This may seem an excessive amount of sugar, however, this is not the usual fruit to sugar ratio which is used in jam making. For the marmalade we use a large amount of water to soak the fruit. The water is included in the marmalade so this means a larger amount of sugar. When making marmalade and jams, the sugar is not just a sweetener, it also assists with gelling and preservation. Therefore, I don’t recommend reducing the amount of sugar as it may interfere with the setting and preservation. The sugar is an important component in making the jam shelf-stable. Citrus fruits are high in pectin so it is not necessary to use jam sugar. Regular granulated sugar is all that is required.