Have you ever used a BIAB bag in your mash tun as a filter so you can mill finer?

[KyBeer]

Just listened to Lorane Evens on a pod cast. She said she did this and mills at .029. I have done this one time when my mill was set too close. I might start doing this if the clean-up is easyer and BHE stays above 78%. If you use this methode do you still continious sparge?

 

[KyBeer]

Okay. MIAB in a MT. To make a braley wine that calls for a 28 pound grain bill what size MT do I need? Will 20 gallon work for batch sparge?

 

[doug293cz]

Okay. MIAB in a MT. To make a braley wine that calls for a 28 pound grain bill what size MT do I need? Will 20 gallon work for batch sparge?

With a large beer, your lauter (and therefore mash) efficiency is going to drop significantly. Targeting a 5.5 gal post-boil volume, 28 lb grain bill, 0.12 gal/lb grain absorption, 2 hour boil @ 1 gal/hr boil-off, 1.25 qt/lb mash thickness, single batch sparge, and 100% conversion efficiency, I get the following using my mash and lauter simulator:

Strike volume: 8.75 gal
Mash volume: 11.0 gal
Initial run-off SG: 1.095
Sparge volume: 2.11 gal
Sparge run-off SG: 1.067
Pre-boil volume: 7.5 gal
Pre-boil SG: 1.087
Lauter Efficiency: 66%
Post-boil volume: 5.5 gal
Post-boil SG (OG): 1.119

To compare to a more normal OG beer, let's compare to a 12 lb grain bill, 1 hour boil, mash thickness as needed for max lauter efficiency, and everything else the same as the example above.

Strike volume: 4.69 gal
Mash thickness: 1.56 qt/lb
Mash volume: 5,7 gal
Initial run-off SG: 1.079
Sparge volume: 3.25 gal
Sparge run-off SG: 1.0315
Pre-boil volume: 6.5 gal
Pre-boil SG: 1.055
Lauter Efficiency: 84%
Post-boil volume: 5.5 gal
Post-boil SG (OG): 1.065

So, the big grain bill drops your lauter efficiency from 84% to 66%. Not much you can do about that, unless you want to boil off lots more water (several gallons.) And all of this has nothing to do with the bag - it would be the same without it. You might be able to boost the lauter efficiency by doing a fly sparge, but we are only looking at an increase to about 67 - 70% (depending on how good your process is.) And finally, if your conversion efficiency is less than 100%, your mash efficiency will be less than the numbers above (mash efficiency = conversion efficiency * lauter efficiency.)

There is one thing you could do to improve things - if you are willing to add a couple steps to the process: squeeze the bag before and after sparging. Squeezing the bag to achieve a 0.06 gal/lb grain absorption rate would allow you to achieve the 1.119 OG using only 23.2 lb of grain, and your mash efficiency would increase to 80%

Brew on

 

[KyBeer]

My system has a HERMS coil in the HLT and I can do a continuous sparge. That is how I run the system on my Imperial IPAs. Efficiency is mid 70's. Thought I might increase the MT from 10 gallons to a 20 gallon or just keep both for small or large brews.

 

[Sammy86]

Just listened to Lorane Evens on a pod cast.

You know she works here right? Paging Dr. @Yooper

and its Lorena...or your majesty as i once called her the Queen of Homebrewing

 

[KyBeer]

Auto correct on this old PC can't even spell ACER right. I have a friend that spells her name Lorane and it auto corrects to the DB spelling.
Thanks for the spell correction.
Any way the podcast was great.
I will try the bag in my mash tun and mill finer. Got a clone of Bell's two heart planned as soon as a fermenter frees up.

 

[Sammy86]

Got a clone of Bell's two heart planned as soon as a fermenter frees up.

One of my favorite recipes! Mine didn't come out as good as the original but was tasty brew!

Good luck!

 

[KyBeer]

It's one of my standards that I brew about twice a year. I have a Mystic Mama clone. I tweaked the grain bill and hop schedule to my taste, switch the yeast to Imperial A-20 or WLP001. Even used US05 for a change. Now I'm building my water from DI.
After 30+ years of brewing and providing free labor at a micro brewery for a few months, I now know I know less than I thought I did when I started.

We have done so much with so little for so long, we now know we can do anything for ever with nothing at all.

Thanks

 

[doug293cz]

My system has a HERMS coil in the HLT and I can do a continuous sparge. That is how I run the system on my Imperial IPAs. Efficiency is mid 70's. Thought I might increase the MT from 10 gallons to a 20 gallon or just keep both for small or large brews.

Is that mid 70's mash efficiency using a continuous (fly) sparge? On what kind of OG range?

If we look back at the second example in my previous post, a continuous (fly) sparge should be yielding a lauter efficiency of 90 - 92%. If you are in fact typically getting mid 70's mash efficiency with ~12 lb grain bills, that would put your conversion efficiency somewhere around 0.75 / 0.9 (mash eff / lauter eff) = 83%, which is pretty low. If your typical mid 70's is with a single batch sparge, then your conversion efficiency would be around 0.75 / 0.84 = 89%, which is better, but not great.

With an 86% conversion efficiency (average above) and a lauter efficiency of 68% (for your 28lb grain bill) you would be looking at a mash efficiency of about 0.86 * 0.68 = ~58%.

Crushing finer, because the bag enables it, should improve your conversion efficiency, all else being equal. The finer grind may make recirculation during mashing a bit more challenging (slowing the recirc flow rate should help.)

Brew on

 

[dbayub]

I mash in a bag in a 20 gallon bottom draining mash tun. I mill very fine. After mashing, I hoist the bag (custom brew bag) and drain. Then I batch sparge, lift and drain again. No recirculation, no vorlauf.

Largest beer I do is an Imperial stout, 33lbs of grain, 11 gallons of strike water, mostly if not all first runnings, 1.14 OG. I use the second runnings for another beer.

 

[Yooper]

Just listened to Lorane Evens on a pod cast. She said she did this and mills at .029. I have done this one time when my mill was set too close. I might start doing this if the clean-up is easyer and BHE stays above 78%. If you use this methode do you still continious sparge?

I mix it up so often- often I'll do a no-sparge BIAB type of brew but still in my MLT. Sometimes I do a batch sparge and sometimes a fly sparge, depending on the size of the grainbill and the recipe (5.5 gallons vs 11 gallons) using the same equipment.

I LOVE my BIAB bags I got from @wilserbrewer. They are well made and wash in the washing machine. So even with a false bottom and a 3 vessel system, I use the bag. It makes clean up easier, and I haven't clogged my pump (I have a bottom draining MLT) not even once since getting the bags!

 

[Yooper]

Auto correct on this old PC can't even spell ACER right. I have a friend that spells her name Lorane and it auto corrects to the DB spelling.
Thanks for the spell correction.
Any way the podcast was great.
I will try the bag in my mash tun and mill finer. Got a clone of Bell's two heart planned as soon as a fermenter frees up.

Thanks for the kind words. With the bag, just ensure that the grain is still free flowing and well mixed in the liquid. Some brewers have jammed more grain into the bag for larger grainbills, but even though it's in a bag you want the grain to be very loose and easy to stir.