Rule of thumb for grain absorption?

[E_Rock]

I have an 8 gallon brew kettle. I also happen to be interested in BIAB. So I'm trying to figure out what is practical for my current setup. According to BIABCalc, I could strike 10lb of grain into ~6.7gal of water. Once I mash and pull the bag, drain and squeeze, what kind of volume should I typically expect?

Is there a rough ratio I can expect or does it vary wildly based upon the grain bill?

 

[doug293cz]

I have an 8 gallon brew kettle. I also happen to be interested in BIAB. So I'm trying to figure out what is practical for my current setup. According to BIABCalc, I could strike 10lb of grain into ~6.7gal of water. Once I mash and pull the bag, drain and squeeze, what kind of volume should I typically expect?

Is there a rough ratio I can expect or does it vary wildly based upon the grain bill?

Depending on how aggressively you squeeze, you should absorb between 0.06 gal/lb and 0.08 gal/lb of grain.

Brew on

 

[wilserbrewer]

I could strike 10lb of grain into ~6.7gal of water. Once I mash and pull the bag, drain and squeeze, what kind of volume should I typically expect? 6 gallons plus minus

Is there a rough ratio I can expect or does it vary wildly based upon the grain bill? 1 gallon loss for every 13-14 lbs of grain

ymmv

 

[petrolSpice]

I get 0.06-0.08 gal/lb if absorption. The more grain, the more absorption I think because it's harder to squeeze and I'm over it sooner.

So 10lb in 6.7 gal, you should be left with 5.9-6.1 gal after removing and squeezing the grain.

 

[E_Rock]

Thanks for the feedback everyone.

My understanding is that boiling wort from fresh grain vs extract, there's a much more foaming due to the hot break. Does this match your experience? I have had great success in taming foaming with a spray bottle of water in all my extract batches. Am I asking for trouble starting the boil with 6 gal of all grain wort in an 8 gal kettle?

 

[SweetStout]

Thanks for the feedback everyone.

My understanding is that boiling wort from fresh grain vs extract, there's a much more foaming due to the hot break. Does this match your experience? I have had great success in taming foaming with a spray bottle of water in all my extract batches. Am I asking for trouble starting the boil with 6 gal of all grain wort in an 8 gal kettle?

You have to be attentive when it first comes to a boil but otherwise you'll be fine. I brewed in an 8.3 gal pot for many years without incident.

 

[E_Rock]

You have to be attentive when it first comes to a boil but otherwise you'll be fine. I brewed in an 8.3 gal pot for many years without incident.

Awesome, great to know!

 

[Chanoc]

If you like me brew in your stove top, by the time you reach boiling... at least half a gal will have evaporated...

 

[E_Rock]

If you like me brew in your stove top, by the time you reach boiling... at least half a gal will have evaporated...

I used my stove for my first few batches, but then I got a Blichmann, which I used on my last couple of brew sessions. It puts out heat like a rocket and my evaporation rate has seriously increased. I'm still trying to get a handle on what to expect each time.

 

[casualbrewer]

I know with my current process I start with 7.5 gallons of water and for 10 pounds of grain I will end up with a little over 6 gallons into the fermenter after the boil and squeezing bag. My boil off rate is either pretty low or I do a good job squeezing the bag. The last 3 or 4 batches my efficiency has been right at 80% or a little higher.

 

[mongoose33]

Thanks for the feedback everyone.

My understanding is that boiling wort from fresh grain vs extract, there's a much more foaming due to the hot break. Does this match your experience? I have had great success in taming foaming with a spray bottle of water in all my extract batches. Am I asking for trouble starting the boil with 6 gal of all grain wort in an 8 gal kettle?

Typically I lose a gallon to evaporation while boiling. Usually I"m in the 6.5-6.75 gallon range to start the boil--and my kettle is 8 gallons.

I also use the spray bottle of water and don't have any trouble controlling the foaming. For me, foaming is much more likely to boil over w/ the hop additions than with the hot break.

*********

I use a mash tun rather than BIAB; with 12 pounds I'll lose a gallon to maybe as much as 1.5 gallons, out of a start of about 8 gallons (strike + sparge).

I might be able to get a little more out but at the very end the wort is just trickling out of the mash tun; I don't worry about the rest.

I think this next time I might weigh up the tun plus grain and see what weight of water is absorbed. My experience, though, is that I'm about .08-.09 gallons per pound of grain.

 

[eadavis80]

We have the same setup with BIAB and an 8-gallon kettle. Mine is the 8-gallon Tall Boy. I start with about 5.5 gallons of water (about an inch or so below the bottom rivet on the kettle). I can mash about 11-12 pounds of grain in there. Yes, you will want to be VERY MINDFUL at the hotbreak - there is very little room there. You'll want your hand on your burner's regulator once you reach 200 degrees after the mash. I bring 3 gallons of water to 170 degrees on my stove about 1/2 way through the mash. On my stove, I have to have it on high for about 30 minutes to get it there. AFter the iodine test, I then pull the bag out, slowly and squeeze as I bring it out. Then, I put the grain bag into a steel milk crate which I put on top of the Tall-Boy kettle. I then sparge with enough water to yield 6 pre-boil gallons (which is about even with that bottom rivet). I pour water over the grain bag with a pitcher of the sparge water slowly. This takes about 15 minutes to pour and I press down on the grain bag with the bottom of the pitcher after each pour. Bring the water to a boil (with the hand on the regulator) and start your boil. This method (as ghetto as it sounds) has worked well for me with pretty good efficiency and tasty beers. It's cheap and easy. A little quirky maybe - but it works.