. All without ever pulling out a pressure cooker.