Combine the ginger ale, honey, vanilla, and brown sugar in a large pot over medium heat.

Peel the skin from the oranges and lemons, leaving all the pith (the bitter white part) on the fruit, and add the skins to the pot.

Slice the pith from the oranges and lemons. Quarter the oranges and lemons and remove any seeds. Squeeze the juice into the pot and toss in the chunks of fruit.

Add the raisins, cinnamon sticks, caraway seeds, cloves, peppercorns, and allspice.

Reduce the heat to a simmer and stir occasionally for 30 minutes.

Remove the pot from the heat, strain the liquid into another large pot through a collander to remove the large chunks.

Strain again through a mesh strainer to remove the pulp and any remaining seeds. Let it cool for a few minutes.

Add the whiskey to the pot and stir to combine.

Pour into bottles or mason jars and refrigerate until used. Warm gently before serving.