My first all grain i did S&A IPA ----> http://www.homebrewtalk.com/f69/s-ipa-118158/
per the original recipe:
mash at 150 for 90 minutes
strike water = 13.65 lbs x 1.5 qts/lb = 5.12 gallons for mash
grain absorption = 5.12-(13.65 x .125 gallons/lb)= 3.41 gallons from mash.
i sparged with about 4 gallons of 175 degree water and mixed
strike water temp = (.2/1.5)(150-66) + 150 = 161.2 ~162
so i heated the water to 162 and poured in grains. i hit about 156 degrees, so i mashed at 156 for 90 minutes....i finished around 148.
i collected just over 7 gallons of wort. i could have drained the grain bag more but my arm got tired lol.
boiled down to just over 5 gallons, probably 5.25 gallons i estimate.
my starting gravity before boil was 1.052
my OG after boils was 1.066 (temp adjusted) im only .05 points off.
how do i calculate efficiency? im guessing i did good.
the mash: 13 lbs of grain
lots of yummy hops