Combine the water, white grape juice, guava syrup, passionfruit powder, and citric acid in a medium saucepan, then warm the mixture over low heat while whisking until dissolved. The base is ready when it looks smooth and evenly blended with no powdery bits floating around.

Stir the hot water and butterfly pea powder together in a small jar until the powder dissolves, then leave it to cool to room temperature. The infusion should look deep blue and clear enough to pour easily.

Add the popping boba to a tall glass, fill the glass with ice, then pour in ½ cup Tropical Butterfly Refresher Base and ½ cup water and stir gently. The drink should look cold and bright before you add the blue layer.

Slowly top the drink with the cooled butterfly pea infusion and serve with a boba straw. You’ll see the upper layer stay blue at first, then turn purple where it meets the acidic base.