Standard Tomato Sauce

From the USDA Complete Guide to Home Canning, 2009 edition

Whole tomatoes
Lemon juice

A bushel of tomatoes weighs a little more than 50 pounds and will produce 10-12 quarts of thin tomato sauce. The thicker you make your sauce, the lower the yield.

Wash, remove stems and trim off bruised or discolored portions from tomatoes. Cut a good portion of the tomatoes into quarters and put directly into a large, hot saucepan and crush them with a potato masher. Continue to slowly add and crush freshly cut tomato quarters to the mixture, stirring occasionally.

Simmer for another five minutes, then remove from heat and press the heated tomato mixture through a medium sieve or food mill to remove skins and seeds. Return to heat, simmer and reduce the sauce until you reach the desired consistency.

Add 2 tablespoons lemon juice to clean, hot quart-sized canning jars, adding salt if you like. Fill hot jars, leaving 1/4-inch headspace. Remove air bubbles and adjust headspace if needed. Wipe rims, apply lids and rings and process in a boiling water canner for 45 minutes.