Following my post on thick salsa made from baked sliced tomatoes, a reader asked about making fermented salsa. I grimaced as I considered how easily tomatoes rot. Cutting them up and leaving them to ferment would be asking for trouble, I figured. But I do sometimes brine tomatoes whole, in the Russian tradition. So I suggested fermenting whole tomatoes with other vegetables and then grinding them all together afterward.
In early October, Mother Nature had spared us the usual late-summer to early-fall rains but hit us with early frosts instead. So my entry hall was filled with boxes of tomatoes, all still beautifully free of disease. I had so many tomatoes and peppers both that if a crockful rotted I’d never miss them. In particular, I had plenty of Hard Rock tomatoes, one of my favorite paste varieties. So I came up with this recipe for—
Fermented Tomato Salsa
3 pounds flawless, firm, meaty tomatoes, ripe or semiripe, washed but left whole
1 pound green jalapeño peppers, tops sliced off
1 ½-pound onion, peeled and quartered
6 garlic cloves, peeled
2 teaspoons cumin seeds
¼ cup lime juice
5 tablespoons pickling salt
2 quarts water
Mix the tomatoes, peppers, and onion pieces together in a gallon crock or jar. Add the lime juice. In another container, dissolve the salt in the water. Pour the brine over the vegetables, and weight them. Cover the crock or jar, and keep it at room temperature for at least a few days, after which you can move it to a cooler place if you prefer. Check the crock or jar for yeast and mold and skim off any that appears.
After three weeks, cut a pepper vertically to be sure it has completely changed color. If it has, gently remove all the vegetables to a bowl, taking care not to burst the tomatoes, which will have swelled. Coarsely grind the vegetables in batches in a food processor or blender. You should have about 7 cups salsa.
My fermented salsa had a good, thick consistency, a pleasantly dark red color, a mild tartness, and a complex fermented taste that grew on Robert and me so fast that we ate a whole pint at a sitting. The only thing that could have improved the experience is fresh cilantro.
I tested the pH of the salsa as 4.3—low enough for safe boiling-water processing, but high enough that I’d advise testing each batch or adding more lime juice before canning. I brought the salsa we hadn’t eaten slowly to a boil and then processed the jars for 15 minutes.
If you want those fermentative bacteria to work in your gut, of course, you will store the salsa in the refrigerator instead. If you do, please let me know how long it keeps.