Canning Tomato Sauce

Canning tomato sauce unseasoned is a great idea. It is handy to have on hand for soup bases, or spaghetti sauce, in chili, and in stews.

When I am canning tomato sauce I use Roma tomatoes and end up with about 7 quarts. This will vary according to the type of tomatoes you have.

Meatier tomatoes like the Roma tomato will give a thicker sauce. Juicier Tomatoes will have to be cooked down more to thicken.


Gather your canning supplies
  • 30 pounds Tomatoes
  • bottled lemon juice
  • salt if desired


Wash tomatoes and remove stems and bruised portions.

You'll need to remove skins.

Removing seeds is optional. When I'm canning tomato sauce seeds don't bother me for things like spaghetti sauce or stews and chili. But I would not want seeds in something with a smoother consistency like ketchup or tomato soup. Depending on what your use is for the sauce you may leave the seeds if you like.

You can prepare your tomatoes with a blender, food mill or by blanching your tomatoes and skinning them that way.

I'll explain the options. Then continue at the bottom for cooking and processing time.

Option 1 - Blanching tomatoes to remove skins

canning tomatoes blancherThis option will remove the skins but not the seeds.

This is easiest done in a blancher. If you don't have one you can just use a slotted spoon and a big pot of boiling water.

Blanch 4 to 6 tomatoes at a time. Depending on the size of the tomato. In the example pictures I am doing Roma Tomatoes. I like them for canning because they are meatier than other tomatoes. They are smaller so I can fit more in the blancher.

1- Wash tomatoes and dip in boiling water for 30-60 seconds or until skins split. You will often see the skins separating.

canning tomatoes blanching

2-When you remove the tomatoes, drop immediately into sink or bowl of cold water to stop the cooking.

3-Slip off skins and quarter tomatoes. The skins should just slide off in your hands.

Occasionally I'll use a knife on some stubborn spots.

canning tomatoes skinning

Tip - I like to have two pots set up in my double sink. The one on the left for the cold water to cool the tomatoes as they come out of the blancher. The one on the right to slide the skins off into. The pots are lower than if you set them on a counter which is easier on the arms and the sink makes for easy clean up.

As you skin the tomatoes slice them into a pot where they will be simmered.

Option 2 - Skinning and seeding tomatoes with a food mill

This option removes both skins and seeds.

Another way of preparing your tomatoes for canning spaghetti sauce is to use a food mill. This is my preferred method. But if you don't have a mill the blanching described above will do the job too.
canning tomatoes in pot

First wash your tomatoes in cold water then slice in half. Simmer the tomatoes to make them softer for the food mill.

canning tomatoes simmeringIt is easier to do this if you have some juice in your pan to start.

Place a single layer of tomatoes in a pot to simmer. As it heats, use a potato masher to crush tomatoes to draw out the juices.

When you have a bit of juice in your pot, continue slicing tomatoes in half and adding to the pot.

When all tomatoes are sliced, simmer for 20 minutes or until tomatoes are juicy and heated through.

canning tomatoes squeezo

I used two large pots to simmer 30 pounds of tomatoes.

With the tomatoes split into 2 groups it is less likely to scorch.

Put tomatoes through the food mill. This removes all skin and seeds.

Option 3 Use blender to liquefy tomatoes.

This option does not remove the skins or the seeds.

To do this you simply wash the tomatoes remove the stems and pop them a few at a time in the blender. Blend until smooth. Quick and easy.

Ready to use:

Bring to a boil.

Simmer, uncovered to thicken. Cook until it reaches your desired consistency. Stir frequently to avoid burning!! The amount of canned tomato sauce may be reduced by nearly one-half.
  • An easy way to do this is to place sauce in a slow cooker and leave the lid off. Let it cook until thickened.
  • OPTIONAL: you may also can this as is, without cooking to thicken. Later when you use the jar, sauce will be thinner.
Here is my favorite time saving tip

Your Sauce is now ready to use in other canning recipes like spaghetti sauce.

To process the sauce just as is: Fill hot jars, leaving 1 inch head space.

My suggestions is to follow pressure canning instructions.

Canning tomato sauce may also be water bath canned if you add lemon juice to each jar to acidify the tomatoes. Quarts get 2T and pints get 1 T. See canning tomatoes safely for more information.

Be sure and adjust your processing to your altitude.


Process Pressure Canner -
Pints 15 minutes, Quarts - 20 minutes

Adjustments for Pressure Canner
Altitude in Feet Dial Gauge Canner Weighted Gauge Canner
0-1000 10 10
1001-2000 11 15
2001-4000 12 15
4001-6000 13 15
6001-8000 14 15
8000-10,000 15 15

Process Water Bath Canner -
Pints -35 minutes, Quarts 40 minutes

Altitude Adjustments for Boiling Water Bath Canner
Altitude in Feet Increase processing time
1001-3000 5 minutes
3001-6000 10 minutes
6001-8000 15 minutes
8001-10,000 20 minutes

Canning Tomato Sauce with this recipe is a great way to be stocked up and ready for a quick meal.

Tomatoes and Tomato Products

Tomatoes Whole or Halved

Spaghetti Sauce

Spaghetti Sauce(meatless)

Stewed Tomatoes

Unseasoned Tomato Sauce

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Canning Books by Sharon

I have attempted to share safe preserving methods. However, I make no promises. You alone are responsible for your health. Be aware of current safety recommendations.
See my Full Disclaimer here.