The Water Bath Canned Tomatoes method is the easiest way to preserve tomatoes
I love growing, preserving, and eating tomatoes. Every year I grow way more tomatoes than my family could possibly eat. By canning my tomatoes in a water bath, I can enjoy my garden tomatoes all year long. Besides one or two specific recipes, I haven’t bought canned tomatoes in at least seven years. The below guide will walk you through the basic steps and pitfalls of water bath canning.
Is it safe to water bath canned tomatoes?
Canning tomatoes via a water bath is a safe and effective method to preserve tomatoes. The method has been around since at least the 1800s when canning was first developed. There are a lot of rules, tips, and tricks for getting the perfect canned tomato, but the rules are pretty straightforward to follow.
I often rely on my local extension school (in this case Michigan State) for guides and resources on how to preserve my yearly garden vegetables. There are a lot of guides on how to preserve tomatoes, but I found this to be a particularly useful reference guide.
Should I remove the peels before canning tomatoes?
Removing tomato peels is a matter of personal preference that won’t affect the quality of the preservation. I’ve made canned tomatoes with and without peels before, and find that the only reason you might leave your peels on is to save time.
Generally I prefer to remove the peels. Leaving the peels on means they will show up in your finished meals, and tend to be visually unpleasant. If you don’t want bits of rolled up peels in your spaghetti sauce, it’s worth taking an extra hour to blanch your tomatoes.
How to blanch tomatoes for water bath canning.
Blanching is the most straightforward and reliable way to remove the peels from tomatoes. Start by coring the tomatoes, and then score the tomato with an X on the opposite side. The scored X will give you easy places to grab and pull the peel off. You can also cut off undesirable chunks of tomato at this point.
While you process the tomatoes, start a boiling pot of water that preferably can hold 5-6 tomatoes at a time. Set up a roughly equivalent sized pot of cold water next to it.
Once you’re done coring and scoring tomatoes, and the water is at a boil, you can start blanching. Boil the tomatoes in batches for 60 seconds, and then scoop them over to the cold water pot. After another minute in the cold water pot, remove them and pull off the peels. They should be loose and easy to pull off.
You may have to replace the cold water pot depending on the number of tomatoes and the size of the pot.
How to adjust the pH of your Water Bath Canned Tomatoes
A low pH will help keep bad things from developing in your canned tomatoes. The University of Georgia suggests targeting a pH below 4.6 when using a water bath technique.
Since tomatoes are already near a pH of 4.6, you can push it into the safe zone by simply adding a quarter teaspoon of citric acid to each can. It won’t affect the flavor or texture of the tomatoes, but will help ensure the success of your water bath canning.
How long to water bath tomatoes
This recipe follows the cold-pack method of water bath preservation. That means the jars are loaded with cold or room temperature tomatoes, and boiled in water for an extended period of time. (This is opposed to a hot pack, where you boil jars of hot cooked tomatoes for less time.)
Preservation is a matter of killing off harmful microbes via temperature and time. The higher the temperature, the less time is needed to kill off the microbes. Water baths work by boiling water, and water boils at different temperatures depending on altitude. The length of time you need to boil your jars depends on your altitude. Here is a table of altitudes and times:
Altitude | Boil Time |
0-1000ft | 85 Min |
1000-3000ft | 90 Min |
3000-6000ft | 95 Min |
6000+ ft | 100 Min |
If you’re unsure of your altitude, you can quickly google your location plus “altitude” to find out.
Should I leave the bands on canned tomatoes?
The prevailing, safest, opinion is that you should take your bands off the tomato jars after they’re done in the water bath. There are a few reasons to remove the bands from your tomato cans:
- Bacteria and other nastiness can build up between the band and the glass. The band is not airtight, so there’s no guarantee it’ll stay clean.
- The band obscures problems during canning. If there was a problem with the can sealing (it happens), you might not notice it with the band on.
- The band obscures problems after canning. If the jar gets knocked and the lid comes loose, the band might trick you into believing the jar is still sealed.
All of that aside, it probably isn’t a big deal if you leave the bands on your cans, so long as you are observant when opening the cans.
Tips and tricks for filling your jars
- Leave at least ½” of head room at the top of the jar. If you overfill the jar, it’ll burst while boiling.
- Work out air bubbles. I run a butter knife around the inside and through the middle of my jars to push out any unseen air pockets. You’ll be surprised at how much space opens up after removing the air.
- Add some herbs. You can add a subtle and pleasant flavor to your tomatoes by adding a couple herb leaves to each jar. I usually add some fresh basil to mine.
- Invest in a pair of jar tongs. You can find them on amazon or at most big box stores. They’re sized to perfectly grab Ball jars, and will make it way easier to pull the jars out of the pot after boiling.
- Use the right size pot. Your pot should allow for a couple inches of water above the tops of your jars.
Tips and tricks for Ball jar lids
Water bath canning is part art, part science, and part culinary. I have a few random tips and tricks on working with Ball jars that might help you:
- Unseal your jars with a spoon. If you have trouble getting sealed Ball jars open, try prying it up with a spoon along the lip of the lid. Once you break the seal the lid falls off.
- Write on your lids. If you’re like me, you have several types of canned tomatoes that may even span more than one season. Use a permanent marker to mark the type and date of your tomatoes on the lid.
- Don’t reuse lids (for preservation). Ball jar lids are not intended to be re-used in preservation. They have a waxy ring around the outside that is only good for one water bath canning. Most stores that sell Ball jars sell replacement lids. At this point, lids are the only thing I need to buy each year.
- Do reuse your lids (for non preservation things.) If you want to freeze a jar of sauce, or keep something in the fridge, you can totally re-use a Ball jar lid with a band. Just don’t try to re-seal the jar with a used lid.
Meals to make with Water Bath Canned Tomatoes
I use my canned tomatoes everywhere. Pretty much any tomato based recipe you’ll see here uses my canned tomatoes. Some of my favorite meals using canned tomatoes includes:
By the way, did you know that you can preserve smoked tomatoes? I have a guide on smoking tomatoes, I promise you won’t regret it.
Guide for water bath canned tomatoes
Water Bath Canned Tomatoes
Equipment
- 1 Large stock pot Big enough to hold your jars plus 2" of head room
- 12 Ball jars Use as many and as many sizes as you need, but use fresh lids.
- Star San Optional sterilizer
Ingredients
- 10 lb Tomatoes As many tomatoes as you want
- ¼ tsp citric acid per jar
- 1-2 leaves basil, oregano, thyme Optional, per can
Instructions
Blanching instructions
- Start by coring your tomatoes and scoring each with an X. Start a pot of water boiling, big enough to hold a batch of 5-6 tomatoes. Set up an equal size pot of cold water next to it.
- Boil tomatoes in batches for 60 seconds. Then move them to the cold water pot.
- After a minute in the cold water, remove the tomatoes and pull off their peels. Repeat the process until all tomatoes have had their peels removed.
Jar Filling Instructions
- Start by cleaning your jars with soap and water.
- Optionally, fill each jar with water and add a teaspoon of Star San, and let them sit for a couple minutes. Star san is a sterilization agent used by brewers to sterilize equipment. It's nice because it doesn’t need to be rinsed again, just dump the water out before adding tomatoes. You can also sterilize the lids and bands by submerging them in a bowl with star san and water.
- Make any final preparations for the tomatoes. Slice them, dice them, or jar them whole.
- Fill each jar up to a half inch of the rim. Use a knife to agitate and remove any air from the jar, and add more tomatoes if needed. The tomatoes should be submerged in liquid, add a bit more if needed.
- Add a quarter teaspoon of citric acid to each jar. If using lemon juice, just a full teaspoon per jar. Also add any fresh herbs like basil if you plan to include them
- Seal each jar with a fresh lid and band. Make sure the band is firmly attached, though not over tight.
Water Bath Instructions
- Prepare your pot for the water bath. Put a rubber spacer at the bottom of the pot to keep the jars from direct contact with the bottom of the pot. Then add your jars and fill the pot until the water level is a couple inches above the jar lids.
- Heat the pot on high heat until it reaches a boil, then reduce heat so that it stays boiling without boiling over. Follow the table up above for how long you need to boil for.
- If your water level drops too low during the boiling, carefully supplement with more boiling water.
- Once the boiling time has passed, carefully remove the jars from the pot and set them on hot pads or towels to cool overnight. You’ll hear “pop” sounds as they cool and the lids seal. Store the jars at room temperature and use as needed. Enjoy 🙂
