I have a quick question regarding following someone else's recipe.
When you see a recipe posted, quite often I find that there's no indication of the efficiency of extraction for the poster, nor an indication of the SG of the beer.
So my question is, how do you follow someones recipe, when you have no idea what you're actually shooting for in terms of the SG.
eg. Tom posts a recipe for 14lbs 2-row (100% efficiency in 8 gallon mash = 14*37/8 = 65points or 1.065 SG). Lets say Tom has an extraction efficiency of 80% (52pts or 1.052 SG). However, I want to copy this recipe from Tom, but my home efficiency is only 60% (39pts or 1.039). Therefore, if I copied the recipe verbatim, I would be well off on the SG, and subsequently ABV since I have significantly lower efficiency in my setup than Tom does. To get the same starting gravity, I would have to use much more base malt (~4lbs more).
So my question is, how do you copy someones recipe when you have no knowledge of their efficiency or the SG. Do you assume an efficiency (say 75%) and go on that?
I am new to brewing, so please forgive the ignorance of this question.