I am using Nigella's recipe for my Christmas Plum cake. How long can i store the cake? Do I need to keep it refrigerated?
Plum cake appears to be the Indian version of a fruited Christmas cake so we assume that you are referring to Nigella's Traditional Christmas Cake or Time-Honoured Cristmas Cake (from Christmas and Feast respectively). Both of these cakes should keep fairly well and can be made 6 weeks in advance. If you are keeping the cake then wrap it tightly in a double layer of baking parchment, parchment paper, greaseproof paper or wax paper then a double layer of foil.
The cake needs to be stored in a cool, dry and dark place. If you live in a hot or humid environment then it may be better to either freeze the cake until you want to ice or serve it, or keep it in the fridge. The cake can be frozen for up to a year. The cake needs to thaw overnight at room temperature if it is frozen. If you are going to marzipan and then ice the cake then let the cake come up to room temperature before applying the marzipan and icing layers and don't refrigerate the cake again after adding the marzipan. If the cake is very cold the marzipan and icing can get beads of sugary condensation on their surfaces.
If you can't use alcohol in your cakes then you could use orange juice as an alternative. However this may reduce the keeping time of the cake as the alcohol helps to act as a preservative.