Spring Elixir Soda

• 8 ounces rhubarb, cut into half-inch slices
• 1 1/2 cups water
• 2/3 cup freshly squeezed lemon juice, divided (about 3 large lemons)
• 12 ounces granulated sugar
• 3 to 4 cardamom pods, crushed
• 1/4 to 1/2 teaspoon rose water
• seltzer water (or dry bubbly wine)

1. Combine the rhubarb, water, and half of the lemon juice in a medium saucepan, and bring to a simmer over medium-high heat. Reduce heat to maintain a simmer, and cook until the rhubarb is very soft and starts to disintegrate.
2. Strain the rhubarb mixture through a fine mesh strainer lined with 2 layers of damp cheesecloth. Press on the solids with a spoon to extract as much liquid as possible. Discard the solids and rinse out the sauce pan.
3. Return the rhubarb water to the saucepan, then add the sugar and cardamom pods. Bring to a boil over medium-high heat, gently swirling the pan on occasion. Allow to boil for several minutes to infuse with the cardamon flavor and slightly reduce the mixture.
4. Remove from the heat and add ~3/4 of the remaining lemon juice. Taste for tartness and cardamom flavor. Add more lemon juice if desired. Strain the cardamom pods out, or allow to steep for several minutes before straining. (note: you may want to dilute a small amount of the syrup with water when taste-testing). Allow the mixture to cool, then stir in 1/4 teaspoon rose water. Taste and add more rosewater by the 1/8th teaspoon as desired. The rhubarb flavor should predominate, with just a whisper of rose and cardamom.
5. Transfer to a sealable container and store in the fridge. Combine syrup with seltzer to you desired strength. A good starting point is 2 tablespoons with a cup of seltzer (a 1:8 dilution).

rhubarb, water, freshly squeezed lemon juice, sugar, cardamom pods, water, water

Taken from food52.com/recipes/35080-spring-elixir-soda (may not work)