Liqueur Grapefruit Castro. The Grapefruit Castro liqueur is produced from 100% natural grapefruit peel extracts, in a traditional way. It is a bitter-sweet intense and explosive liqueur. The grapefruit peels release juicy and succulent aromas into the alcohol, while the sugar blends the mixture, producing sweet and bitter notes that are perfectly balanced. It is recommended before or after meals, straight, on the rocks, combined with Tentoura Castro, Mastiha Castro or Vanilla Castro liqueurs, or with aged distilled spirits, such as Brandy Castro, with fresh lemon, lime or pineapple juice, with grenadine syrup, or in cocktails.