Rhubarb Juice with Beet Spheres
For the Beet Spheres:
In medium saucepan, bring beet juice, 50 grams water, 50 grams sugar, and calcium lactate to a boil. Remove from heat; then strain through coffee filter. Cover and refrigerate to chill. Pour beet liquid into 10 hemispheric molds each 1 inch (2.5 cm) in diameter. (These are fragile, so making a couple extra ensures you will have enough to plate.) Freeze. Reserve remaining beet liquid for later use. To make sodium alginate bath, mix together 50 grams sugar, sodium alginate, and 1000 grams water in medium saucepan. Warm to dissolve sugar and sodium alginate. Strain through chinois into deep container. Disperse frozen spheres evenly in warm sodium alginate bath, taking care they do not touch one another. As spheres thaw, they will form a thin membrane that will encapsulate the liquid center. Fill 2 stainless-steel bowls with hot tap water. When spheres have encapsulated, remove with slotted spoon and drop into one bowl of hot water. Stir gently to rinse. Repeat rinsing in second bowl. Transfer spheres to reserved beet liquid and refrigerate.
For the Rhubarb Juice:
In small saucepan, slowly heat rhubarb juice, citric acid, and sugar until mixture separates. Skim away foam. Strain through coffee filter and set aside.
To Assemble and Serve:
Serve rhubarb juice in a small shot glass, with one beet sphere floating in it.