How do I add citric acid to my hard candy without it burning? Every time I try a recipe and add the flavoring and citric, within seconds the citric burns and gives the candy a horrible taste. How or when should I add it so that this won't happen. I'm using a powdered form of the citric acid.
Colors and flavors, including acid, are added after the candy is taken off the heat.

The syrup is still blisteringly hot (literally) but I've never had powdered acid burn in it off the stove.

If your acid is actually burning in the hot syrup then I would recommend finding a new source.