[skyler]

I’ve been brewing with a current-model Anvil foundry (with a March pump to recirculate, as well as a swirly arm to whirlpool) for about a year and a half, after about 15 years of cooler batch sparging. It’s easier and faster and takes up less space, but mostly it seems a lot safer now that I have young kids. I recently bought a second never-used open box 2021-model foundry from someone slipping out of the hobby and have been thinking of the possibilities.

The biggest con for my about the foundry vs my old setup is the grain limit and ::much:: lower mash efficiency pretty much prevents me from brewing anything over 1.070. I still have my old system, though, so I figure I can always just brew a big beer the old fashioned way. Then I got an idea to BIAB with one of the brew bags they sell for the foundry and a hoist setup in my back patio. Could I partigyle with my dual foundries? Obviously I CAN do this, but I wonder what the upper limit of grain would be here. The max volume is 10.5 gallons, but I think keeping it under 10 would allow the (admittedly unnecessary) recirculating part to work better. I figure I could mash, hoist the grain out, slide the grain into my second foundry, give it a stir, and hoist it back out.

Does anyone have an easy calculation of what my realistic max grain limitation would be with 10 gallons, assuming I want enough water to end up with at least 6.5 gallons of sweet wort?

[CounterPressure]

I just purchased a used Brewzilla this past weekend but have yet to use it.  Having done some reading and watching videos, it seems people who use a brew bag inside the units (without the malt pipe) get a pretty considerable increase in efficiency due to the ability to crush finer without clogged pumps and stuck sparges.  at least one claim was 68% went to low 80s simply by using the bag and crushing finer (and recirculating).  Reading reviews on the brewinabag site, that seems about average. 

Mine came with a bag but I do not know if it was intended for use in the Brewzilla.  I inquired via email to the former owner but no response yet.  The bag is clean as new and doesn't look like it fits very well, so I suspect it might have been an early attempt to do BIAB with a kettle but never materialized for them. 

[skyler]

I suspect the bag could’ve been used for hops, too.

In any case, I did the math myself (realizing it wasn’t hard to look up the average displacement of malt is .08 gal/lb). It looks like I would absolutely max out at 20 lbs of grain, and that would probably require me to remove a couple gallons of water from the foundry first, then pour it back in (and accept that I might end up with less than 6.5 gallons of sweet wort). Seems like 18 lbs of grain is safer, but that is barely more than the 16 lbs i mash with now (though apparently efficiency will bump), so I will probably try it with 20 lbs and top off if I have to.

I’m thinking of doing an IPA or maybe a Belgian Golden Strong Ale with almost entirely base malt (and a touch of carafoam) and then adding some dark crystal and pale chocolate malt into the gyle to make a dark mild.

[CounterPressure]

Currently on page 6 of the reviews on biab,there's a guy with an Anvil who did a 19# batch in a bag.  He's got a photo, the thumbnail is not very good but open it up and look at it.  He says he's got 19# in there.  That looks like there isn't room for another tablespoon of water. The review is from 7/16/21
If 19 is in there, 19.01 is certainly the max.
And 19# is a BIG 5 gal batch...

https://www.brewinabag.com/products/all-in-one-anvil-grainfather-robo-brewers-unibrau?_pos=1&_sid=421b9e6b7&_ss=r&variant=39700378812476

[skyler]

19 lbs isn’t that much. Efficiency is low in this system for me ~60-65% compared to ~80% with my old system. And 5 gallons of IPA in my keg means 6.75-6 gallons of beer in the fermenter.
That means 19 lbs doesn’t even get me to 1.070 with a no-sparge.

[Richard]

Use the max amount of grain you can manage, then add extract to get your OG up to what you want.

[skyler]

I have no interest in adding extract to my beer

[rburrelli]

I have done 17 lb with @ 2qt/lb ratio. That was about an inch from the top of the unit.