Absorption and Tun Loss Advice Needed - Home Brew Forums
Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > Absorption and Tun Loss Advice Needed

Reply
 
Thread Tools
Old 02-24-2012, 07:50 PM   #1
Guidry
Recipes 
 
Jan 2009
Denham Springs, La
Posts: 636
Liked 33 Times on 30 Posts



New to AG and have brewed the same recipe twice (13.25lbs of grain). I have the common 10 gallon round orange tun. Ran the recipe thru several different software apps and all of them said to use approx 4.15 gals for the initial infusion. All of them suggest about a 0.13gal/lb absorption rate. Well, in both cases, I ended up with approx 4.25 gal in the mash due to adjustments to get the proper temp and both times I collected 3.5 gal. Even if I consider all of the "loss" due to absorption, that gives me a 0.06gal/lb absorption. Seems low right? And that does not assume any loss in the bottom of the tun. Any advice on how to determine the proper loss values for absorption and tun loss in my case?

Second, while I'm asking questions, all of the apps also recommended adding 5 gals for sparging (this with a 6.75 gal pre-boil volume specified). Assuming that the grain will have already absorbed all the water it can, and whatever tun loss I have will already still be in the tun, doesn't that volume seem way high? From my understanding, the sparge volume should be equal to the pre-boil desired volume minus the volume collected from the initial infusion, right?



 
Reply With Quote
Old 02-24-2012, 08:11 PM   #2
afr0byte
Recipes 
 
Aug 2010
Vermont
Posts: 1,451
Liked 74 Times on 62 Posts


Quote:
Originally Posted by Guidry View Post
New to AG and have brewed the same recipe twice (13.25lbs of grain). I have the common 10 gallon round orange tun. Ran the recipe thru several different software apps and all of them said to use approx 4.15 gals for the initial infusion. All of them suggest about a 0.13gal/lb absorption rate. Well, in both cases, I ended up with approx 4.25 gal in the mash due to adjustments to get the proper temp and both times I collected 3.5 gal. Even if I consider all of the "loss" due to absorption, that gives me a 0.06gal/lb absorption. Seems low right? And that does not assume any loss in the bottom of the tun. Any advice on how to determine the proper loss values for absorption and tun loss in my case?

Second, while I'm asking questions, all of the apps also recommended adding 5 gals for sparging (this with a 6.75 gal pre-boil volume specified). Assuming that the grain will have already absorbed all the water it can, and whatever tun loss I have will already still be in the tun, doesn't that volume seem way high? From my understanding, the sparge volume should be equal to the pre-boil desired volume minus the volume collected from the initial infusion, right?
First, determine how much water you lose to the mash tun by adding a gallon to the tun and then draining as much as possible. This is roughly how much you lose to the mash tun. Then, to get the absorption you take initial_vol - tun_loss - volume in kettle. Based on your example, it seems your volume measurements could be off somewhere.



 
Reply With Quote
Old 02-24-2012, 09:17 PM   #3
tre9er
Recipes 
 
Jan 2012
Lincoln, NE
Posts: 4,369
Liked 242 Times on 197 Posts


My absorption is about 0.1g/lb. Some softwares start at 0.19 which is about twice as much. I also don't boiloff as much, but then again I try to control my boil quite a bit cause I usually have a near full pot volume
__________________
_________________________________
Skal!
Den Faaborg Bryggeri

Quote:
Originally Posted by davekippen View Post
Open log Fermenting and gas-can secondary?? I am planning my next brew right now!!

 
Reply With Quote
Old 02-24-2012, 09:18 PM   #4
tre9er
Recipes 
 
Jan 2012
Lincoln, NE
Posts: 4,369
Liked 242 Times on 197 Posts


Quote:
Originally Posted by Guidry View Post
Second, while I'm asking questions, all of the apps also recommended adding 5 gals for sparging (this with a 6.75 gal pre-boil volume specified). Assuming that the grain will have already absorbed all the water it can, and whatever tun loss I have will already still be in the tun, doesn't that volume seem way high? From my understanding, the sparge volume should be equal to the pre-boil desired volume minus the volume collected from the initial infusion, right?
Yes. Don't oversparge or else you're just getting watered down beer.
__________________
_________________________________
Skal!
Den Faaborg Bryggeri

Quote:
Originally Posted by davekippen View Post
Open log Fermenting and gas-can secondary?? I am planning my next brew right now!!

 
Reply With Quote
Old 02-24-2012, 09:29 PM   #5
Guidry
Recipes 
 
Jan 2009
Denham Springs, La
Posts: 636
Liked 33 Times on 30 Posts


Quote:
Originally Posted by afr0byte View Post
First, determine how much water you lose to the mash tun by adding a gallon to the tun and then draining as much as possible. This is roughly how much you lose to the mash tun.

I assumed this at first also, and then I came to the realization that this is incorrect. In an empty tun, I lose about 1/2 gallon. However, once the tun is filled, a large portion of that volume beneath the drain elevation is occupied by grain, thereby displacing a lot of the volume of water. By your (and my original) method, assuming the measured 0.5 gallon loss, the volume absorbed would be approx 1 quart or 0.02gal/lb.

 
Reply With Quote
Old 02-24-2012, 10:10 PM   #6
1MadScientist
Recipes 
 
Apr 2011
Panhandle of Florida, USA
Posts: 604
Liked 37 Times on 30 Posts


Do you have your beverage cooler at a counter top height and use a drain hose, draining to floor level? This will create a siphon. I "tested" with water using my copper manifold and got it all drained and I heard it sucking it dry, well, leaving about 6 ounces.

http://www.flickr.com/photos/madscie...us/5344928638/
http://www.flickr.com/photos/madscie...us/5346729576/

Prosts...


__________________
In Cat Beers - I've Only Had One

BIABrewer.info / Closed-system pressurized fermentation technique

Brewing with MS; https://goo.gl/photos/puZUgG8QRp7p8gLd9

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Last Minute Advice Needed Pombe All Grain & Partial Mash Brewing 8 04-30-2011 03:04 PM
Extra Water Loss From Grain Absorption??? Schlenkerla All Grain & Partial Mash Brewing 13 10-11-2010 12:05 AM
Advice needed for APA Bosium All Grain & Partial Mash Brewing 3 09-09-2009 06:25 PM
What to do, what to do? Advice needed beergutbrew All Grain & Partial Mash Brewing 6 04-04-2009 01:26 AM
Advice Needed swampdog All Grain & Partial Mash Brewing 4 05-02-2005 09:28 PM


Forum Jump