
Watermelon liqueur is a sweet fruit liqueur flavored to taste of ripe watermelon.
Mix 2 parts vodka, 2 parts fresh watermelon juice, and 1 part watermelon syrup. That matches the strength and sugar, with a fresher flavor.
Alone it leaves the drink weaker and less sweet.
At the same amount it adds a little sweetness and turns the drink bright green.
Watermelon flavor fades fast once the bottle is open. Plan to finish it within six months.