Originally Posted by a10t2
Assuming the DME contributes about 43 point-gal/lb, and the grain is 37 point-gal/lb (since you'd always be replacing extract with base malt), it would be:
1 lb DME = 43/(37*E) lb malt, where E is the efficiency. At 75% efficiency, that's 1.55 lb.
good point...I just always assume 70% efficiency, which gets you 1.67lbs. If you know your brewhouse efficiency, obviously use that # instead.
As for which grains to use...color is only one consideration. Unless you know what grains went into the DME (which often you don't ), it will be hard to match. Using Vienna for color is fine, but it will likely give you a different flavor than the DME - I doubt the DME used Vienna (though I really have no idea)