Add 2 teaspoons coffee essence to the custard in the Custard-Based Ice-Cream, before folding in the cream. Alternatively, add 2 ounces coffee beans to half the cream in the Mousse-Based Ice-Cream. Infuse the cream slowly over very low heat for 45 minutes (the cream must not come to the boil). Pour the cream mixture through a fine strainer into a bowl and discard the coffee beans. Allow it to cool, beat in the remaining cream and proceed with the recipe.