Pre Boil Gravity
- Thread starter PaulReece
- Start date
Oginme
Grandmaster Brewer
Your gravity reading is only part of the equation. What was your volume versus what the expected volume was supposed to be?
Then add up the gravity points:
(Target OG-1)*1000 * target volume = expected gravity points
(Actual OG-1)*1000 * actual volume = actual gravity points
If the numbers are pretty close then the issue is a volume issue and you need to look at your equipment profile
-- you are extracting the correct amount of sugars based upon your projected efficiency
-- your water volumes are too high
If the actual gravity points is greater than the expected points, then your equipment profile is off and you had a better conversion/extraction efficiency than you had planned on
-- your water volumes are too high
-- you need to adjust your profile for a higher efficiency
If the expected gravity points is greater than the expected points, then you had poor conversion/extraction efficiency
-- there are a number of issues that lead to low efficiency. So breaking it down further:
* if your water volumes are close (predicted vs actual):
-- look at the crush of the grain, it may not be fine enough
-- look at your mashing time, you may not have enough time for extraction of the sugars once converted
-- you may not have fully dispersed the grains into your mash water, leading to dough balls
-- your sparge was poorly performed -- not enough mixing, contact time, channeling of the sparge water, etc.
-- you will need to adjust your recipe efficiency to reflect your actual results
* if your actual water volume is much greater than your predicted volume:
-- the above list is still applicable, but you also need to look at your equipment profile and readjust the water volumes
* if your predicted volume is much greater than your actual volume:
-- you really have a mess. Start by adjusting your equipment profile for volumes and actual efficiency
-- follow list above for troubleshooting your process
Then add up the gravity points:
(Target OG-1)*1000 * target volume = expected gravity points
(Actual OG-1)*1000 * actual volume = actual gravity points
If the numbers are pretty close then the issue is a volume issue and you need to look at your equipment profile
-- you are extracting the correct amount of sugars based upon your projected efficiency
-- your water volumes are too high
If the actual gravity points is greater than the expected points, then your equipment profile is off and you had a better conversion/extraction efficiency than you had planned on
-- your water volumes are too high
-- you need to adjust your profile for a higher efficiency
If the expected gravity points is greater than the expected points, then you had poor conversion/extraction efficiency
-- there are a number of issues that lead to low efficiency. So breaking it down further:
* if your water volumes are close (predicted vs actual):
-- look at the crush of the grain, it may not be fine enough
-- look at your mashing time, you may not have enough time for extraction of the sugars once converted
-- you may not have fully dispersed the grains into your mash water, leading to dough balls
-- your sparge was poorly performed -- not enough mixing, contact time, channeling of the sparge water, etc.
-- you will need to adjust your recipe efficiency to reflect your actual results
* if your actual water volume is much greater than your predicted volume:
-- the above list is still applicable, but you also need to look at your equipment profile and readjust the water volumes
* if your predicted volume is much greater than your actual volume:
-- you really have a mess. Start by adjusting your equipment profile for volumes and actual efficiency
-- follow list above for troubleshooting your process
TAHammerton
Grandmaster Brewer
Hi Paul,
If you got your grain crushed I can all but guarantee the crush was too course. When I got my own grain mill my yields dramatically increased. For some reason Home brew stores are so petrified of stuck mashes that a lot of grains get through un-crushed. there are several good threads on this forum concerning how to set your mill and what a good crush should be.
If you got your grain crushed I can all but guarantee the crush was too course. When I got my own grain mill my yields dramatically increased. For some reason Home brew stores are so petrified of stuck mashes that a lot of grains get through un-crushed. there are several good threads on this forum concerning how to set your mill and what a good crush should be.