I have a brown thumb. I kill houseplants with 100% effectiveness. So I was thrilled when I was able to cultivate kombucha. Granted, it doesn’t need to be watered, or really tended in any way, but just the fact that I could take a half bottle of store-bought liquid and turn it into a thick, slimy culture that covered the whole surface of my bowl-full-of-tea seemed like a microbiological miracle. Once my kombucha took off, there was no stopping me. I became a fermentation fiend. Jars and bottles covered every available surface. Yogurt, kefir, cheese, kimchi, sour pickles, apple cider vinegar, even lacto-fermented root and ginger beer. Time and again I was delighted by the magical transformation of raw materials into something richer and…