Wash tomatoes thoroughly
Remove stems and blemishes
Cut tomatoes into quarters
Simmer tomatoes until soft
Crush or blend the tomatoes
Strain through a food mill or sieve
Reheat the juice to a boil
Add bottled lemon juice or citric acid if needed for acidity
Sterilize canning jars, lids, and bands
Fill hot jars with hot tomato juice, leaving proper headspace
Remove air bubbles
Wipe jar rims clean
Place lids on jars and secure bands fingertip-tight
Process jars in a boiling water bath or pressure canner according to tested guidelines
Remove jars and let cool undisturbed
Check seals after 12 to 24 hours
Store sealed jars in a cool, dark place