by James L » Wednesday Sep 24, 2008 2:44 pm
Get combined readings to measure efficiency. make sure it is well mixed before taking the measurement. If you get a reading higher than what your beersmiths tells you for the effiency that you have given, you obviously have a better extraction efficiency that what you expected, so you can adjust the effiency on the beersmith to coinside with the OG that you have gotten to work out your percentage. Make sure that you have the gravity for the preboil and not the post boil, as they will be much different (depending on when you take the measurement).
you can find the expected preboil gravity by clicking on the preview brewsheet button near the top.
as for volumes, remember that you lose alot of water in your grain, and equipment, but if you say that most of your water was drained into the kettle, then you might not have done the right calculations to ensure you ahve the right final volume.
1kg of grain will absorb 1L of water. in the mash, so if you ahve 5kg of grain, and you mash with 15, you will only get 10L back. then, if you sparge with the 5+3L/kg =20L, that will give you a total volume of 30L in the kettle, which is fine for the volume you want.
Depending on how vigourous your boil is, you will loose about 20% of the volume of your beer. which still leaves you 24L litres.
I do find that you will never be able to get all that volume out of the kettle and into your fermenter becuase you have all you hot break and hop residue at the bottom.. also depening on your pickup, you may have to leave a couple of litres behind.
that maybe the reason why you only end up with 21L instead of 24L.
The first time i brewed, i was expecting 24L and only got 18... getting the volumes right comes down to knowing where you loose you water during the process, and getting used to your equipment. takes a bit of time...
Now i brew for a final batch volume of 26L becuase i know by the end, i will only end up with about 23L due to loss at certain stages of the process.
I hope that helps.
I freely admit that I was Very Very Drunk....
"They speak of my drinking, but never consider my thirst."