Place the currants in a medium-size bowl, and pour the wine over them.
Stir to distribute the wine.
Cover the bowl and put in a warm place for 2 hours so the currants plump up and absorb some of the wine.
Place a rack in the center of the oven, and preheat the oven to 250°F.
Generously grease and flour a 101/2″ × 5½” × 3″ loaf pan.
Shake out the excess flour, and set the pan aside.
Drain the currants well, reserving the wine.
You should have about 3 ounces of wine.
Set it and the currants aside.
Place the sugar and butter in a large bowl, and beat with an electric mixer on medium-high speed until light and fluffy, 3 to 4 minutes.
Add the eggs, one at a time, beating well after each addition.
Scrape down the sides of the bowl with a rubber spatula.
Sift the flour, salt, cinnamon, nutmeg, and mace into a medium-size bowl.
Alternately add the flour mixture and the wine to the batter, beginning and ending with the flour mixture, beating on low speed until just combined.
Fold in the currants until well distributed.
Turn the batter into the prepared pan, and place the pan in the oven.
Bake the cake until a toothpick inserted in the center comes out clean, 2¼ to 2½ hours.
Place the pan on a wire rack to cool for 15 minutes.
Run a knife around the edges of the pan, gently shake the pan to loosen the cake, and invert the cake once and then again so the cake cools right side up on the rack for at least 30 minutes before slicing.
The cake will slice better after it is completely cooled, 2 hours.
Store as you would a fruitcake, wrapped in cheesecloth in a tightly sealed tin or wrapped in plastic.
