Hi folks,
I've done 2 partial mash batches in a row and both times the actual OG was ~11pts lower than BS predicted. Here is the info I hope will help to figure this out:
Beersmith v2.3.7
Type
--
Partial Mash
Equipment profile
--
Boil vol: 2.25gal
Boil time: 60mins
Boil off: 0.5gal
Loss to trub: 0.18gal
Top up: 1gal
Batch vol: 2.5gal
Process
--
- Mashed 2.5lbs grain
- BS predicted 1.030 post-mash gravity and I measured 1.030 (yay!)
- 60min boil
- Added 3lb LME w/ 5mins left (stirred in well, did not stick to bottom of pot)
- Cooled and topped up to 2.5gal in fermenter
- BS predicted 1.071 OG, I measured 1.060.
Thoughts
--
- I adjusted the gravity readings for the sample temp and my hydrometer's calibaration temp.
- I thought the LME might be low-SG or something but I measured it and it came out at 1.038 which is what BS has for it.
- I stirred the wort very well after adding the top-up water (on the second batch, after reading that this could be the cause of the problem the first time it happened).
- I thought I might be losing more to trub than I thought, but when I tweak the equipment profile to increase trub loss and increase top-up water as a result, the OG prediction doesn't change, which I would think it would (loss to trub = loss of sugar?).
Thanks for any assistance.
Marc
I've done 2 partial mash batches in a row and both times the actual OG was ~11pts lower than BS predicted. Here is the info I hope will help to figure this out:
Beersmith v2.3.7
Type
--
Partial Mash
Equipment profile
--
Boil vol: 2.25gal
Boil time: 60mins
Boil off: 0.5gal
Loss to trub: 0.18gal
Top up: 1gal
Batch vol: 2.5gal
Process
--
- Mashed 2.5lbs grain
- BS predicted 1.030 post-mash gravity and I measured 1.030 (yay!)
- 60min boil
- Added 3lb LME w/ 5mins left (stirred in well, did not stick to bottom of pot)
- Cooled and topped up to 2.5gal in fermenter
- BS predicted 1.071 OG, I measured 1.060.
Thoughts
--
- I adjusted the gravity readings for the sample temp and my hydrometer's calibaration temp.
- I thought the LME might be low-SG or something but I measured it and it came out at 1.038 which is what BS has for it.
- I stirred the wort very well after adding the top-up water (on the second batch, after reading that this could be the cause of the problem the first time it happened).
- I thought I might be losing more to trub than I thought, but when I tweak the equipment profile to increase trub loss and increase top-up water as a result, the OG prediction doesn't change, which I would think it would (loss to trub = loss of sugar?).
Thanks for any assistance.
Marc