Returning to Brewing BIAB DigiBoil Capacity Question

[pawleysplayr]

So back in the day....had the 15 gallon 3 tier/3 burner/pump/cc chiller/controlled everything run at brewing. Years ago before anything was available off the shelf. Everything was an automation project as much as a brewing project.
Got completely burned out.

I'm older and lazier now and have been thinking about getting back into a low tech version of brewing for the fun of it.

I have pretty much settled on BIAB using either the DigiBoil 35L or 65L 220V. Would like to avoid sparging and use full volume mashing with fine grain grinds to achieve whatever efficiency is realistic.
For the most part my target gravity beers are gonna be 4-8% ABV at 5.5/6 gallon batches.

Just in general I would prefer the DigiBoil 35L if for no other reason than size in my available space....but I'm concerned that the capacity is not quite large enough for the full volume mashes.

Any of the DigiBoil 35L users out there have any feedback as to actual working recipe mashing/boiling size limits you've run into with this unit?

 

[tracer bullet]

It's not a direct comparison but I think that one is referred to as 9.25 gallons and that's about the volume it's at when it is ready to overflow. The Anvil 10.5 is similar, 10.5 gallons when it's ready to overflow. Anvil owners can get up to ~ 21 pounds of grain in as about a max before you don't have enough water to do a decent job of mashing them. Maybe 22 but it's about to overflow and starting to mash on the dry side. You can do a high OG beer but start having to do some extra work. I would guess the digiboil would be on a similar ratio w/ the size difference, so maybe 18 or 19 pounds?

Hopefully actual owners will answer as well.

 

[doug293cz]

To get a 8.0% ABV beer at an FG of 1.015, you need to have an OG of about 1.073 (per BrewersFriend alternate formula ABV calculator.) If we assume the following:

Post-Boil Volume: 6.0 gal​

Conversion Efficiency: 95%​

Boil-off: 0.75 gal​

Grain absorption rate: ) 0.12 gal/lb (no-squeeze)​

BIAB, no-sparge process​

​

You need 19.7 lb of grain, and 9.11 gal of strike water, giving a mash volume of 10.7 gal (40.5 Liters.) Lauter efficiency works out to ~66%, and mash efficiency to ~63%. Calculations done with my mash/lauter simulator.

Brew on

 

[DuncB]

I'd go with the bigger one, diameter is a little more and a little taller but you'll find the " brewing " much less stressful with the extra capacity. Easy to do the occasional higher abv beer without having to reiterate a mash or partigyle. You'll get better efficiency as well when you do a bigger beer.
As @doug293cz figures indicate you wouldn't get 40.5 litres in a 35 litre digiboil. I expect as well given your past experience you will want to challenge yourself after a while and you'll have the " easy " option to do that.

 

[hopjuice_71]

If one is going to go BIAB in a Digiboil, why not just go with something like an Anvil Foundry, which is basically BIAB with a super sturdy, last forever, SS "bag". Issues with volume/gravity are then easily solved with a pour-over sparge.. ..even with cold-water is fine.

 

[pawleysplayr]

Thank you so much guys for taking the time to respond.
I will be purchasing the 65L version for sure.

@hopjuice_71 I think for this go 'round I would like to try the full volume mash/fine grind in a bag. My thinking is if it doesn't work out I can always add a SS basket to replace the bag later.