How to Can Tomato Sauce

Post by Olivia Martino, Registered Dietitian and Co-Owner, Nourish Northwest


Let me start by saying I am no expert when it comes to canning.  Many people have been doing this for decades as a means of budgeting and preserving the season’s bounty.  There are TONS of resources on the internet, as well as books you can buy.  I found the Ball Jar website to be particularly helpful.  This post is by no means the most comprehensive set of guidelines out there but this is what I know so far, in my second year of canning and it appears to be working!  My method involves no special canning equipment, which might make it a little more challenging but is ideal for the novice who doesn’t want to invest much.

What happens when you have a kitchen garden, is that your are never sure exactly how much produce you are going to grow.  Every year you learn a little more about your errors and how you can do better the next year but there are variables you can’t always control, such as weather and pests.  Jut a few weeks ago I was really worried that our tomatoes were never going to ripen and now all of a sudden we have a billion delicious juicy little guys.  As I wrote about in a previous post, my favorite way to enjoy them is fresh.  But we have way to many and we are about to go on vacation.  Time to start canning!

Lots of tomaters!
Lots of tomaters!  Sungreens, green zebras and red heirlooms

Marcella Hazan’s Tomato Sauce Adapted for Canning

Awhile back I posted this recipe for my favorite tomato sauce.  Unfortunately this isn’t canner friendly because it has butter in it.  The solution: make it without and then add in when you are ready to eat!  I used sun green tomatoes, but traditionally this sauce would be made with a larger red tomato variety.


15 lbs. fresh ripe tomatoes, washed
1 Tablespoons olive oil
6 cloves garlic, finely chopped
3 onions
1 Tablespoon lemon juice per pint jar
1 Tablespoon salt
1 teaspoon pepper

5 pint sized jars and lids that have not been used

Step 1: Sterilize the jars

First you want to wash the jars with warm soapy water.  Then fill them with water and place them in a large pot.  Fill the pot with water and cover the jars by 1/2 inch.  Bring to a simmer.  Keep in hot water until a few minutes before ready to fill.  Carefully remove jars with kitchen tongs and place face down on a clean dish towel.  This year I did decide to buy special canning tongs, which made grabbing the jars a whole lot easier.

Canning tongs... just a few dollars on Amazon
Canning tongs… just a few dollars on Amazon

Sept 2: Peel the tomatoes

Bring a large pot of water to a boil.   Remove stem from tomatoes and make an “x” in the bottom of each tomato with a knife.  Prepare an ice bath to place near to the stovetop.  Carefully drop 5-6 tomatoes at a time into the boiling water, cook for one minute and then plunge into ice bath.  Repeat with remaining tomatoes.  When the tomatoes are cool enough to handle, the skins should peel off easily.  


Making "X"s in the tomatoes allow the peel to come off easily
Making “X”s in the tomatoes allow the peel to come off easily


Sept 3: Make Your Sauce

Add 2 T. olive oil and the chopped garlic to a large pot. Heat until it sizzles, then add the chopped tomatoes.  When it starts to simmer use a potato masher to break down the tomatoes to a lumpy pulp.

Hold the onions root end up and cut in half, so that each piece is anchored by the root bundle. Peel off the papery skins and place the halves into the sauce. Stir in the salt and pepper.

Simmer the sauce for 30 minutes or until it is reduced by about half.

Step 4: Can That Yummy Stuff!

Bring the pot of water that you used to sterilize the jars to a boil.  Add more water if necessary; you will want to cover the jars by a 1/2 inch to an inch again.  Add 1 Tablespoon of lemon juice to 5 freshly cleaned pint jars (the lemon juice is to make the sauce acidic enough, so that bacteria won’t grow.  Alternately you can test the pH of the sauce and if it is below 4.5, no lemon juice is necessary). Remove the onion halves from the sauce. Fill the jars with the hot sauce, leaving 1/2 ” headspace, seal with clean lids and bands.  Place jars in  a boiling water bath for 35 minutes. 

When done, carefully remove jars from the pot. Let cool, undisturbed for 12-24 hours  You may hear a popping sound as they rest on the counter, this is a good sign that your seal is in place.  If you press on the jar lid and it bounces back your sauce did not properly seal.  Place any unsealed jars in the fridge and eat soon.  All sealed jars can be store in a cabinet until ready to use.

All canned up for the winter!

Step 5: Reheating the Sauce

When ready to eat, pour one pint of the sauce into a small pot and bring to a simmer.  Add 4 Tbsp butter.

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