1 cup water, plus more to fill the bottle
3/4 cup granulated sugar
1 1/2 tablespoons fresh lavender flowers or 1 tablespoon dried
1 lb. very ripe white peaches
1 Tbsp. lemon juice
1/4 tsp. champagne yeast or baker's yeast
Tools: one clean 1-liter plastic soda bottle with screw-on cap, saucepan, food processor, cheesecloth
Bring the water to a boil in a small saucepan on the stovetop or in the microwave. Remove from heat and add the sugar and lavender flowers. Stir to dissolve to sugar. Let stand for 20 minutes to infuse the sugar water with lavender.
Wash and roughly chop the peaches. It is not necessary to peel them. Strain out the lavender flowers and pour the infused sugar water over the fruit. Add the lemon juice and salt, and stir to combine. Let this stand for 10 minutes to macerate the fruit.
Working in batches, purée the peaches with the sugar-water in the food processor or blender. Strain the purée into a bowl, collecting as much juice as possible without forcing any solids through the strainer. You can also strain the juice through a flour sack towel or cheesecloth to yield a cleaner soda. You should end up with 1 1/2 to 2 cups concentrated fruit syrup.
At this point, you could stop, refrigerate the syrup, and add it to a glass of sparkling water to taste. To naturally carbonate the soda with yeast, read on.
Pour the juice into a clean 1-liter plastic soda bottle using a funnel. Top off the bottle with water, leaving about an inch and a half of head room. Give it a taste and add more lemon juice or sugar if desired. The extra sugar will dissolve on its own.
Add the yeast. Screw on the cap and shake the bottle to dissolve and distribute the yeast. Let the bottle sit at room temperature out of direct sunlight for 12 to 48 hours. Check the bottle periodically; when it feels rock-solid with very little give, it's ready.
Refrigerate overnight or for up to 2 weeks. Open very slowly over a sink to release the pressure gradually and avoid bubble-ups.
Emma Elizabeth Christensen, EmmaElizabethChristensen.blogspot.com