Most tomatoes are a high acid food and are safely process in a water bath canner. Some modern tomatoes should be processed with lemon juice to insure acidity.
Always select firm, red ripe tomatoes. Don’t use overripe tomatoes.
It’s important that the tomatoes not be too ripe because the acidity of tomatoes declines the riper they become. Also, extremely soft or too ripe tomatoes can turn into a mushy, overcooked mess during processing if you’re not careful.
It’s my opinion that overripe tomatoes are much better suited for juice or for tomato sauce.
Here’s a short tutorial:
Collect and assemble the jars, bands, lids, jar lifter, a non metallic bubble release tool, large bowls, knife, wooden spoon and the water bath canner.
Visually examine all jars and rims for cracks, nicks or sharp edges.
Wash the jars and bands in hot soapy water. Dry the bands and set them aside. Keep the jars hot until ready to fill. I use a dishwasher for this, but you can use a sink or dish pan full of hot water, or pour boiling water into the jars and stand them in a sink or shallow pan until ready to use.
WASH THE TOMATOES
Prepare only one canner load of tomatoes at a time.
Getting the tomatoes ready for canning will take a bit of time depending upon the size of the jars and the size canner you intend to use.
The tomatoes should be washed in cool, soapy water and then rinsed to remove any garden dirt.
This can be done well ahead of time.
PEELING THE TOMATOES
The tomatoes will need to be peeled before they are canned.
Peeling tomatoes is a messy job but an easy one. It will take a bit of time. Try and coincide the heating of the water in the canner, the simmering of the jar lids and your usual canning routine for when you’ll be finished prepping the tomatoes. It may take some task juggling between preparing the tomatoes, filling and heating the water in the canner to get the timing just right.
The important thing is to have the water in the canner simmering hot at the time when you will be filling the jars.
Here’s how to peel and remove the skin from tomatoes:
To remove the skins from the tomatoes, place just a few at a time into a pot of rapidly boiling water.
Keep them in the pot until their skins begin to crack or split.
It usually takes between 1 – 3 minutes for the skin to split but sometimes it will take longer. After the skin splits on the tomatoes remove them from the boiling water and place them into a sink or very large bowl of cold water to cool down.
Peel the tomatoes and remove the core and any green parts.
Small tomatoes may be kept whole, but large tomatoes should be quartered or cut into smaller pieces so they will fit in the jar.
After the tomatoes have been prepared, and the lids have been simmered and the water in the canner is hot – it is time to fill the jars.
Salt is optional when canning tomatoes. The standard measure is 1 teaspoon for quarts and 1/2 teaspoon for pints. I use those amounts with my tomatoes.
For extra safety if you are unsure about the acidity of the tomatoes, add 2 tablespoons of bottled lemon juice per quart and 1 tablespoon bottle lemon juice per pint.
Fill a hot jar with tomatoes leaving a 1/2 inch head space.
It may be necessary to squeeze the tomatoes while filling the jars to release more juice from them.
The juice helps to achieve the proper head space. I have a small wooden masher that I use for this but a wooden spoon will work just fine.
Tomatoes tend to collect air pockets and bubbles in the jar and it’s very important to release them.
I do this by running a non metallic object or spatula down the sides of the jar.
After the air bubbles have been released, wipe the rim and threads of the jar with a clean damp cloth.
When working with tomatoes extra care needs to be taken when cleaning the rim and threads.
It is very easy to miss a seed or small piece of tomato and if a seed gets between the rim of the jar and the lid, the jar will fail to seal.
After the jar rim and threads are perfectly clean apply the lid and the screw band. Don’t over tighten the band – finger tight is good.
Place the filled jar into the simmering canner to wait on the other jars.
Fill the rest of the jars and place them one at a time into the canner until the load is complete.
Now put the lid on the canner and turn up the heat so the water can begin to boil.
With water bath canning it is important that boiling water completely cover the jars by 1-2 inches.
If more water needs to be added to the canner make sure that it is boiling water and is poured along the sides of the canner and not directly over the jars.
Processing time is counted from the time the water begins to boil. A gentle but steady boil is what you’re trying for.
Processing time for tomatoes is 45 minutes for quarts and 35 minutes for pints for altitudes at 1000 ft. sea level or less. If your location is higher you will need to make an adjustment in processing time.
Once the processing time is complete remove the jars immediately from the canner and place them on a wooden board, thick towel or heavy newspaper to cool. Leave the jars undisturbed for 8 – 12 hrs. After the jars have cooled it is important to check the seal. Remove the screw band before checking the seal.
The seal is checked by gently lifting the jar by the lid or pushing down into the center of the lid.
The lid should be slightly concave and have no spring to it.
If the lid bounces up and down the jar has not sealed and the tomatoes should be frozen, reprocessed or eaten promptly.
Often the sides of the jars will be sticky and need to be wiped clean.
As with all home canned food, store your tomatoes in a cool dark place.
Every summer I manage to get a few jars of tomatoes that don’t seal.
Most often it is caused by seeds or bits of tomato being pushed up under the lid during processing.
Above is a jar that failed to seal. If you click on the picture you’ll notice that seeds and tomato stuff is on the lid and jar rim. No wonder it didn’t seal.
When I get one that doesn’t seal, I just freeze the tomatoes by emptying the jar into in a rigid container or freezer bag.
Frozen tomatoes are wonderful in chili and in other dishes. Often tomatoes (and other fruits or vegetables) packed by the raw pack method, will tend to float in the canning jar. This is normal and no cause for concern.
Raw vegetables, fruits, meat and other foods are more dense when they are raw than when cooked.
When raw food is packed into a hot jar it doesn’t take up as much space.
The floating occurs because the vegetable cooks during processing and shrinkage occurs.
If I turn the jars pictured below is turned upside down, the tomatoes will reincorporate and there will be no floating or separation.
Floating is overcome by heating or semi cooking the food product before it’s packed into the jar.
Heating food before filling the jars is called “hot pack” and many people prefer it when canning.
The advantages to hot pack is that you can fit more food into a jar and consequently don’t need as many jars.
This is good to know if you are short on jars.
However, if you heat or cook tomatoes before filling the jars they then to fall apart and are harder to handle.
Raw packing tomatoes results in a superior product and most people use it.
You can freeze tomatoes if you don’t care to be bothered with canning or don’t have the equipment.
Prepare the tomatoes exactly as if you were going to can them – wash,peel and core them.
But instead of canning them place them into freezer bags or rigid containers. Frozen tomatoes have a much fresher taste and make for an excellent cream of tomato soup.
When frozen tomatoes are defrosted there will be separation of the tomato flesh and liquid.
You can either pour off the liquid and have a dryer tomato product, or you can turn the freezer bag or container upside down a couple of times and the tomatoes will reincorporate.
I often freeze tomatoes at the beginning and at the end of the tomato season.
That’s because when tomatoes first come on in the garden there usually isn’t enough to make a full canner load. Same thing at the end of the season.
Freezing rather than canning tomatoes is a much more sensible and energy-saving option if you have just a few pounds of tomatoes to work with.