What Absorption Rate?

[djonesax]

What absorption rate do you all use for your AG recipes? This past brew, something happened and I had a gallon less after the mash than expected.

I have brewed the same beer 5 times in a row now changing little things each time. This time the change was a mash out at 168 degrees for 15 minutes but ended up being about 25 because I got sidetracked on something else.

Here is my grain bill..
11.00 lb Pale Malt (6 Row)
9.00 lb Pilsner (2 Row)
3.00 lb Maize, Flaked
1.75 lb Caramel Malt - 60L

Beersmith said I needed 17.75 gallons of water and after mash I'd have 14.78 gallons to boil but I ended up with 13.75 to boil. I could tell the drained mash-tun was heavier than normal like the grain had soaked up more water than usual.

Thanks,

David

 

[Yooper]

I almost always lose .125 gallon per pound of grain to absorption in the mash.

I would have "lost" about 3 gallons in the mash, with a nearly 25 pound grainbill. Did you measure the amount you added correctly?

 

[kh54s10]

I never worry about grain absorption. I do a batch sparge. I add the water called for in Beersmith. I think it is about 1.25 quarts per pound of grain for the mash. I drain the tun, measure the wort collected, then sparge with somewhere over half of the amount needed for preboil. I do a second sparge to get the full preboil amount.

I do the second sparge so that I don't end up with not enough or a lot left in the mash tun.

 

[djonesax]

I never worry about grain absorption. I do a batch sparge. I add the water called for in Beersmith. I think it is about 1.25 quarts per pound of grain for the mash. I drain the tun, measure the wort collected, then sparge with somewhere over half of the amount needed for preboil. I do a second sparge to get the full preboil amount.

I do the second sparge so that I don't end up with not enough or a lot left in the mash tun.

I thought about adding more water but my hydrometer broke during the process so I couldn't test it to see the preboil gravity.

What efficiency are you getting with the batch sparge?

 

[kh54s10]

I use a Corona style mill so I don't know if my crush has any effect. I have Beersmith set to 68% and the measured is usually about 70%

This is also something I don't worry too much about.

I usually get very close on the numbers and the beers taste great, so......

 

[Grannyknot]

I always use 0.10 gal/lb.

 

[pumahunter]

are you accounting for dead space as well?

 

[duboman]

Are you sure you just didn't get a stuck sparge since you fell short on the pre boil volume and had more wort left in the tun, it happens. I use .12 gallons per pound

 

[djonesax]

are you accounting for dead space as well?

I don't really have much dead space as I have a pickup tube that is right on the bottom under the false bottom

 

[djonesax]

Are you sure you just didn't get a stuck sparge since you fell short on the pre boil volume and had more wort left in the tun, it happens. I use .12 gallons per pound

See that's the thing, there wasn't any more free flowing wort in the tun. It was as if the grain just super absorbed that day.

 

[duboman]

See that's the thing, there wasn't any more free flowing wort in the tun. It was as if the grain just super absorbed that day.

That would be odd........

Brewing AG for 5 years and over 200 batches I've never had a batch that absorbed more water than the normal .12 gallons per pound, my guess is you erred in your sparge water volume or left behind more than you think.

 

[sky4meplease]

.093 gal/lb

Not .10 gal/lb