Wash tomatoes. Dip in boiling water 30–60 seconds or until skins split, then dip in cold water. Slip off skins, remove cores, and leave whole or halve.
Add required bottled lemon juice or citric acid to each jar. Add salt if desired.
Fill jars with raw tomatoes. Press tomatoes into the jars until spaces fill with released tomato juice, leaving 1/2-inch headspace.
Boiling-water process pints or quarts 85/90/95/100 minutes at 0–1,000/1,001–3,000/3,001–6,000/above 6,000 ft.
Pressure-canning options are also tested, but acidification is still required. Follow the NCHFP dial- or weighted-gauge table exactly for your selected pressure/time combination and altitude.