I brewed an all grain s’mores stout, about 9% when I transferred to the secondary. Problem is it is very bitter from the unsweetened cocoa powder I used. Can I add some additional lactose post fermentation to get some sweetness?
I added 3 oz of pure vanilla extract when transferring, and did a lb or lactose 10 min before flame out
I figure if I boil it in about a half gallon I would lose some ABV, but would at least be adding sterile liquid.
The bitterness could be from other things, such as hops of course… But also, 3 oz of vanilla is too much IMO and can add bitterness in high amounts in my experience.
I would not add more than 1 lb lactose in 5 gallons, total. You might already be there.
Perhaps just give the brew more time to mellow. Maybe needs 4-6 months or more.
I have experienced the same situation where my beer into the secondary tasted harsh. My solution was to add lactose as you intend to do and it worked. However, I only added 8 ounces. And, like one of the other brewers mentioned, it will mellow in time.