Combine the wines in a large pot.
Using a vegetable peeler, zest the citrus fruits.
Tie up the lemon zest, orange zest, cloves, cardamom, cinnamon and ginger in cheesecloth and add to the wine.
Juice the lemon and orange. Add the juices to the wine, along with the raisins, almonds and sugar.
Bring wine mixture to a boil over medium-high heat. Reduce heat and gently simmer for 15 minutes, or until flavors are well blended and almonds are soft. Skim wine occasionally to remove any foam.
Just before serving, remove the cheesecloth and aromatics, and add the bitters and aquavit. Ladle the glögg into mugs and serve with a spoon for eating the raisins and almonds. Note: glögg can be stored in the fridge for up to a week and then reheated on the stove or served cold.