Salsa can be a fun and easy way to preserve tomatoes to enjoy all year. Use only high quality tomatoes for canning salsa. Canning is no way to use overripe or damaged tomatoes, nor tomatoes from dead or frost-killed vines.
The type of tomato you use affects salsa quality. Paste or Italian tomatoes have a firmer flesh and produce thicker salsas than large slicing tomatoes.
Use only high quality peppers. Do not increase the total amount of peppers in any recipe. But you may substitute one type of pepper for another.
Salsa is preserved by adding acid, in the form of commercially bottled vinegar, lemon juice or lime juice. Use only vinegar that is at least 5 percent acidity and only bottled lemon or lime juice (never fresh squeezed). You must add acid to canned salsas and the amounts of vinegar or lemon juice in the recipes can not be reduced for safe boiling water canning.
Here is a salsa recipe from the UW-Extension Canning Salsa Safely bulletin. The recipe I use is:
Tomato/Tomato Paste Salsa
3 qts. slicing tomatoes, peeled, cored, and chopped
3 cups onions, chopped (3 medium whole)
6 jalapeno peppers, seeded and finely chopped
4 long green chilies, peeled, seeded, and chopped
4 cloves garlic, finely chopped
1 12-ounce can tomato paste
2 cups bottled lemon or lime juice
1 tbsp. salt
1 tbsp. sugar
1 tbsp. ground cumin (optional)
2 tbsp. oregano leaves (optional)
1 tsp. black pepper
Yield: 7 to 9 pints
Jalapeno peppers do not need to be peeled. Peel adn prepare chili peppers as described on page 3, if desired. To peel tomatoes, dip in boiling water for 30 to 60 seconds or until skins split, then dip in cold water and remove skins. Core and chop tomatoes.
Combime all ingredients in a large saucepan and heat, stirring frequently, until mixture boils. reduce heat and simmer for 30 minutes, stirring occasionally. Ladle hot salsa into clean, hot pint jars, leaving 1/2-inch headspace. remove air bubbles and adjust headspace if neeed. Wipre jar rims and cap with properly pre-treated lids. Process in a boiling water canner.
Process time in a boiling watyer canner for hot pack pint jars at the following elevations:
0 - 1,000 feet 15 minutes
1,001 - 6,000 feet 20 minutes
(Salsa recipes are available in Spanish from the National center for Home Food Preservation.)
www.uga.edu/nchfp/how/can_salsa.html