Mass-produced fruitcakes made with mediocre ingredients fully deserve the derision they receive, but a good fruitcake can be truly wondrous when it's aged properly. When done correctly, it's as dense in rich flavor as it is in texture, yielding layers of subtle and complex notes from its fruit and spices. The cake needs at least three to four weeks to "ripen" after it's baked to give those flavors opportunity to meld. Serious enthusiasts preserve a fruitcake for years or even decades, while it grows in complexity and sophistication the whole time.
To ripen a fruitcake for a few weeks before the holidays, brush it with a moistening ingredient such as a light sugar syrup, fruit juice, or the traditional rum or brandy. Wrap it with cheesecloth followed by airtight plastic wrap, and refrigerate the cake for three to six weeks. Alternatively, roll a sheet of marzipan and seal your cake with the almond-flavored confection. Sealed in a bag or snap-top container, marzipan will also keep your fruitcake fresh-tasting for several weeks.
After a few weeks' curing, fruitcakes can be frozen to extend their shelf life. As long as they're adequately wrapped -- an airtight layer of plastic wrap and a foil or freezer-paper over-wrap is ideal -- the cakes will retain their quality for a year or longer. For traditional long-term storage, brush the cake with as much rum or brandy as it can absorb every week or two for up to six months; then keep the cake sealed in an airtight tin for up to two years. To age the cake over decades, line the bottom of a slightly larger tin with confectioner's sugar. Nestle the cake into your sugar; bury it in more sugar, and seal the tin.