Cooking with tomatoes is one of my favorite activities, so knowing how to pressure can tomato sauce is essential sometimes. If you don’t know how to pressure can certain vegetables or fruits, your product can turn out badly.
Let’s cover the basics first.
What is pressure canning?
Pressure canning is the method of canning that uses a piece of equipment with a vent, a pressure gauge, and screw clamps. This pressure canner can heat food to very high temperatures, which pressurizes the jars enough to make the product safe.
But, why do I need to use a pressure canner?
One thing I learned pretty quickly when I began my trip into home canning is that some foods are not safe to can with a water canner. As a rule of thumb, any food that is low in acid—or alkaline—will need to be canned using a pressure canner.
In this case, tomatoes are not too alkaline, but they aren’t acidic enough, which means it’s always better to pressure can them. The reason to use a pressure canner is to prevent the possibility of botulism or any other microorganism growth.
Now that we got the technicalities out of the way, there are
The 6 tips to learn if you want to know how to pressure can tomato sauce:
Tip #1: Wash and remove the skins from your tomatoes
While removing the seeds isn’t entirely necessary when you are canning tomato sauce, you do need to remove the skin. The first way to do this safely is to blanch a few tomatoes at a time. You should start by washing them, dipping them in boiling water for less than a minute, or until the skins come off. You should then immediately drop them into a bowl of cold water or ice. Finally, peel off the skins and then cut your tomatoes.
Another option here would be to use a food mill, which would remove the seeds and skins at the same time. To use it, first, wash the tomatoes, then slice them in half, and simmer them for a bit to make them softer. You can then place the tomatoes in a pot and mash them to draw out the juice. Continue slicing tomatoes and adding to the pot. Simmer for about 20 minutes and finally place them through the food mill.
The final option here is to place all your tomatoes in a blender. Keep in mind that unless you have a very strong blender, this option will only mash and liquefy, but not remove the seeds or skin.
Tip #2: Once seeded and peeled, it is time to cook your tomatoes
To begin, bring your tomatoes to a boil, and then turn the heat to medium. Remember to stir often, otherwise, you may allow scorching. Sometimes, I have a ton of tomatoes, so my sauce will be thick and requires more stirring.
Allow your sauce to get hot and bubbly, but if you want a thicker consistency, continue to cook for a while. The longer you cook, the less liquid you’ll end up with.
Tip #3: Add lemon juice while you cook
While not everyone thinks adding acid is essential, I like to use a bit of lemon juice in my tomato sauce. I do this because it keeps the flavors, colors, and texture right after processing. Also, it gives the sauce a touch of tartness that is always good.
I add about 1 tablespoon of lemon juice per pint jar, and 2 tablespoons if the jars are bigger. You can add lemon juice when pouring the tomato sauce into the jars, or before it if you prefer.
Tip #4: Make sure your jars are ready to go
A rookie mistake when pressure canning is preparing the jars a bit too late. For your tomato sauce to be canned properly, your jars have to be settled and ready to go in the pressure canner.
When you use a pressure canner, you don’t necessarily need to sterilize and pre-heat your jars, but it can be a good idea to wash them beforehand. Once ready, set your jars on the rack in the pressure canner and ladle in the tomato sauce.
Tip #5: Process your jars appropriately
This part is tricky for everyone, but it is important to keep in mind that processing varies depending on your altitude. I usually go with pint-sized jars, so I process them for about 20 minutes at a time.
Tip #6: Let your jars cool down and store them in the fridge
I tend to leave my jars aside in a cool, dark place for about 12-24 hours. I do this because the sauce can spoil if stored too quickly. Remember to check the seal and that the lid remains firm when pressed down.
Once cool, I store my jars in the refrigerator for use whenever I want. Another quick tip is that the tomato sauce can be stored in the freezer to last longer.
Enjoy your home pressure-canned tomato sauce now that you are an expert at it!