Grape soda should taste like real grapes, and not like purple syrup. You can use all-natural ingredients and still get a soda that's bold in both color and flavor. This recipe was inspired by one that appeared in Saveur.
Notes: You can juice Concord grapes for this recipe or buy 100% pure Concord grape juice. If you'd like to use sugar instead of agave nectar, use half as much by volume. If using an alternative sweetener such as stevia, consult the packaging to see how much to use, as it varies based on whether the sweetener is liquid, powdered, or mixed with other ingredients. Champagne yeast (also called Prise de Mousse) can be found in most brew shops. You can order it online from The Beverage People. A 10 gram vial is enough to make gallons of soda.
- 3 cups Concord grape juice (see note)
- 2 1/2 cups filtered water
- 1/2 cup light agave nectar
- 1 tablespoon zest from 1 lemon (preferably Meyer lemon)
- 1/8 teaspoon Champagne yeast
Combine grape juice, water, agave nectar, and lemon zest in a large pot and bring to a boil over medium heat. Reduce to a bare simmer and cook for 30 minutes, stirring occasionally.
Let the mixture cool to room temperature, then strain out the lemon zest. Add the yeast and cover the pot with a kitchen cloth. Let sit for 24 hours.
Pour the liquid into a clean plastic soda bottle, leaving 1 to 2 inches space at the top. Put the cap on tightly and let rest at room temperature for 24 hours.
Open the bottle to check the carbonation, being careful to release the gas slowly to avoid explosion or overflowing. If you are happy with the amount of carbonation, put the closed bottle in the refrigerator for 24 hours before serving. Otherwise, reseal bottle and allow to continue to ferment until desired carbonation level is achieved. Keep refrigerated for up to 2 weeks.
Pot, zester, fine-mesh strainer, funnel, plastic bottle with cap