Sugar does not affect the pH of the foods directly, just the taste. So it tastes sweeter.

Adding the sugar poses so safety concerns.

Dave

PS: Recipe doesn't ring a bell. What was the source of the recipe? That is a lot of cups of tomatoes and onions for only 1 cup of acid.

It's a recipe I got from this site, but I don't know who to attribute it to. Here's the recipe I cut and pasted, with my addition of the sugar.

SALSA VERDE
7 Cups chopped, cored, green Tomatoes
5 to 10 Jalapeno Peppers, seeded and finely chopped
2 Cups finely chopped Red Onions
4 Cloves Garlic, finely chopped
ü Cup Sugar
1/2 Cup Lime Juice
1/2 Cup loosely packed finely chopped Cilantro
2 Teaspoon ground Cumin, more to taste
2 Teaspoon dried Oregano
2 Tablespoons Salt
1 Teaspoon freshly ground Black Pepper
In a large stainless steel saucepan, combine tomatoes, peppers, onions, garlic and lime juice. Bring to a boil over medium-high heat, stirring constantly. Stir in cilantro, cumin, oregano, salt, sugar and black pepper. Reduce heat and simmer, stirring frequently, for 5 minutes. Remove from heat. Ladle hot salsa into hot jars, leaving 1/2 inch headspace. Remove air bubbles and adjust headspace, if necessary, by adding hot salsa. Process both sizes in a BWB for 20 minutes.
Makes about six 8-oz jars or 3 pint jars

Obviously I doubled the recipe to accommodate the amount of tomatoes I had to use. As I said, it's quite good, just a little sour for my taste.

Steve

I just did a quick search and found the original recipe posted by jcpyburn on Sept. 29, 2009. She indicates it is from the Ball Complete book, and says it is "very safe and very delicious".

Steve

I think the confusion arose in part because the recipe calls for green tomatoes which are a good deal more acid than the tomatoes mentioned in the original post.

In this case the word green is a significant distinction.

Carol

Yes, green tomatoes are more acidic than ripe ones but they aren't 2x as acidic and that is double the cups of tomatoes per cup of acid than one usually sees. Thus my question about the source. ;)

It is always vary helpful to us if the source of a recipe is included in the post.

Since it is a Ball Complete Book recipe then yes, it is a tested and approved one. But if it had come from some place like cookingusa.com or from some unknown source then I would be much less inclined to trust its safety.

Dave

Sugar is NOT a preservative unless in concentrations of over 50 % or more, as in a regular sugar jam/jelly. Otherwise it is only for flavor and makes no difference in ph levels.