Adding Distilled Spirits at the end of a fermentation

Local Festival is having a beer making contest. One of the requirements is the addition of a distilled spirit. Is it best to add it with the priming sugar right before bottling? Or should I consider adding it while it's in the secondary fermenter/carboy?

Fortified beer contest? Boilermaker Brews? Interesting and unusual.

Just fortifying a beer can lead to thin body and sometimes harsh alcohol from the infusion. I'd add depth by adding ingredients with parallel flavors during secondary and adding the spirit at the end.

For instance, if you were choosing gin, then I'd add botanicals to the secondary. If it was whiskey, I might add whiskey soaked Oak chips and perhaps a vanilla bean or two. Maybe even some smoked malt to the grist. Vanilla, raw sugar (or a touch of molasses) and maybe toffee for a rum infusion.

It's a beer contest for the Whiskey Rebellion Festival. So, it needs 15-30% rye, 5-15% corn, be brewed to between 6-8%, and a distilled spirit added. I'm trying for a more traditional mix closer to a 1790s style english ale, using older hops, and even a bit of botanicals. My plan is to use a white whiskey, probably a wheat or rye.

Once in a while I like to add a little J.D. bourbon to the glass before filling it up with brown ale, makes for nice flavour.