Bright and fruity with a caramelized depth of flavor thanks to brown sugar and a four-day ferment, this homemade lemon soda is enjoyed during the May Day celebration in Finland. Pair it with tippaleipa (Finnish funnel cakes) for an authentic treat.
- 1⁄8 tsp. fresh yeast
- 3 cups filtered water
- 1⁄2 cup packed dark brown sugar
- 3 tbsp. fresh lemon juice
- 1 tsp. granulated sugar
- 5 golden raisins
Mix yeast and ¼ cup filtered water heated to 115°; let sit until foamy, about 10 minutes. Place brown sugar in another bowl. Bring 1 ¼ cups water to a boil in a 1-qt. saucepan; pour over sugar and stir until sugar is dissolved. Stir in remaining water, lemon juice, and granulated sugar; let cool. Stir in yeast mixture and drape a clean dish towel over bowl; let sit at room temperature (ideally 70-75°) for 24 hours.
Using a funnel, pour soda into a sterilized 1-liter plastic soda bottle, filling to within 1" of the top or lower. Add raisins and close bottle tightly with top. Let sit at room temperature (ideally 70°-75°) for 24 hours (the bottle should become rock-hard with the pressure that builds up within). Refrigerate soda for 2 days before opening and serving. Drink soda within 1 week of opening, and store in the refrigerator.