Question about full volume mash BIAB

Question: I'm going to do this as a full BIAB with no sparging. It's a 6 gallon batch with a total of 11.25 lbs of grain. Beer smith is saying I need a total of 9.67 gallons to hit my 8 gallon pre boil volume. I know the grain will Obsorbe some water but 9.67 total in mash sounds like a lot to hit my 8 gallon pre boil, no??

Does the 9.67 gallons include things like hop absorption, trub loss, etc.?

Do you really boil off 2 gallons? Most of my BIAB are 8-9 gallons to start for a 5.5 finish volume. And I'm always more like 13-15# grain bill... I've started with 10 gallons on a big lager that's getting a 90 min boil.

I just did a 5 gallon batch of Yoopers oatmeal Stout yesterday under the same conditions (11 pound grain bill) and hit my OG at 1.052, right on the spot! So I know that my volumes are spot on as well. That said, I filled the 10 gallon kettle with 8 gallons of strike water, heated to 162° and added the grains (bag already in place) and keyed in 156° in my PID for the mash in.

This brought my mash to within 1/2 of the top rim of the kettle. After the boil, I pulled the bag out so that it hovered over the kettle (ratchet pulley system) and added the makeup water over the grain bag. Call it sparging or a rinse or whatever, *its all the same, until I had my 8 gallons for pre-boil.

In may case, I had to make up almost 2 gallons of water to get to my 8 gallons, this is normal for me so I always hold 3 gallons of strike water in a drink cooler at 162° just for that purpose.

If you come up with a solution other than buying a 15 gallon kettle, please let us know! I have to add water every time.

Probably something with your equipment or mash profile. When I put in an 11.25 lb grain bill for a 6 gal batch with 2 gal boil off, it tells me to start with 9.06 gal of water. Can you post screen shots of the equipment and mash profiles used for your recipe?

Brew on

Firewalker11 said:

I just did a 5 gallon batch.....
In may case, I had to make up almost 2 gallons of water to get to my 8 gallons....If you come up with a solution other than buying a 15 gallon kettle, please let us know!

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Make 3.5 gallon batches. Your pot's too small. You could also do full volume by using DME to make up gravity and lowering your grain bill.

There's no way to get a 10# load in a 5# sack.

jcs401 said:

Question: I'm going to do this as a full BIAB with no sparging. It's a 6 gallon batch with a total of 11.25 lbs of grain. Beer smith is saying I need a total of 9.67 gallons to hit my 8 gallon pre boil volume. I know the grain will Obsorbe some water but 9.67 total in mash sounds like a lot to hit my 8 gallon pre boil, no??

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Typically, each lb of grain will absorb about half a quart of water. So your 11.25 lbs of grain will absorb about 5.6 quarts of water or close to 1.4 gallons.

9.67 - 1.4 = ~8.2 gallons.

Depending upon the deadspace in your mash tun, it's not too far off.

Here is my profile. I use a 44qt bayou kettle.
View attachment ImageUploadedByHome Brew1451943263.985108.jpg

And the recipe:View attachment ImageUploadedByHome Brew1451943351.042741.jpg

You don't show your mash profile, but it appears you are not using a BIAB profile. BS default grain absorption for traditional MLT's is 0.12 gal/lb (0.96 fl oz/oz), but for BIAB the default absorption is 0.073 gal/lb (0.586 fl oz/oz). You can find the absorption values under "Tools -> Options -> Advanced." The difference in absorption rates is the difference between needing 1.35 gal vs. 0.824 gal to account for absorption.

I think BS gives you strike water volumes at strike temperature, so for 160°F strike water that is about 2% higher than room temp water volume. It gives pre-boil volume at 212°F, and that is about 4% higher than room temp volume.

If you want to know what volume of room temp water to start with, and have all the parameters that affect your volume calculations in one place, use the calculator here: http://pricelessbrewing.github.io/BiabCalc/

Brew on

paperairplane said:

Make 3.5 gallon batches. Your pot's too small. You could also do full volume by using DME to make up gravity and lowering your grain bill.

There's no way to get a 10# load in a 5# sack.

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Oh HELL no! Why on earth would I do that? Adding water through the grain to scavenge any residual sugars to make up the water volume is not a big deal.

DME or extracts, oh HELL no!

Recipe: Yooper's Oatmeal Stout TYPE: All Grain
Style: Oatmeal Stout
---RECIPE SPECIFICATIONS-----------------------------------------------
SRM: 32.5 SRM SRM RANGE: 22.0-40.0 SRM
IBU: 32.4 IBUs Tinseth IBU RANGE: 25.0-40.0 IBUs
OG: 1.054 SG OG RANGE: 1.048-1.065 SG
FG: 1.016 SG FG RANGE: 1.010-1.018 SG
BU:GU: 0.597 Calories: 196.0 kcal/12oz Est ABV: 5.1 %
EE%: 75.00 % Batch: 5.50 gal Boil: 6.98 gal BT: 60 Mins

---WATER CHEMISTRY ADDITIONS----------------


Total Grain Weight: 11 lbs Total Hops: 2.00 oz oz.
---MASH/STEEP PROCESS------MASH PH:5.20 ------
>>>>>>>>>>-ADD WATER CHEMICALS BEFORE GRAINS!!<<<<<<<
Amt Name Type # %/IBU
7 lbs Pale Malt, Maris Otter (3.0 SRM) Grain 1 63.6 %
1 lbs Oats, Flaked (1.0 SRM) Grain 2 9.1 %
12.0 oz Victory Malt (25.0 SRM) Grain 3 6.8 %
10.0 oz Pale Chocolate Malt (200.0 SRM) Grain 4 5.7 %
8.0 oz Black Barley (Stout) (500.0 SRM) Grain 5 4.5 %
8.0 oz Caramel/Crystal Malt - 80L (80.0 SRM) Grain 6 4.5 %
7.0 oz Wheat, Flaked (1.6 SRM) Grain 7 4.0 %
2.0 oz Chocolate Malt (450.0 SRM) Grain 8 1.1 %
1.0 oz Barley, Flaked (1.7 SRM) Grain 9 0.6 %


Name Description Step Temperat Step Time
Saccharification Add 31.14 qt of water at 163.6 F 156.0 F 60 min
Mash Out Heat to 168.0 F over 7 min 168.0 F 10 min

---SPARGE PROCESS---
>>>>>>>>>>-RECYCLE FIRST RUNNINGS & VERIFY GRAIN/MLT TEMPS: 72.0 F/72.0 F
>>>>>>>>>>-ADD BOIL CHEMICALS BEFORE FWH
If steeping, remove grains, and prepare to boil wort

---BOIL PROCESS-----------------------------
Est Pre_Boil Gravity: 1.045 SG Est OG: 1.054 SG
Amt Name Type # %/IBU
2.00 oz Willamette [4.70 %] - Boil 60.0 min Hop 10 32.4 IBUs


---FERM PROCESS-----------------------------
Primary Start: 07 Oct 2012 - 4.00 Days at 67.0 F
Secondary Start: 11 Oct 2012 - 10.00 Days at 67.0 F
Style Carb Range: 1.90-2.50 Vols
Bottling Date: 21 Oct 2012 with 2.3 Volumes CO2:
---NOTES------------------------------------
9:14 - MASH IN (21.5 qts Temp at 158 deg)
9:44 - Temp at 156 deg
10:14 - Temp at 154 deg
10:17 - MASH OUT (added 7.7 qts of boiling H2O... Brought temp to 164 deg)
Pre-Boil Volume = 6.5 gallons
Pre-Boil SG = 1.047
~10:37 - FLAME ON
10:47 - Boil started
11:49 - FLAME OUT
Post Boil Volume ~5 gallons

OG = 1.057

I've used Beersmith for over 6 years while doing 3V brewing but had some trouble when setting it up for BIAB. I use http://biabcalculator.com to check my numbers and it has been very reliable so far (in the 20+ BIAB batches that I've done)

I also used BS water numbers and had to boil for two hours to get the volume correct. Go with another calculator.

Firewalker11 said:

Oh HELL no! Why on earth would I do that? Adding water through the grain to scavenge any residual sugars to make up the water volume is not a big deal.

...

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You asked for a solution on how to full volume and no sparge without an equipment upgrade. I gave you the correct answer.

Now go buy a bigger kettle.

paperairplane said:

You asked for a solution on how to full volume and no sparge without an equipment upgrade. I gave you the correct answer.

Now go buy a bigger kettle.

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No need, even the three tier guys sparge, so do I by adding makeup water.