BIAB volumes - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > BIAB volumes

Thread Tools
Old 02-16-2010, 01:14 AM   #1
Mar 2008
Milford, MI
Posts: 19

I seem to be stuck in a rut on water volumes! I plan to start doing all-grain BIAB brews, but my preference is to sometimes do 2.5 or 3 gallon batches or 5 gallon batches. I need some help in determining my water volumes. I have both a 5-gallon stainless kettle and 9-gallon stainless kettle. I use a standard turkey fryer to boil, assume 60 minutes boils. Since I plan to use the BIAB method, I want to make sure I get my initial water volume correct.


1) How much should I assume I boil off in 60 minutes for 2.5 or 3 gallon batches and 5 gallon?
2) How much should I assume for grain absorption?
3) How much should I assume for lost to trub for 2.5 or 3 gallon batches and 5 gallon?

Thanks a lot for any help!

Reply With Quote
Old 02-16-2010, 01:23 AM   #2
Sep 2008
WarehamI?, Massachusetts
Posts: 700
Liked 39 Times on 29 Posts

I'm exclusive BIAB.

1. Measure it. I get 2 gallons an hour.
2. I'm dialing this one in. I squeeze the heck out of my bag and get .05# per gallon absorption on around 10# of grain. I have a feeling this number is influenced by the amount of grain but haven't proven it yet.
3. I use a hop sock and I dump it all in the fermenter so I can't help you there.
I don't have "hobbies", I'm developing a robust Post-Apocalyptic skill set.
Masstoberfest Cup Winner 2014
Facebook Brew In A Bag Group
Facebook Southcoast Homebrewers Association
Partigyles Gone Wild on Basic Brewing Radio <-Hey, that's me!

Reply With Quote
Old 02-16-2010, 02:58 AM   #3
bigjoe's Avatar
Feb 2009
Blue Springs, MO
Posts: 258
Liked 3 Times on 3 Posts

1) Like Daddymem said measure it. I evap 1.5 gallons in 75 minute boil
2) Good rule of thumb is .1 gallon which is what I get. So roughly 1 gallon on a "normal gravity" beer. I just clamp my bag to the side of the keggle and let it drain.
3) I use a hop sock also and end up with very little trub in the kettle. I don't account for fermenter loss, but probably should. I usually have well over 5 gallons of beer in the end.

So my calculations go something like this. I usually just figure 1 gallon for grain absorbtion. I know I boil off 1.5 gallons in 75 minute boil. For a total of 2.5 gallons of water over the quantity of beer I get. I start with 8 gallons of water. I calculate my recipes for 5.5 gallons.

Reply With Quote
Old 02-16-2010, 03:39 AM   #4
bakins's Avatar
May 2008
West Georgia
Posts: 728
Liked 6 Times on 6 Posts

I boil off a gallon per hour and always do 90minute boils.

I do 10 gallon batches, and loose a gallon between break, trub, etc, so I aim for 11 gallons at end of boil.

So I start with 12.5 gallons at start of boil. I average .1 gallons per pound absorption, so it's pretty simple math to figure the amount of "strike" water:
12.5 + .1 * pounds of grain

When I do a partial mash, I generally just aim for 3.25 quarts per pound as long as it will fit into my pot. (I wrote a little script that figures it out for me.) I do this a lot as I bought a 15 gallon kettle rather than a 20, like I should have. But a few pounds of DME is no big deal... So, make sure your pot can handle the volume if you feel dirty for using a little extract
No sparge, no chill, no MLT, no HLT, no propane, no worries...

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Volumes of CO2 farmbrewernw General Beer Discussion 22 02-07-2014 04:46 PM
Volumes of C02 B33R Bottling/Kegging 3 12-20-2009 01:44 PM
How many volumes of Co2 do i need for my APA and IPA? bgough Beginners Beer Brewing Forum 1 02-22-2009 02:44 AM
Volumes Co2 for IPA? EamusCatuli Bottling/Kegging 2 08-28-2008 06:41 PM
Pitch volumes Seabee John General Techniques 7 01-18-2008 03:13 PM

Forum Jump