( QUARTS PER LB * LBS GRAIN ) / 4 = GALLONS MASH WATER
GALLONS MASH WATER + (.09 * LBS GRAIN ) = VOLUME IN MASH TUN
PREBOL VOLUME + ( LBS GRAIN * %ABSORBTION ) = TOTAL WATER
(%ABSORBTION I USE IS 0.13 )
TOTAL WATER - [ ( QUARTS PER LB * LBS GRAIN ) / 4 ] = SPARGE
VOLUME OF GRAINS AND ABSORBED WATER AFTER DRAINING MASH TUN
LBS OF GRAIN ( .09 * ABSORB%) = VOLLUME OF WET GRAIN
I USE THIS TO DETERMINE HOW MUCH ROOM I HAVE FOR BATCH SPARGE ADDITIONS This will vary somewhat depending on kernel size, crush, etc. But it should be a decent starting point. Once you've drained your first runnings, it will over-estimate because of the soluble extract you've removed.