Just as soon as we finish a batch of cultured salsa I start another one fermenting. The introduction/nurturing of lactobacillus bacteria gives the salsa probiotic qualities and greatly increases its refrigerator life. Normally a salsa made from fresh ingredients won’t keep in the refrigerator for more than a few days to a week, especially if it is made with cilantro. A fermented salsa stays crunchy and fresh for several weeks, even with cilantro.
I start by placing the jar in which I will make and store the salsa on a kitchen scale and set the dial at zero. Then I go about cutting up the vegetable ingredients. It takes a lot more time but I like to chop everything by hand. The ingredients for today’s salsa were:
- serrano chilis
- Fresno chilis
- tomatoes (including the juices)
- sea salt or kosher salt
- yogurt whey
When the jar is full of chopped ingredients I weigh the full jar. The amount of sea salt I add is 1.5% of the weight of the vegetables. In the past I used a ratio of 2% but the result was a very salty salsa. At 1 1/2% it is still salty but tolerable. Friendly probiotic bacteria thrive in a salty environment, whereas undesirable harmful bacteria do not.
Lactobacillus bacteria occur naturally on the skins of vegetables and will develop on their own in a saline environment. Adding yogurt whey ensures that friendly bacteria are present and hastens the fermentation process. The fluid from the vegetables and the whey should come to the same level or, better still, cover the vegetables. The salt usually draws out plenty of liquid. The vegetables can be pressed down in the jar if need be to extract more fluid.
I leave the salsa at room temperature for 12 to 15 hours before storing it in the refrigerator. Fermentation will continue in the refrigerator but at a much slower pace. It probably isn’t necessary, but I like to place a paper towel between the lid and the jar during fermentation to allow it to breathe without the introduction of harmful bacteria. I remove the paper towel and screw the lid on tightly when it goes into the refrigerator.