Nostrildamus
Well-Known Member
Is a high first runnings gravity but a low overall efficiency the sign of a poor crush?
I have failed to achieve anything over 65% with my false bottomed keg MLT. I do conversion checks with Iodine, hit and hold my mash temps, stir my mash on a regular basis, calibrate my thermometers and hydrometers on a regular basis, lauter extremely slow during my fly sparge, use hot sparge water and take regular gravity readings during my lautering, use a sparge arm, avoid channeling and maintain a nice level above my grain bed but I can't seem to break the 70% mark.
On my last brew I took three gravity readings before I boiled. The first runnings reading which was taken within the first gallon was 1.083. The second was at 7.5 gallons and was 1.050. The last was at 13 gallons and was 1.010. Using the beer recipator I rechecked after all was said and done and sure enough hit 65% just like I always do but one thing didn't add up to my brew buddy and I. It coughs out a figure stating that my estimated first run off should be 1.067 if my efficiency is as low as it is but my initial runoff was much higher (1.083). I bumped the efficiency field up until I met that figure and it indicated I would be running at 80% efficiency. Granted, these are only estimates and every system is different.
It did however suggest something to me. Is it possible that I have an inefficient crush which when mashed in an efficient tun at a proper temperature leads to a really decent conversion and concentration of sugars but which renders poor access to the entire volume of sugar held in the grain? It almost seems to me like my MLT and mash are chewing through the sugar and working really well but then as the sparge starts run out of available sugar too early.
Next batch I will probably grind myself with a friend's mill and hopefully I'll get better results.
I have failed to achieve anything over 65% with my false bottomed keg MLT. I do conversion checks with Iodine, hit and hold my mash temps, stir my mash on a regular basis, calibrate my thermometers and hydrometers on a regular basis, lauter extremely slow during my fly sparge, use hot sparge water and take regular gravity readings during my lautering, use a sparge arm, avoid channeling and maintain a nice level above my grain bed but I can't seem to break the 70% mark.
On my last brew I took three gravity readings before I boiled. The first runnings reading which was taken within the first gallon was 1.083. The second was at 7.5 gallons and was 1.050. The last was at 13 gallons and was 1.010. Using the beer recipator I rechecked after all was said and done and sure enough hit 65% just like I always do but one thing didn't add up to my brew buddy and I. It coughs out a figure stating that my estimated first run off should be 1.067 if my efficiency is as low as it is but my initial runoff was much higher (1.083). I bumped the efficiency field up until I met that figure and it indicated I would be running at 80% efficiency. Granted, these are only estimates and every system is different.
It did however suggest something to me. Is it possible that I have an inefficient crush which when mashed in an efficient tun at a proper temperature leads to a really decent conversion and concentration of sugars but which renders poor access to the entire volume of sugar held in the grain? It almost seems to me like my MLT and mash are chewing through the sugar and working really well but then as the sparge starts run out of available sugar too early.
Next batch I will probably grind myself with a friend's mill and hopefully I'll get better results.