Grain Mill Gap for Anvil Foundry Brewing

I will be brewing on an Anvil Foundry 10.5 gallon recirculating system soon. I have read about stuck sparges with this system. Wondering what grain mill gap people are using for this system? Currently I am using a BIAB bag with a 10 gallon kettle and milling with 2 roller Monster Mill set at 0.28 gap. I think this should work fine with the Anvil System? Any suggestions would be appreciated. I know some brewers are using a grain bag with this system.

I would have to measure, but I just tighten it down until a credit card stands straight. I got some pieces through and it would be nice to keep them from getting through.

I thought a credit card is about a 0.34 gap?

Maybe [emoji2377] someone years ago told me to do it, so I did and I’ve never changed my process. So you could probably be right.

Oops correction my Monster Mill gap = 0.32 inches.

It is hard to talk about mill gap and stuck sparge. Every mill is just a little bit different.

Whatever you do make sure that your rollers are square.

It is better to talk about % left is screen #14.

To get a similar crush, the gap will vary depending on what mill you have. Different crushes may also work better on different systems. I’d start at ~.038, and work from there if needed, making adjustments in .002" increments.

After a lot of trial and error, I went from .025" to .042" when switching from BIAB to my Digimash with recirculation. Don’t be afraid to use a coarser crush. Recirculation and better temperature control will usually make up the difference in efficiency.

Though not the same system as the OP, that’s what I did. I brewed, adjusted, brewed, adjusted, etc, etc and finally landed on 60 grams on top 40 grams fell thru. I get very predictable results brewday to brewday with this setting.

What kind of screen is that?

It’s a No 14 Standard Test Sieve.  There’s a photo of the sieves in this ppt presentation: https://www.craftbrewersconference.com/wp-content/uploads/ImprovingBrewhouseEfficiency-Havig.pdf  (beginning on slide 20 of 40)

You’re welcome to borrow my sieve if you want.

That’s an interesting presentation. I’m one of the bad breweries with 83-85% efficiency. :wink: But, I don’t want to change it.

Not that it would matter much for the efficiency differences in the slides, but when you have significant increase in efficiency your amber and darker beers get lighter colored. You have to add more dark grains to compensate or just ignore it. But, more dark grains can start to affect flavor. Of course, in the slide deck Rock Bottom was looking for consistency across the country. Leveling the efficiency would have helped that.

60 to 82% for 3 gallons of Amber Ale (both batches at 1053 SG) goes from 9.9 to 8.0 SRM.  I noticed such a change with the Picobrew which had low 60’s efficiency and when I moved back to my current BIAB.

See weight of grains in numerator of Morey equation.

MCU = (Weight of grain in lbs) * (Color of grain in degrees lovibond) / (volume in gallons)

SRM color = 1.4922 * (MCU ** 0.6859)

Consider using rice hulls when recircing on the Foundry.  Since it is designed taller and narrower than some other all in one brew systems, the grain bed tends to compact somewhat.  I just stir it every 10 minutes and have few problems, but I recirc very slowly - just over a trickle. I use a line loc halo, rather than the included perforated plate.  You can also get a brew bag liner, if you want to BIAB.

My mill gap is .040” on my Schmidling mill - measured with gap feelers.

I use a gap of 0.034" on my MM2, and I brew in the Foundry 10.5 using both the grain basket and a bag, along with semi-regular stirring of the mash in addition to recirculation. I have a set of feeler gauges that I use to set the gap, and I check it before every use of the mill.

If I’m doing an “average” gravity beer I’ll get around 68% “mash efficiency” (as reported by BeerSmith) with a typical 60 minute mash at 152 followed by rise to 168 for 10 minutes. I can bump up the efficiency by mashing a touch longer or doing a sparge with a half-gallon or full gallon of hot water (the latter is something I usually do for high gravity beers). So, I’ve been hitting 73 to 75% efficiency pretty regularly, and I’m satisfied with that.

With over a year on my Foundry now, I know the behavior of my system pretty well. So, I can adjust recipes and process to hit the results I want pretty consistently, which is a nice feeling!

That’s nice for offering to loan the sieve screen! I am familiar with sieves for from working with USDA as a soil conservationist. But I won’t trouble you with it. I ordered a brew bag for the Anvil Foundry unit and will use it. Thanks to everyone for responding to my post! I am planning on brewing with the Anvil Foundry in January 2022. Merry Christmas to y’all and happy brewing!