Mash Water Volume (BIAB)

[typebrad]

So, we're all focused on a proper wort volume considering boil-off, final fermenter volume, etc. But I have a question about the initial mash volume.

In full grain, the idea is to barely cover the grain bed.

If I'm using 10-12 pounds of grain in a 10 or 15 gallon kettle, how do I determine the initial mash (water) volume?

There are calculators that take grain absorption into consideration, but should I be concerned if my grain is "swimming" when I add it to the mash water? Is too much water a bad thing when mashing?

Any input is much appreciated.

 

[typebrad]

Partially answering my own question .... If your water volume isn't correct, your mash temp will be off. If I put way too much 168 degree water in with a small grain bill, my temp will not drop to proper mash temp.

Help?

 

[GrogNerd]

IIRC, it's 1 to 2 quarts per pound of grain with 1.25 to 1.75 being typical

10 lbs of grain = 10 to 20 (again, typically 12.5 to 17.5) quarts of water. depends a lot on the style and the recipe

 

[balrog]

There are all kinds of calculators that help determine volume (typ you mash 1.25-1.5 qt water/lb grain) and then the infusion temp to get that strike water to, given grain temp, mash tun temp and mash tun wt and spec heat. Programs like BeerSmith have them built in, and other are online only a quick Google away. (example)

Edit: Dang! GrogNerd, you're fast!

 

[TopherM]

1.25-1.5 qt water/lb grain

WHOA! That is correct for traditional brewing, but not for BIAB!

With BIAB, you start with the ENTIRE starting water volume. So, you have to calculate everywhere you lose volume, and work backwards from there. The numbers are different for your unique brew setup and methods, so you really need to keep accurate numbers the first couple times you brew and figure it out. Working backwards:

Ending beer volume
+
Loss to trub when you rack out of primary
+
Loss to contraction during cool down (typically around 0.25-0.3 gallons)
+
Loss to trub when you transfer from kettle to primary
+
Loss to boiloff (direct relationship to the diameter of your pot)
+
Loss to grain absorption
=
Starting volume

I do 5.5 gallon BIAB batches in a 11 gallon gallon Bayou Classic pot, and typically start with 6.8-7.2 gallons of water, depending on the size of the grain bill, which should give you a good starting point, but try to measure your equipment's and process' specific losses at least once, as it will be unique.

Good luck!

 

[KeninMN]

According to the Sticky at the beginning of the BIAB board, your mash volume is all the water you're ever going to use. So, assuming you're doing a 5-gallon batch, and accounting for grain absorption and evaporation, you'd start with something like 7.5 gallons of strike water for a no-sparge BIAB session.

https://www.homebrewtalk.com/f244/biab-brewing-pics-233289/

Also, it's been noted that efficiency is inversely proportional to mash water volume. That is the more water you mash with the higher your efficiency.

http://braukaiser.com/wiki/index.php?title=Effects_of_mash_parameters_on_fermentability_and_efficiency_in_single_infusion_mashing

 

[wilserbrewer]

10 -12 lbs of grain for a 5 gallon batch of finished beer will have you mash in with around 8 gallons at 158 - 160 ball park.

try this, but remember there is no need to overcomplicate it, cheers...
http://www.simplebiabcalculator.com/

 

[typebrad]

Thanks for all of the responses! I'm making the jump into BIAB with my next beer and am trying to study up as much possible. The trub loss is always a mystery to me. My goal would be 5.5 fermenting, I believe. That will allow for trub loss and put me at about 5 gallons to bottle. I hope. Guess that depends on grain bill. Time to experiment!


/Will always still be figuring it out/

 

[GrogNerd]

/Will always still be figuring it out/

I first brewed 20 years ago, but had quit for 17 years and only a year & 1/2 ago started again.

I figure your quote will always be true for me no matter how much I brew

 

[knelson13A]

/Will always still be figuring it out/

This is the truth. You never stop learning.

 

[Peruvian802]

I've looked over a few calculators and would be unable to BIAB on my set up, if I trusted them. In my Winco 40qt pot, most calculators call for 8.5-8.75 gal of water, so I would be unable to fit a moderate grain bill. Instead, I start with a slightly lower volume of water, pull the grains after mashing, then use a pour over sparge to get up to pre-boil volume.

For me it's easier to add water pre-boil than try and boil it off. Besides, by double crushing my BIAB grains I get ridiculous efficiency and can lower my pre-boil gravity to what I want by sparging.

 

[HBngNOK]

I think the Water Requirements for BIAB calculator on the home page looks good.