 titrated some ReaLemon made from concentrate and found that it tested at 4.9% citric acid, exceeding the federal standard of 4.5%. She also found a study that tested the acidity of lemons from Florida and California, and the range was 4.53% to 7.3%, all of them exceeding the standard. Then she titrated a supermarket lemon: 6.0% acidity. It looks like a fresh lemon will provide at the least the acid content of the bottled stuff, and even if one lemon or lime is below the standard it is very likely that by using several lemons or limes the average acidity will be greater than the standard. Given that one and a half tablespoons of bottled lemon juice brings a pint of salsa to a pH of about 4.2, even if a lemon or lime was a bit below the standard 4.5% acidity there’s enough margin of safety that it would have little effect.
I cut up two medium onions and sweated them at low heat in a pan coated with a little oil, long enough to remove the pungency and added them to the mix. Garlic, parsley, and oregano were chopped and added. For hot peppers I used one jalapeno and one serrano, deseeded, for each pint. I also threw in a tobasco for the batch.
Then there’s the acid component. I like the taste of lime in salsa. Two limes gave up 3 oz of juice. The batch produced six pints of salsa, so 3 oz works out to 1 tablespoon per pint, the amount recommended by the NDSU publication. Just to be on the safe side I added 1.5 oz of the bottled lemon concentrate, for 1.5 tablespoon per pint. Anyway that’s how I made the salsa. In a few days there will be enough tomatoes for another batch. This time I’ll buy more limes and use more serranos. (Those are refrigerator okra pickles next to the salsa).