I love sima! I included a recipe for it in my book so I've made many, many batches and a whole lot of variations. I like to just refer to it as fermented lemonade. I make it with lemons, sugar and champagne yeast. You can also riff by adding other fruits, like strawberries or raspberries or blueberries, or herbs or spices (lemon & lavender are killer together). Or by making it with other citrus fruits - there are a TON of variations. I've served it at many public events and the keg always kicks fast, especially in the summer. It was originally made with honey and bread yeast or other native yeast (meaning not intentionally innoculated) but it's commonly made with sugar and commercial yeast these days (bread or other). Raisins were originally used in this & many other beverages (kvass, off the top of my head) - they would sink initially & float once fermentation/carbonation occurred - kind of a natural indicator of when it was ready (no hydrometers or PET bottles in the old days, right?). I usually keg my sima but use plastic if I'm doing batches less than 1.75 G (the size of my smallest kegs). It's a super easy & darn tasty beverage, especially for warmer months.