Originally Posted by oregonhophead
I have a Harpoon IPA clone recipe that I have had repeated success with but it's an extract recipe and I'm trying ag more often than not. The recipe is "partial grain" calling for 8oz 60L crystal, 4oz 2-row pale, and 1 0z roasted barley for steeping. Then 4lb pale malt syrup and 4lb light DME. I don't know of any exact formula for conversion to all grain. Thanks for any help.
There isn't an exact formula. Roughly you will need a third more grain by weight than extract. However, because extracts have different fermentability and extract potential of grain varies as does brewhouse efficiency from brewer to brewer you will have to approximate and then adjust accordingly in future batches. About 12 lbs of pale malt and 3/4 lb of crystal should get you into the general area of OG and color. IMO lose the roasted barley, it seems out of place in a Harpoon IPA.