cloning and doing the math

[nathanm]

I recently got a recipe out of one of my favorite small breweries. I did good. I initially got the "we'd have to kill you" if they gave out the recipe, so I just murmured a few things about 2-row and some crystal (for a hoppy pale ale) and a few other leading questions and perhaps, unbeknown to him, he suddenly came forth with hops (though no schedule, but which hop was first wort hopped etc) and actually gave me the grain quantities and yeast. Sweet! He seemed genuinely happy that i was so interested in this recipe and the leading questions definitely helped.

So here is my question, the brewery does 14 barrel batches and I gather that 1 barrel is 31 US gallons. So lets say that the amount of 2-row they use is 750lbs per batch. I normally always do my batches to have 6.5 gallons at the beginning of the boil and 5.5 at the end, for 60-70 minute boils. Do i use the 6.5 or 5.5 to figure out how many lbs of 2-row to use? Perhaps this is a stupid question but I can't do math right now......

[BDawg]

I'd use the 5.5, but remember that he's probably got efficiencies up in the high 80's to low 90's, while you are probably sitting around 75%.

What you really want to find out is his OG and his IBUs, then keep the ratios of grains the same as his with respect to each other (ie, same percentages), but adjust the total amount to hit the same OG given your 5.5 target and your normal efficiency.

Then, do the same thing for the hops. Remember also that he probably gets better hop exaction than you will, too due to the larger boil, so adjust your flavor and aroma additions up a little bit to compensate. Then finally go back and add enough bittering/FWH hops so that the IBUs reach the target IBU level.

HTH-