Note from Ricardo This recipe is a simple ratio: for each citrus fruit, add 3 tbsp sugar to the same volume of citrus juice. This syrup can be made with other citrus fruits besides those listed above but keep their size in mind. For a large fruit (such as grapefruit), double the quantity of sugar and juice. This recipe makes use of citrus that’s no longer fresh. The concentrated syrup can be used to flavour cocktails, fruit salad or yogurt.