Simply combining flavored syrup with seltzer or club soda makes homemade soda. Depending on how sweet you prefer it, change the ratio
No.1 Rhubarb Soda
Over medium heat, simmer 3 cups chopped rhubarb with 1 1/2 cups water and 1 cup sugar for 15 to 20 minutes or until the mixture is broken down and sticky. Let the mixture cool fully before pressing the particles through a cheesecloth-lined sieve. Add to seltzer.
No.2 Blackberry-Lime Soda
Simmer 1 cup water, 3/4 cup sugar and 1 pint blackberries over medium heat until syrupy, 15 to 20 minutes; strain, pressing on the solids. Stir in the juice of 1 lime. Let cool completely. Mix with seltzer
No. 3 Lemon-Lime Soda
1 cup of sugar and water should be simmered until the sugar dissolves. Add 1/2 cup of each lime and lemon juice. Add to seltzer (per drink, use 1/2 cup syrup).
No.4 Apricot-Ginger Soda
Simmer Over medium heat, combine 2 cups apricot nectar, 1 cup peeled, thinly sliced ginger, and 3/4 cup sugar. Cook until syrupy, about 15 to 20 minutes; drain. Allow to totally cool. Blend in seltzer.