Need help with calculating 11 gallon batch with BIAB keggle

[jrodder]

So, I would like to do a double batch with my current setup. Weight of the bag isn't an issue, I use a pulley system into the ceiling. I have enough space to mash this beer, but obviously I plan on squeezing and sparging a bit through the grain bag to end up with ~13 gallons to start the boil. I am trying to do this in beersmith but I'm not having much luck. It makes a lot of calcs based on factors that I am going to change. Has anyone else done this? Any pointers? Here's the planned recipe:

BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: Jared's Pale Ale
Brewer: J-Rod
Asst Brewer: 
Style: American Pale Ale
TYPE: All Grain
Taste: (30.0) 

Recipe Specifications
--------------------------
Boil Size: 15.39 gal
Post Boil Volume: 13.62 gal
Batch Size (fermenter): 12.08 gal   
Bottling Volume: 11.63 gal
Estimated OG: 1.065 SG
Estimated Color: 20.5 SRM
Estimated IBU: 19.3 IBUs
Brewhouse Efficiency: 70.00 %
Est Mash Efficiency: 75.9 %
Boil Time: 75 Minutes

Ingredients:
------------
Amt                   Name                                     Type          #        %/IBU         
28 lbs                Pale Malt (2 Row) US (2.0 SRM)           Grain         1        90.3 %        
2 lbs                 Munich Malt (9.0 SRM)                    Grain         2        6.5 %         
1 lbs                 Carafa III (525.0 SRM)                   Grain         3        3.2 %         
1.00 oz               Columbus (Tomahawk) [14.00 %] - Boil 60. Hop           4        19.3 IBUs     
4.00 oz               Cascade [5.50 %] - Boil 0.0 min          Hop           5        0.0 IBUs      
3.00 oz               Columbus (Tomahawk) [14.00 %] - Boil 0.0 Hop           6        0.0 IBUs      
4.00 oz               Centennial [10.00 %] - Dry Hop 0.0 Days  Hop           8        0.0 IBUs      
1.0 pkg               American Ale II (Wyeast Labs #1272) [124 Yeast         7        -             


Mash Schedule: BIAB, Light Body
Total Grain Weight: 31 lbs
----------------------------
Name                    Description                    Step Temperat Step Time     
Saccharification        Add 70.64 qt of water at 154.9 147.9 F       90 min        
Mash Out                Heat to 168.0 F over 7 min     168.0 F       10 min        

Sparge: Remove grains, and prepare to boil wort
Notes:
------
Step by Step
Mash in at 152 °F (67 °C) for 40 minutes. Sparge to collect ~6.5 gallons (25 L) in your kettle to achieve 5.5 gallons (21 L) at knockout. Boil for a grand total of 75 minutes. Just after knockout, toss in the knockout hops and begin whirlpool. You can either run your pump for 10 minutes or stir for a minute and then let spin down and settle. After 30 minutes have gone past after knockout, cool the wort down to 65 °F (18 °C) and pitch a healthy dose of yeast into fermenter. After final gravity has been achieved, add clarifying agent such as polyclar. Allow three days for clarifying agent to settle, then add first set of dry hops to primary fermenter. After 7 days, rack beer off dry hops and yeast cake either into a keg or bottle. Try your best to keep oxygen at bay during the racking or bottling process.

Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------

 

[greyghost]

Try this http://biabcalculator.com/
I don't find Beer Smith to handy for BIAB.

 

[haeffnkr]

I use tastybrew http://www.tastybrew.com/calculators/recipe.html
My numbers are spot on.
I use 13 gallons for my pre boil number and 12 for the finish volume.

I make 12 gallon batches in my keggle.

I heat 15 gallons water, then drain off 3 to a bucket for sparge.
I mash with 12 gallons of water and around 20 pounds of grain, that gives me volume of 14 gallons.
After the mash I pull the bag and put it in a mash bucket with holes in it, then put the 3 gallons of sparge water on top of the bag/grain.
I crank of the heat on the reaming 10 gallons of wort and let the 3 gallons of sparge drain through the grain, then press it with a plate for a bit.
I add the 3 gallons of sparge wort back to the kettle and boil the 13 gallons down to 12.

hope that helps
Kevin

 

[1MadScientist]

For 31 pounds of grain, I would start with enough strike water so the mash comes up to the welded seam (~11.75 - 11.86 Gal), mash for 90 mins., sparge with (~4.5 - 4.62 Gal) of water (hold some of this back until you get the wort to a boil, then add the rest until the volume is (~ 1 inch) below the welded seam. Boil for 75 mins. Based on my evaporation rate for my keggle ( 0.92 Gal/hour), will be ~ 1.15 Gal evaporation. At flame-out you should have ~12.75 Gal. When wort is cooled to ambient, the trub loss, AND 1 GALLON OF BOILED / COOLED WATER TO THE FERMENTOR ADDED, you should have 12 Gal. of usable wort. Your yeast cake might be ~.89 Gal., so your finished beer should be 11.11 Gal.

 

[jrodder]

For 31 pounds of grain, I would start with enough strike water so the mash comes up to the welded seam (~11.75 - 11.86 Gal), mash for 90 mins., sparge with (~4.5 - 4.62 Gal) of water (hold some of this back until you get the wort to a boil, then add the rest until the volume is (~ 1 inch) below the welded seam. Boil for 75 mins. Based on my evaporation rate for my keggle ( 0.92 Gal/hour), will be ~ 1.15 Gal evaporation. At flame-out you should have ~12.75 Gal. When wort is cooled to ambient, the trub loss, AND 1 GALLON OF BOILED / COOLED WATER TO THE FERMENTOR ADDED, you should have 12 Gal. of usable wort. Your yeast cake might be ~.89 Gal., so your finished beer should be 11.11 Gal.

Awesome, this is exactly the type of info I was after, thanks guys! I kept trying to use calculations with the BIABacus and/or BeerSmith but it just didn't work since I wasn't really doing a full volume mash. Seems like the keggle is just about maxed for this type of recipe when doing this size batch.

 

[1MadScientist]

I used the BIABacus. It gives you all this info and MORE.

 

[jrodder]

Yeah, the issue is likely me not using that BIABacus to its potential. I'll dig in some more, especially after one go with the bigger batch and I have numbers to crunch on.