Canning tomatoes is a great way to preserve the summer harvest. The process is extremely easy, and included is a video tutorial on preserving tomatoes.
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The most preserved item during canning season is the tomato. Whether the goal is to put-up salsa, sauces, or the basic tomato canning tomatoes is an extremely easy process. Today’s topic is preserving the basic tomato, and the decision which needs to be made is whether to hot water bath or pressure can them. Where does your comfort level lie?
Who doesn’t love a good tomato? In truth, the tomato it is the most versatile item to be preserved. Think of all the amazing items which can be made from them fritatta, casserole, stew, soup, sauces, omelets, and for making homemade soups. Additionally, there is absolutely nothing quite as rewarding than consuming the fruit of summer in the dead of winter.
This my friends is why we garden and why we preserve foods. Home food preservers know each and every ingredient in the jar.
Does it get any better than this? I think not.
Selecting the best tomato variety
Look, when selecting the right tomato there’s no science to it, and in truth it’s really based on preference and what is prolific in the garden. However, with that said, when canning tomatoes (whether in whole, sliced, diced or crushed) the Roma or plum tomato is a great choice.
Roma tomatoes are a meatier variety with little seeds, it holds its texture well during the preparation and canning process making it a great option to be canned. Not only is the Roma a great item for canning the basic tomato it is excellent for making canned items such as tomato, pizza, and chili.
No matter how you look at it tomatoes are low in acidity, regardless if it is a heirloom or hybrid variety. In order to preserve it properly the acidity level will need to be lifted, this applies when using either a hot water bath or pressure canner.
The acidity level can be increased by using either bottled lemon juice or citric acid:
- Pint jars – 1 tablespoon lemon juice
- Quart jars – 2 tablespoons lemon juice
- Pint jars – 1/2 teaspoon citric acid
- Quart jars – 1/4 teaspoon citric acid
Fresh lemon juice is not high enough in acidity needed when canning tomatoes, my suggestion is to stick to one of the two suggestion which were made.
Preparing the Fruit
The first step in preparing tomatoes for canning is to blanch them. When the skin is cooked it becomes tough and unappealing, making it difficult to enjoy the jar of food. Through blanching the skin can easily be peeled and what remains is the ‘meat’ of the fruit.
- Wash tomatoes well
- Discard any bruised or rotten spots
- Place an X on the blossom end of the tomato helps to peel the tomato if it should not crack during the blanching process.
- Finally, bring a large stock pot to boil
A blanching colander is excellent tool for blanching a large amount of tomatoes, or any fruit or vegetable, at a time.
The Blanching Process
The blanching time can take anywhere from 1 to 3 minutes, depending on how ripe the tomato is. Though if a tomato is quite ripe it can take roughly 30 seconds to 1 minute in order for the skin to separate from the meat of the fruit.
More times than not the tomato skin will crack, indicating that they have been blanched long enough. Without a doubt there will be a tomato that is stubborn and skin will not peel. Feel free to blanch it a little longer or use a knife remove the skin.
Once the blanching process is complete immediately submerge the blanching basket into ice water or extremely cold water. An ice-water bath is necessary for two reasons:
- To stop the cooking process, and
- Allow the for easily handling of the tomato in order to remove the skin
There is no exact time for how long the tomatoes should sit in the ice water. Basically, as soon as you are able to handle them is the right amount of time.
Save the peels! The peels can be made into tomato powder and used in various type of foods. The powder can also be reconstituted with water to make tomato paste. Did you get that? Homemade tomato paste by using an item which is generally discarded! Additionally, the tomato powder can be added to items which you are preparing when the flavor of a tomato is required without using a jar of tomatoes.
Canning Tomatoes – Selecting between Whole, Sliced, Crushed, or Diced
There are a few methods available when it comes to canning tomatoes. They can be preserved whole, crushed, sliced, or diced and the decision on how to put them up is based on what you plan to make with them. For this tutorial we opted to preserve tomatoes by slicing them.
For individuals who have space restraints canning whole tomatoes is not practical. Not one bit. Selecting to pack the jars with crushed, sliced or diced tomatoes allows for more tomatoes in each jar, minimizing the amount of jars in the pantry.
The Processing Method and Time
The steps for filling (otherwise known as packing) jars is the same regardless of what is being canned.
- Sterilize jars – this can be done in a dishwasher or by boiling the jars for 10 minutes, remove a few jars at a time to be filled
- Fill jars
- Increase acidity to each jar by adding 1 tablespoon of bottle lemon juice for pints, or 2 tablespoons of bottled lemon juice for quarts
- Add boiling water to each jar – making sure to leave the appropriate amount of headspace from the top of the jar to the water level
- Salt is optional, a pinch is generally all that is needed per jar
- Remove air bubbles using a bubble removing tool. Fill the jar with additional boiling water if the water level should fall below the half inch mark
- Using a clean cloth wipe the top of jars
- Add warmed lids and rings, making sure to tighten only to finger tight
- Process for the appropriate time based on the elevation in which you reside
A video tutorial of each step can be found here:
Hot Water Bath Canning (HWB)
Because tomatoes are low in acidity the processing times is much longer that what it is for canning pickles, jam, or jelly. For this reason a hot water bath canner is required verses the use of a steam canner.
Also, keep in mind because of the long processing time the water level of the canner will need to be 2 inches above the top of the jars when processing tomatoes.
Processing time for 0 – 1,000 feet
- Pints – Process for 40 minutes
- Quarts – Process for 45 minutes
The processing time for those who reside 1,001 feet or more above sea level can be found here.
Pressure Canning (PC)
Determining the correct PSI and processing time will vary based on the type of canner being used and elevation based on where you reside. For example, we reside between 0 – 1,001 feet, the processing time for the Presto dial canner is 11 pounds of pressure. However, this may not be accurate for you.
Review the manual based on the PC you own when pressure canning tomatoes . Each brand of pressure canner will have specific instructions on how the tomatoes should be canned.
The National Center for Home Food Preserve also provides the necessary processing time and PSI, review their guidelines here.
Other Methods for Preserving Tomatoes
Preserving tomatoes is not limited to canning tomatoes whole, sliced, crushed or diced. Spaghetti, chili, pizza sauce, along with salsa are all excellent options when making this fruit shelf stable.
- Whole tomatoes in basil and garlic. They make for an excellent addition to any dish.
- Freeze the tomatoes in order to slip the skins off. And in truth, it’s actually quite brilliant if you have the freezer space!
Grab a copy of my book, The Farm Girl's Guide to Preserving the Harvest.
From my farmhouse kitchen to yours, an easy to comprehend guide which walks you though every phase of home food preservation. Learn how to can, dry, ferment, cure, freeze, and storing fresh foods for long term storage. Included you will also find some of my favorite preserving recipes!