8 cups rhubarb, coarsely chopped
8 cups water
3 cups sugar
1/2 cup lemon juice
1 small package strawberry jelly powder
Bring rhubarb, water and lemon juice to a boil and simmer 15-20 minutes until rhubarb is mushy. Strain through cheesecloth or jelly bag. Discard/compost pulp (or use it in yogurt). Return juice to heat and add sugar and jelly powder. Cool to room temperature. Transfer juice to a large container (an ice cream pail works well) or roasting pan and place in the freezer. Stir frequently while it's freezing to keep the mixture slushy. Store in freezer.
Use an ice cream scoop and fill a glass about 3/4 full of slush. Top with 1 1/2 oz vodka (optional), then fill the glass with soda water or ginger ale. Slip in a straw and sip!