This recipe is one of a few different ones from the US Department of Agricutlure's Complete Book On Canning. It's a winner in our book! The sweetness only depends on how sweet your tomatoes are, and the spiciness totally depends on how mature the jalapenos are. If they are pretty spicy then you will end up with about a medium to medium hot salsa.
10 cups peeled, chopped tomatoes
6 cups chopped chili/mild peppers*
4 cups chopped onions
1 cup vinegar
3 teaspoons salt
½ teaspoon pepper
Directions:
Combine ingredients in a large saucepan. Heat to a boil and simmer 10 minutes. Ladle hot into pint jars, leaving ½ inch headspace. Adjust lids and process in a boiling water canner: 15 minutes at 0-1,000 feet altitude, 20 minutes at 1,001-6,000 feet; 25 minutes above 6,000 feet.
* We used 3 1/2 cups jalapenos and 2 1/2 cups bell peppers. You can remove the seeds from the peppers to make it milder.
More info...
We like our salsa thick, so we boil it until we're happy with the consistency, which is a lot longer than 10 minutes. Our last batch took almost 2 hours! Just remember to stir often it or it will scald.
Also, don’t change the ratio of vegetables to acid and tomatoes. You can only change the amount of salt, pepper or switch the vinegar to bottled lemon juice. I wouldn’t recommend changing the vinegar to lemon in this salsa though.