Adding lactose after primary fermentation

hbarsquared

I brewed up a beautiful stout, but I went a little heavy on the roasted grains and it's more bitter than I'd like. I was thinking of adding some lactose to balance it out. Are there any issues I would run into adding it to the fermenter after it reached terminal gravity?
I'm planning on making a kind of simple syrup with it so I know it is sanitary.

hotbeer

Depending on how much you wish to add, you could use it with your priming sugar if you are intending to bottle.
Regardless, even though it's supposed to be unfermentable, you might re-start some fermentation and it might get cloudy as things get stirred up by the yeast. So just take that into account.