Has anyone ever used maple extract in bottling bucket? I'm wondering how much to use for a subtle maple taste in two gallons on chocolate oatmeal stout?
I've not used that one, but I've used raspberry extract. In my case I use half the bottle in a 5-gallon batch and it gives just the right hint of raspberry flavoring without over-powering the beer. I think the bottle is 4 ounces. So if 2 ounces is good for 5 gallons, then in your case 0.8 ounces would be a good starting place for your maple extract in a 2 gallon batch.
I've tried this (once) and would not recommend it.
I added 20 ml of pure maple extract to 5 gallons. Maple flavor was present, not overwhelming. BUT it gave a strange metallic taste to the beer, so it was drinkable but not very good.
Order grade B maple syrup from a maple syrup farm on line---3 cups added to 5 gallons gives a much better maple flavor than the extract.