Prepare a water bath canner and canning jars/lids. I'm describing the raw pack method here, which requires a canner pre-heated to 140 degrees F. If opting for the hot pack method, preheat the canner to just simmering (180 degrees F).

Bring a separate pot of water to a boil on the stove. Dip each tomato into the water for 30 to 90 seconds, until the skin cracks. Remove from the boiling water with a slotted spoon and place in a bowl of very cold water to cool.

While the tomatoes cool, bring a kettle of freshwater to a boil to use as a canning liquid.

Once cooled, remove the tomato skins gently with your fingers. If properly blanched, the tomato skins should slide off easily.

Use a paring knife to remove the tomato cores.

Add lemon juice to the bottom of canning jars before you pack the tomatoes, using 1 tablespoon per pint or 2 tablespoons per quart. This step is NOT OPTIONAL and is required for canning tomatoes in both a water bath and pressure canner. (Citric acid and vinegar are alternatives, see notes for quantities.)

Pack tomatoes, as whole fruits or halves, into the canning jars on top of the lemon juice, leaving 1/2 inch headspace. If adding salt, the recommended amount is 1 tsp per quart or 1/2 tsp per pint, but salt is optional.

Pour boiling water over the top of the tomatoes, filling jars but still leaving 1/2 inch headspace. De-bubble jars to ensure there's no air trapped between the tomatoes and add water if necessary to maintain headspace.

Seal the jars with 2 part canning lids to finger tight.

Use a canning jar lifter to load the jars into a water bath canner. Since this is the raw pack method, the canner should have water that's around 140 degrees (hot enough to burn your hand, but nowhere near boiling).

Turn the heat up to high and bring the canner and it's contents up to a full rolling boil. Once boiling begin timing the canning process. Water packed tomatoes need to process for 40 minutes for pints and 45 minutes for quarts in a water bath canner below 1,000 feet in elevation. See notes for altitude adjustments.

Once the canning time is complete, turn off the heat and allow the jars to sit in the canner for 5 more minutes to cool slightly (this helps lower the risk of siphoning or liquid loss as they're removed from the canner).

Remove the jars to cool on a towel on the counter for 24 hours. After 24 hours, check seals and store any unsealed jars in the refrigerator for immediate use. Properly canned and sealed jars of tomatoes should maintain quality on the pantry shelf for 12-18 months.