At the weekend I did a brew based on the same BeerSmith mobile equipement profile I have been using for a long time, and which has served me well. I haven't used it in over a year, but as far as I can recall I stopped taking pre-boil gravity readings as I always hit my OG and never changed my basic technique. All readings taken at the correct temperature BTW!
As I was reminding myself of the process I did take a pre-boil reading and it was a lot lower than expected ? 1.029 not 1.039.
Changing efficiency in BeerSmith from 77% to 62% made this correct, allowing me to adjust the hop schedule/bitterness (OG now 1.046 not 1.054).
I hit the predicted OG perfectly, but the post-boil volume turned out to be 47l not 40l, and changing the batch volume in BrewSmith meant that the automatic boil volume was correctly predicted (prior to this I had been overriding it), but it also meant that the efficiency needed to be raised back to 77% to get the correct OG (1.046)!
However, this now this means that the predicted pre-boil gravity is back to being too high (1.039 rather than the measured 1.029), so I would have encounterd the same problem measuring the pre-boil gravity as before.
Therefore, efficiency of 62% gets correct pre-boil gravity but 77% gets correct post-boil gravity. Why the anomoly?
I have a 45l mash tun, which is dialled into BeerSmith, and I mash/mash out/sparge with enough water to get a pre-boil volume of 60l (so with this recipe, with 9kg of grain, I used a total of 69l or water).
Am I doing something wrong in BeerSmith such that it doesn't realise that I'm using a lot more water prior to the boil, and therefore thinks that the pre-boil gravity should be higher? I have tried increasing the mash tun volume to 69l to match the actual mash/sparge water volume used, but it makes little difference.
The pre-boil volume, boil off rate, shrinkage, trub loss etc. all seem to be correct, so I also can't understand why the predicted OG of 1.046 is achieved even when the pre-boil gravity is so far off.
Any help greatly appreciated!
As I was reminding myself of the process I did take a pre-boil reading and it was a lot lower than expected ? 1.029 not 1.039.
Changing efficiency in BeerSmith from 77% to 62% made this correct, allowing me to adjust the hop schedule/bitterness (OG now 1.046 not 1.054).
I hit the predicted OG perfectly, but the post-boil volume turned out to be 47l not 40l, and changing the batch volume in BrewSmith meant that the automatic boil volume was correctly predicted (prior to this I had been overriding it), but it also meant that the efficiency needed to be raised back to 77% to get the correct OG (1.046)!
However, this now this means that the predicted pre-boil gravity is back to being too high (1.039 rather than the measured 1.029), so I would have encounterd the same problem measuring the pre-boil gravity as before.
Therefore, efficiency of 62% gets correct pre-boil gravity but 77% gets correct post-boil gravity. Why the anomoly?
I have a 45l mash tun, which is dialled into BeerSmith, and I mash/mash out/sparge with enough water to get a pre-boil volume of 60l (so with this recipe, with 9kg of grain, I used a total of 69l or water).
Am I doing something wrong in BeerSmith such that it doesn't realise that I'm using a lot more water prior to the boil, and therefore thinks that the pre-boil gravity should be higher? I have tried increasing the mash tun volume to 69l to match the actual mash/sparge water volume used, but it makes little difference.
The pre-boil volume, boil off rate, shrinkage, trub loss etc. all seem to be correct, so I also can't understand why the predicted OG of 1.046 is achieved even when the pre-boil gravity is so far off.
Any help greatly appreciated!