Step 1

Simmer: Bring 1 cup filtered water to a simmer, then stir in 1 cup white sugar. Continue to simmer for 3 minutes while stirring to dissolve the sugar, then remove from the heat and pour into a glass container.

Step 2

Steep: While the liquid is still hot, add the dried butterfly pea flowers to the water. Allow to steep for about 5 minutes, until the water is a vivid cerulean blue. Don’t wait too long, or the liquid will turn opaque. (Using the glass container from step one will allow you to gauge the color). You now have butterfly pea syrup!

Step 3

Juice: While the butterfly pea syrup is steeping, juice the lemons. You will need 1 cup of fresh juice.

Step 4

Strain: Once you are pleased with its color, strain butterfly pea syrup through a fine mesh sieve into a second glass container.

Step 5

Layer: Divide the ice between 4 glasses. Add ¼ cup butterfly pea syrup to each glass. Slowly pour 2 T of lemon juice into each glass. Stir the syrup and juice together if you want this entire layer to be purple, or pick up the glass and very gently swirl the liquid if you want a color gradient from blue to purple. Mix the remaining 1/2 cup lemon juice with the 4 cups of soda water.

Step 6

Finish: Using one hand, place a spoon upside down inside of a glass. You’ll want it to be near, but not touching, the syrup. Using the other hand, slowly pour 1 cup of the lemon-soda water over the spoon and into the glass. You should now have a color gradient from blue to purple to white! Repeat with the remaining 3 drinks.

Step 7

Serve: Serve the drinks as is in order to preserve the purple and white contrast, but have your guests to stir the mixture together before drinking to evenly distribute the sweetness.