It’s canning season again and for us that means lots and lots and lots of hours of food prep and processing in the canning pot. So today I thought I would share how to can whole tomatoes.
This was our first “big” canning adventure for the year, earlier I canned some jams and froze some peas. So for the tomatoes, we headed out to our local u-pick farm and picked four bushels of tomatoes. We picked two bushels of Roma tomatoes for canning whole and two bushels of field tomatoes for roasting.
Once we got the tomatoes home it was time to wash and sort.
The next step is to get some water boiling on the stove for blanching the Roma tomatoes to get the skin off. You don’t have to remove the core before blanching, but I found that it was easier to just remove it beforehand and it didn’t affect the taste of the tomatoes at all.
So for blanching, you want to boil the tomatoes for 30-60 seconds, or until the skin splits. This process could be longer or shorter depending on how ripe your tomatoes are. Some of our tomatoes were just newly red so they were kind of tough and needed a little extra blanching time. Once the skin splits plunge the tomatoes in ice cold water to stop the cooking process and then remove the skins. The skin should come off easily but if you have some stubborn tomatoes like we did just using a paring knife to help it along.
While you’re prepping your tomatoes, you’ll want to wash and sanitize all your jars and lids. There are a few methods for doing this. Here’s what I do:
- Wash and sanitize jars in my dishwasher
- Keep the jars warm in my oven at a temp of 220ºF
- Heat the lids in a pot on the stove with a TBSP of vinegar (I have hard water and this prevents the lid from developing a calcium build up)
That’s it. You can keep the jars warm in your canning pot in hot, but not boiling water, but when you’re processing this amount of tomatoes you simply can’t use your canner for this.
So now that your tomatoes are ready and your jars are washed, sanitized and hot, it’s time to stuff your jars full of tomatoes. I quarter my tomatoes before putting them in the jar, but you can leave them whole, or just cut them in half, either way you’re going to stuff those jars with as many tomatoes as possible leaving a 1/2″ of head space. Feel free to squish them down and let some of those natural juices fill the jars. This is why I like to raw pack without water, they will also produce more juices in the canner.
After you stuff the jars full of those beautiful tomatoes you have to remove any air bubbles that might be present. If you don’t you risk your jars breaking during processing in the canner, as the sealing of the jars is all about creating a vacuum.
Because tomatoes are a low-acid food you also need to add some acid, I added bottled lemon juice, they suggest using the bottled lemon juice because the acid levels in fresh lemon juice are not consistent. I added 2TBSP for each Quart/Litre jar and 1TBSP for each Pint/half Litre jar. Check to make sure you still have no air bubbles.
Wipe the rims of the jars and then put on the hot lids and rings and place them in your canning pot. (Follow the directions for your particular canner.) You can use either a water bath canner or a pressure canner. I use a pressure canner because it drastically reduces the amount of time required to process the tomatoes. For my pressure canner with a 15lb weight, I process for 15 minutes. (I follow the USDA Complete Guide to Home Canning recommendations) Processing times vary depending on your elevation so be sure you know what elevation you are at.
After the jars have been processed you need to let your pressure canner cool down completely before you can take out the jars of food. Mine takes around 30 minutes to cool and depressurize. Now you can take your jars out and let them cool on the counter or a table for at least 24 hours. After this time is over you can remove the rings and give the jars a final wipe down to remove any residue from the canning process. Your jars are now ready to be moved to your storage location.
Look how beautiful these are! When they come out of the canner the jars will look very full, eventually they settle down and look like the jars pictured above.
We used slightly less than a bushel of Roma tomatoes and processed (25) quart jars and (24) pint jars. You can use these jars just like you would any can of diced or whole tomatoes. And I can tell you they are amazing!
What vegetables do you preserve from the harvest?