- Our Black Walnut Costa Rica Decaf coffee is a deliciously decaffeinated, all-naturally flavored, full-body Costa Rican coffee blended with Black Walnut Leaf, Walnuts and Rose Petals. You will enjoy tasting the elegant Black Walnut flavor and the decaffeinated, mildly acidic, premium Costa Rican coffee taste! - Ingredients: Decaffeinated Costa Rica coffee (whole coffee beans), Black Walnut Leaf, Walnuts, Rose Petals and Natural Black Walnut Flavor.