Help with Mash Recirculation

[rzwahr]

I am using the Bayou Classic 62qt with steamer basket also. I recirc straight into the top of the mash using a chugger pump.

I have had what you describe happen on occasion, although i can catch it pretty fast due to the fact that I have a sight glass on the side of my kettle. When I see the liquid level dropping I can usually solve the issue by either stirring the mash or by backing off on the flow rate using the ball valve I have mounted on the outflow of the pump. When stirring, I have noticed that if I brush along the sides of the bag/basket as I am stirring that seems to have a pretty rapid impact, vs just stirring in the middle and scraping the bottom of the bag. I'm pretty sure my bag is just getting clogged with particulate.

I was doing some googling on it last night and came across this blog post, which sounds almost exactly like the problem I had been having.

I have reached out to Chad at arborfab.com as he recommended for a quote on a mod to the strainer basket. Same idea as what @schiersteinbrewing was referring to above, just using the upper "collar" of the strainer basket if you will. Here's a pic of what I am referring to, although this one looks quite a bit shorter than mine since the blogger was using the 10 gallon BC with steamer basket.

Depending on the cost, I may just elect to have a basket made without use of the collar of the existing steamer basket, as that may prove cost ineffective due to having to ship the steamer basket to him to modify. Might be cheaper to just have him make the basket from scratch.

Looks like Utah Biodiesel Supply does pretty much the same stuff, but since I am in NC it is cheaper to ship from Michigan (ArborFab) than from Utah.

My goal here is to increase flow rate through the grainbed to minimize stratification and to also be able to walk away from the thing without it ending up in disaster.

Currently, I use LocLine as a "sparge arm" to recirculate on top of the mash using just their standard kit and regular nozzles as seen in the first photo of my post. However, I just picked up their flow nozzle kit, which most folks are using as a circular pattern on top of the mash, as in this photo:

After thinking about it though, I believe what I am going to try is to make a COFI-type solution out of this, by straightening it and twisting the nozzles all the way down the length of it so I am getting a radial pattern all the way down. I would bulkhead the top of the line to the top of the kettle through the lid. Nice part about LocLine is you can add or remove segments as needed so if you had a lower liquid level on a given batch, you could simply modify the height of the spray portion so it stays under liquid, then use standard locline links to make up the difference between there and the exit from the kettle. Kind of like this:

I plan to play around with this on my next brew day and will report back the results. If that doesn't do anything or makes no difference, I can always adjust it back into the loop orientation as above and go from there.

**EDIT** - if you are interested in LocLine and want to learn more about it go to their website and check it out - most of these items can be found on Amazon. Here is a link to the spec page for the materials it is manufactured from (Standard Hose and Fittings), at the bottom it states that it is FDA food safe. Had someone PM me about that.

 

[newnick]

Very slick. I agree with you about just getting a new basket made. It would be cool if it would just fit into the kettle like the stock basket does. I like how the return enters the top portion of the pot in the drawing also. I return back through the lid with my setup, but coming back in through the top of the pot would make it easy to remove the lid any time you wanted while circulating. Using quick connects would make it easily removable. You would need a round hole in the bag where the line comes through so you could still overlap the top of the pot with the basket but that's not a big deal. Those locline nozzles are very cool too.

 

[wilserbrewer]

MIght this issue be caused by fines and flour accumulating on the top surface of the grain bed. I notice this both when I BIAB, and also when batch sparging in a cooler. Simply raking or disturbing the upper portion of the mash starts the flow again.

Perhaps using the lock line or another recirc feed down into the mash would help?

FWIW, the SS basket does allow an alternate flow path outside the basket to the bottom of the kettle, similar to a bag inside a strainer basket perhaps?

 

[rzwahr]

MIght this issue be caused by fines and flour accumulating on the top surface of the grain bed. I notice this both when I BIAB, and also when batch sparging in a cooler. Simply raking or disturbing the upper portion of the mash starts the flow again.

Great point. I'll have to give that a shot - never really considered maybe the issue lies at the top of the mash but it is quite possible. Thx for the tip!

 

[Snicklefritz]

I've had this same problem with my Brew Boss (non cofi) using wilser bags. Their are certain grain bills (or too fine a crush) that will contribute to the equivalent of a stuck sparge in the recirculating BIAB world. If I do anything weird with my mash, i.e. lots of wheat, pumpkin, corn meal (cream ale) or have a fine crush I will use the bag that came WITH the Brew Boss. This bag doesn't have as fine a weave as the wilser bags and so doesnt seem to ever have this issue. It does allow more sediment into the boil but that doesnt seem to cause any problems in my experience. I've actually contacted Darin (have i mentioned before he will answer ANY question you have?) about this as well and he said this is exactly why the system ships with the BIAB bags that it ships with, he tested a finer mesh and had the same problems with certain grain bills. Stirring every 10 minutes helps as well.

I will use my wilser bag 90% of the time and I've gotten to "just know" when ill need to use the original. When in doubt, I use the original bag. I've also thought of throwing some rice hulls in like you would in a traditional mash tun but havent tested that yet

 

[Bellybuster]

Just for interest, the bubble builds up on the coif filter too.
Next mash watch and see if it coenside with the element firing. The liquid very near to the element does create steam when the element is firing. The element is much hotter than the surrounding liquid.
I'm guessing the bubble is starving your pump as it has nowhere to go.
With the mesh filter, the bubble can release up the side.

 

[1MadScientist]

I assume you are doing a full volume BIAB mash, all water needed up front?

A standard crush of .039" is all that is needed.

There should be no need of a basket.

That said, I don't know what is going on, if the above is true, then might be the flow rate. It should be slow, about 10 litres per minute. What is your flow rate?

 

[schiersteinbrewing]

I assume you are doing a full volume BIAB mash, all water needed up front?

A standard crush of .039" is all that is needed.

There should be no need of a basket.

That said, I don't know what is going on, if the above is true, then might be the flow rate. It should be slow, about 10 litres per minute. What is your flow rate?

Yes full volume.

Crush was .030" opened the mill to .035" for the last batch, .040" is the next step. Ordered grains milled from Austin Homebrew for my brew this Saturday (a Ordinary Bitter), if their crush works better going to see if they will divulge their crush gap for me.

I have been adding rice hulls too.

I use the basket to keep the bag off the heating element in the kettle.

Flow rate is 2-3 liter/min, just enough to keep the wort moving and to reduce temperature stratification.

 

[blizz81]

It's weird, I wonder if it's something specific to electric / the Brew Boss setup, as I haven't run into problems on my not-really-BIAB-but-MIAB RIMS system. Or maybe a (wilser) bag in a keggle with the (in my case) bottom cut out and clipped around the top doesn't snug up quite as much to the sides as it does in a full open kettle. Or maybe running the return outside the bag makes that much of a difference, though I don't notice any more channeling doing it with the bag as I did without (a small indent in the very top of the grain bed by the loc-line), and the wort seems to circle around both inside the bag and out near the outlet just fine.

 

[schiersteinbrewing]

It also use to happen on my induction system using a BC basket as well. Then switched to a Jaybird false bottom and then it only happened when using rye or flaked grains.

 

[hafmpty]

I don't have a BrewBoss, but I do have a 400 micron basket that was made for me by Chad at Arbor Fab (P.S. he does all the work for Utah Biodiesel too). I BIAB in a 7.5gal Blichmann G2 Boilermaker while recirculating through the Blichmann Tower of Power Stand.

I know this goes against common BIAB lore...but if you're going to be recirculating, you're better off crushing A LOT coarser. I know...I know...in BIAB everyone says crush extra fine. Well, maybe when you're using a bag that's just sitting there. But when you're recirculating, you need a loose grain bed that allows the wort to flow easily and freely.

I have my mill set at .050...yes .050. That's a BIG gap for BIAB. But I can also recirculate through my system with the ball valves fully opened through 1/2" ID silicone tubing. My flow meter on the TOP only has markings up to 2.5gal per minute, but I'm way past that. I'm easily in the 3.5gal-4gal per minute range, if not more.

This kind of flow rate means I have ZERO temperature stratification. My mash temperatures are stable...everywhere...throughout the entire kettle. With 6gal of water in my kettle, at a flow rate of 3gal per minute, I'm sending all the wort past the temp sensor every 2 minutes. That's 30x over the course of the 60min mash that the entire volume of wort is running past that temp sensor. It's hard for a hot/cold spot to hide with that many temp readings.

Not only that, but I easily hit 80% efficiency with no sparge and NO SQUEEZING either. I just pull the basket and let it drip out.

But this is only possible by crushing loose. I learned this from my 3V system that was modeled after the Sabco system. I didn't believe it at first. I stuck to my guns with that system at first crushing around .035. I used rice hulls, throttled the flow, etc. But then I read the Sabco System Manual. In that they recommend a crush of .045-.060. Well...I went in the middle and literally overnight ended my flow-rate woes. And my efficiency went up dramatically...which the guys at Sabco said would happen.

I went from a consistent 72% to 88% efficiency. It doesn't makes sense that grain that was just "cracked/broken open" instead of "crushed" would give better efficiency, but it did.

So...for recirculating, I know my advice is probably going to fall on some deaf ears because "Use a tight crush...pulverize it to flour" is pretty much Gospel in the BIAB community...but try it. Loosen up your mill.

If you recirculate...loosen it up for one or two batches. Consider it an exBEERiment. Loosen your mill to .045 or .050 or...if you want to be crazy go with .065! See what happens. The amount of sticky flour will be less. The husks will function more like an actual filter. And because you can recirculate faster, you'll be running those enzymes past the grain like crazy allowing the to do their magic while at the same time maintaining consistent temperatures.

 

[Gavin C]

@hafmpty

That's really interesting and cool info. Thanks for that. This sounds mighty familiar to what @Kal talks about for his great 3 vessel setup. The rapid and easy flow of recirculating wort is the chief player not the milling.

I would imagine those numbers would be highly reproducible and consistency would be solid.

Nice.

 

[RM-MN]

I don't have a BrewBoss, but I do have a 400 micron basket that was made for me by Chad at Arbor Fab (P.S. he does all the work for Utah Biodiesel too). I BIAB in a 7.5gal Blichmann G2 Boilermaker while recirculating through the Blichmann Tower of Power Stand.

I know this goes against common BIAB lore...but if you're going to be recirculating, you're better off crushing A LOT coarser. I know...I know...in BIAB everyone says crush extra fine. Well, maybe when you're using a bag that's just sitting there. But when you're recirculating, you need a loose grain bed that allows the wort to flow easily and freely.

I have my mill set at .050...yes .050. That's a BIG gap for BIAB. But I can also recirculate through my system with the ball valves fully opened through 1/2" ID silicone tubing. My flow meter on the TOP only has markings up to 2.5gal per minute, but I'm way past that. I'm easily in the 3.5gal-4gal per minute range, if not more.

This kind of flow rate means I have ZERO temperature stratification. My mash temperatures are stable...everywhere...throughout the entire kettle. With 6gal of water in my kettle, at a flow rate of 3gal per minute, I'm sending all the wort past the temp sensor every 2 minutes. That's 30x over the course of the 60min mash that the entire volume of wort is running past that temp sensor. It's hard for a hot/cold spot to hide with that many temp readings.

Not only that, but I easily hit 80% efficiency with no sparge and NO SQUEEZING either. I just pull the basket and let it drip out.

But this is only possible by crushing loose. I learned this from my 3V system that was modeled after the Sabco system. I didn't believe it at first. I stuck to my guns with that system at first crushing around .035. I used rice hulls, throttled the flow, etc. But then I read the Sabco System Manual. In that they recommend a crush of .045-.060. Well...I went in the middle and literally overnight ended my flow-rate woes. And my efficiency went up dramatically...which the guys at Sabco said would happen.

I went from a consistent 72% to 88% efficiency. It doesn't makes sense that grain that was just "cracked/broken open" instead of "crushed" would give better efficiency, but it did.

So...for recirculating, I know my advice is probably going to fall on some deaf ears because "Use a tight crush...pulverize it to flour" is pretty much Gospel in the BIAB community...but try it. Loosen up your mill.

If you recirculate...loosen it up for one or two batches. Consider it an exBEERiment. Loosen your mill to .045 or .050 or...if you want to be crazy go with .065! See what happens. The amount of sticky flour will be less. The husks will function more like an actual filter. And because you can recirculate faster, you'll be running those enzymes past the grain like crazy allowing the to do their magic while at the same time maintaining consistent temperatures.

How long of a mash do you do to get the 80% efficiency from the coarsely crushed grains? From what I have gleaned from reading over the past few years is that you can get good efficiency from any crush if you can mash long enough and control the temperature during the entire time. I fairly often suggest longer mashes for people who get poor crush from their LHBS because that ups their efficiency.

By crushing finely, my mash converts fast so I don't need to control the temperature for very long. That makes for a very simple and cheap way to make the beer. Bring the water to strike temp, stir in the grains, wait 20 to 30 minutes and pull the bag out. Bam, 80% efficiency. Do a small sparge step and the efficiency goes to 85-90%.

 

[cantrell00]

I don't have a BrewBoss, but I do have a 400 micron basket that was made for me by Chad at Arbor Fab (P.S. he does all the work for Utah Biodiesel too). I BIAB in a 7.5gal Blichmann G2 Boilermaker while recirculating through the Blichmann Tower of Power Stand.

I know this goes against common BIAB lore...but if you're going to be recirculating, you're better off crushing A LOT coarser. I know...I know...in BIAB everyone says crush extra fine. Well, maybe when you're using a bag that's just sitting there. But when you're recirculating, you need a loose grain bed that allows the wort to flow easily and freely.

I have my mill set at .050...yes .050. That's a BIG gap for BIAB. But I can also recirculate through my system with the ball valves fully opened through 1/2" ID silicone tubing. My flow meter on the TOP only has markings up to 2.5gal per minute, but I'm way past that. I'm easily in the 3.5gal-4gal per minute range, if not more.

This kind of flow rate means I have ZERO temperature stratification. My mash temperatures are stable...everywhere...throughout the entire kettle. With 6gal of water in my kettle, at a flow rate of 3gal per minute, I'm sending all the wort past the temp sensor every 2 minutes. That's 30x over the course of the 60min mash that the entire volume of wort is running past that temp sensor. It's hard for a hot/cold spot to hide with that many temp readings.

Not only that, but I easily hit 80% efficiency with no sparge and NO SQUEEZING either. I just pull the basket and let it drip out.

But this is only possible by crushing loose. I learned this from my 3V system that was modeled after the Sabco system. I didn't believe it at first. I stuck to my guns with that system at first crushing around .035. I used rice hulls, throttled the flow, etc. But then I read the Sabco System Manual. In that they recommend a crush of .045-.060. Well...I went in the middle and literally overnight ended my flow-rate woes. And my efficiency went up dramatically...which the guys at Sabco said would happen.

I went from a consistent 72% to 88% efficiency. It doesn't makes sense that grain that was just "cracked/broken open" instead of "crushed" would give better efficiency, but it did.

So...for recirculating, I know my advice is probably going to fall on some deaf ears because "Use a tight crush...pulverize it to flour" is pretty much Gospel in the BIAB community...but try it. Loosen up your mill.

If you recirculate...loosen it up for one or two batches. Consider it an exBEERiment. Loosen your mill to .045 or .050 or...if you want to be crazy go with .065! See what happens. The amount of sticky flour will be less. The husks will function more like an actual filter. And because you can recirculate faster, you'll be running those enzymes past the grain like crazy allowing the to do their magic while at the same time maintaining consistent temperatures.

I use a corona mill so my setting is a lot less precise that a true malt mill.

That being said, anytime I use rice hulls, I see a bump in efficiency of 3-5%.

Your post explains why. I'm not nuts after all.

 

[TexasWine]

I don't have a BrewBoss, but I do have a 400 micron basket that was made for me by Chad at Arbor Fab (P.S. he does all the work for Utah Biodiesel too). I BIAB in a 7.5gal Blichmann G2 Boilermaker while recirculating through the Blichmann Tower of Power Stand.

I know this goes against common BIAB lore...but if you're going to be recirculating, you're better off crushing A LOT coarser. I know...I know...in BIAB everyone says crush extra fine. Well, maybe when you're using a bag that's just sitting there. But when you're recirculating, you need a loose grain bed that allows the wort to flow easily and freely.

I have my mill set at .050...yes .050. That's a BIG gap for BIAB. But I can also recirculate through my system with the ball valves fully opened through 1/2" ID silicone tubing. My flow meter on the TOP only has markings up to 2.5gal per minute, but I'm way past that. I'm easily in the 3.5gal-4gal per minute range, if not more.

This kind of flow rate means I have ZERO temperature stratification. My mash temperatures are stable...everywhere...throughout the entire kettle. With 6gal of water in my kettle, at a flow rate of 3gal per minute, I'm sending all the wort past the temp sensor every 2 minutes. That's 30x over the course of the 60min mash that the entire volume of wort is running past that temp sensor. It's hard for a hot/cold spot to hide with that many temp readings.

Not only that, but I easily hit 80% efficiency with no sparge and NO SQUEEZING either. I just pull the basket and let it drip out.

But this is only possible by crushing loose. I learned this from my 3V system that was modeled after the Sabco system. I didn't believe it at first. I stuck to my guns with that system at first crushing around .035. I used rice hulls, throttled the flow, etc. But then I read the Sabco System Manual. In that they recommend a crush of .045-.060. Well...I went in the middle and literally overnight ended my flow-rate woes. And my efficiency went up dramatically...which the guys at Sabco said would happen.

I went from a consistent 72% to 88% efficiency. It doesn't makes sense that grain that was just "cracked/broken open" instead of "crushed" would give better efficiency, but it did.

So...for recirculating, I know my advice is probably going to fall on some deaf ears because "Use a tight crush...pulverize it to flour" is pretty much Gospel in the BIAB community...but try it. Loosen up your mill.

If you recirculate...loosen it up for one or two batches. Consider it an exBEERiment. Loosen your mill to .045 or .050 or...if you want to be crazy go with .065! See what happens. The amount of sticky flour will be less. The husks will function more like an actual filter. And because you can recirculate faster, you'll be running those enzymes past the grain like crazy allowing the to do their magic while at the same time maintaining consistent temperatures.

Excellent info! @RM-MN asked the exact question I had while reading this. I started doing 30 minute mashes before I got my recirculating system and I just kept doing it when I made the switch. It has become a standard for me because it saves time, and it's logical. Why would I want to sit there, waiting on something to happen that was already done?

But, if I widen my gap from 0.025 to 0.050, how long will conversion take? I'll find a different solution if an hour long mash is required.

Another observation. A SS mesh basket has a couple of advantages compared to my system when it comes to restricting flow. One, the mesh of a 400 micron basket isn't as fine as a Wilserbrewer bag, and therefore doesn't restrict as much. Two, the only flow path for the wort through a steamer basket + voile bag combo is through the holes in the steamer basket. So not only does the bag itself cause more restriction, the total useful flow area through the bag is far, far less than that of the SS mesh basket.

I'm currently toying around with modifications to the basket to increase the open area. But maybe I'll ditch the entire basket and pull out the pizza screen false bottom and give it a whirl.

 

[hafmpty]

How long of a mash do you do to get the 80% efficiency from the coarsely crushed grains?

I mash for 60 minutes.

I fairly often suggest longer mashes for people who get poor crush from their LHBS because that ups their efficiency.

I can only speak for the RECIRCULATING mash. When I mashed in a Rubbermaid Drink Cooler, I crushed more fine...around the .036 area. But once I started recirculating, I crushed coarser.

By crushing finely, my mash converts fast so I don't need to control the temperature for very long. That makes for a very simple and cheap way to make the beer. Bring the water to strike temp, stir in the grains, wait 20 to 30 minutes and pull the bag out. Bam, 80% efficiency. Do a small sparge step and the efficiency goes to 85-90%.

Sounds like you've got your system figured out. That's awesome. I seem to be getting mine dialed in too. I was answering the question about recirculation though...not mash times/conversion (though they are related for sure). If you're not recirculating, I think a coarse crush is counter-productive.

But if you are recirculating...to maintain temperature stability and good flow rates, a coarser crush allows for that while (at least in my experience) still giving good efficiency and conversion.

...if I widen my gap from 0.025 to 0.050, how long will conversion take?

Good question. I've never tested this on my system. I'm brewing on 9/28. I'll set a few timers and see when conversion is complete. Could be a cool experiment. I've always done 60 or 90 minute mashes out of habit...and they've always converted. But I'll check on the next few batches to see what I find out.

A SS mesh basket has a couple of advantages compared to my system when it comes to restricting flow. One, the mesh of a 400 micron basket isn't as fine as a Wilserbrewer bag, and therefore doesn't restrict as much. Two, the only flow path for the wort through a steamer basket + voile bag combo is through the holes in the steamer basket. So not only does the bag itself cause more restriction, the total useful flow area through the bag is far, far less than that of the SS mesh basket.

You are right about the basket. That's part of the reason I bought it. With a bag, you have a very fine mesh. But again...why? Because BIAB is typically crushed very fine. But those bags, while fine, still allow a lot of wort through. So I don't think the bag is the issue.

I'm currently toying around with modifications to the basket to increase the open area. But maybe I'll ditch the entire basket and pull out the pizza screen false bottom and give it a whirl.

Sounds like a cool test to try. Change one thing...see how it works. If you like it...cool. If not...change one more thing and repeat this process until you get the results you want.

 

[RM-MN]

Excellent info! @RM-MN asked the exact question I had while reading this. I started doing 30 minute mashes before I got my recirculating system and I just kept doing it when I made the switch. It has become a standard for me because it saves time, and it's logical. Why would I want to sit there, waiting on something to happen that was already done?

But, if I widen my gap from 0.025 to 0.050, how long will conversion take? I'll find a different solution if an hour long mash is required.

Another observation. A SS mesh basket has a couple of advantages compared to my system when it comes to restricting flow. One, the mesh of a 400 micron basket isn't as fine as a Wilserbrewer bag, and therefore doesn't restrict as much. Two, the only flow path for the wort through a steamer basket + voile bag combo is through the holes in the steamer basket. So not only does the bag itself cause more restriction, the total useful flow area through the bag is far, far less than that of the SS mesh basket.

I'm currently toying around with modifications to the basket to increase the open area. But maybe I'll ditch the entire basket and pull out the pizza screen false bottom and give it a whirl.

Try shoving a couple long spoons down between the bag and steamer basket and see if that makes less restriction. The spoons should hold the bag away from the basket for at least a little distance from them.

 

[TexasWine]

Try shoving a couple long spoons down between the bag and steamer basket and see if that makes less restriction. The spoons should hold the bag away from the basket for at least a little distance from them.

Good idea. I ended up making a modification to my steamer basket. Used a Greenlee punch to make a diamond pattern, reeming out the factory small holes and making of larger holes. I ran out of time and didn't do the top row, but I think it'll still work. And no large holes in the bottom. I'm afraid of the bag touching the element.

View attachment 1442614021907.jpg

View attachment 1442614038135.jpg

View attachment 1442614047848.jpg

 

[hafmpty]

Good idea. I ended up making a modification to my steamer basket. Used a Greenlee punch to make a diamond pattern, reeming out the factory small holes and making of larger holes. I ran out of time and didn't do the top row, but I think it'll still work. And no large holes in the bottom. I'm afraid of the bag touching the element.

Nice job. Looks cool too. The punches are definitely the way to go vs. a drill.

 

[Gavin C]

Seriously neat work there Tex. very impressive.

Keep punching holes till you make the equivalent of a basket Menger sponge

 

[TexasWine]

Thanks fellas! Brewing this weekend. I'll let you know how it goes.

 

[1MadScientist]

Thanks hafmpty,

I recirculate with just a voile bag. I had no issues with a 0.039" gap, but am interested in increasing my gap. Here's why...

With a courser grind there is an advantage of not needing to stir any after the initial mash-in. A courser grind means a loose permeable mash bed and minimal stirring. I can walk away for 90 minutes and feel good about it.

This doc came from reading several probrewer.com disscussions boards and is what I am talking about here;

https://www.yumpu.com/en/document/v...e-efficiency-for-small-brewers-craft-brewers-

I think I will try 0.050" next.

MS

 

[hafmpty]

Thanks hafmpty,

I recirculate with just a voile bag. I had no issues with a 0.039" gap, but am interested in increasing my gap. Here's why...

With a courser grind there is an advantage of not needing to stir any after the initial mash-in. A courser grind means a loose permeable mash bed and minimal stirring. I can walk away for 90 minutes and feel good about it.

This doc came from reading several probrewer.com disscussions boards and is what I am talking about here;

https://www.yumpu.com/en/document/v...e-efficiency-for-small-brewers-craft-brewers-

I think I will try 0.050" next.

MS

Wow! That's a fascinating document. I'd love to hear the lecture that accompanied it. I know there are differences (significant differences) between the methods the brewers at Rock Bottom use vs. BIAB, but still pretty cool to see the differences only changing the crush can make in a brewery.

 

[TexasWine]

Thanks hafmpty,

I recirculate with just a voile bag. I had no issues with a 0.039" gap, but am interested in increasing my gap. Here's why...

With a courser grind there is an advantage of not needing to stir any after the initial mash-in. A courser grind means a loose permeable mash bed and minimal stirring. I can walk away for 90 minutes and feel good about it.

This doc came from reading several probrewer.com disscussions boards and is what I am talking about here;

https://www.yumpu.com/en/document/v...e-efficiency-for-small-brewers-craft-brewers-

I think I will try 0.050" next.

MS

Excellent read. Thanks for sharing.

Edit: this table might be useful for those that read this article. #14 sieve is a nominal opening of 0.0555 inches.

http://www.sigmaaldrich.com/chemist...chnical-library/particle-size-conversion.html

 

[schiersteinbrewing]

Okie I'm trying it, set the mill gap to .050 and ordered grains. Now just to find the space to ferment and time to brew next week.

 

[TexasWine]

Okie I'm trying it, set the mill gap to .050 and ordered grains. Now just to find the space to ferment and time to brew next week.

Well goodness. If you and @1MadScientist are both going for it, maybe I should too. It'd be interesting to have three data points. Will y'all do us a favor and measure your gravity as the mash progresses?

 

[Ozarks Mountain Brewery]

I recirculated for years and at times had the same issues as most here but found 3 solutions, first just pull your bag up "if indeed you use one" and if you can here a sucking sound thats good, it will release the pressure, just drop it down and it mixes up the grain for you better than stirring because it forces grain upward, second mill your grain larger than the standard bib gap and mash longer. I cut my ball valve down to half flow also milling with the bigger gap and mashing for 120 minutes I've never had a stuck recirculation since, remember its not a race as long as the grain is saturating and covered with wort and at some point making its way to the top your set

 

[schiersteinbrewing]

Well goodness. If you and @1MadScientist are both going for it, maybe I should too. It'd be interesting to have three data points. Will y'all do us a favor and measure your gravity as the mash progresses?

Most defiantly, never measured the gravity as the mash progressed. I'd like to know that data as well.

 

[hafmpty]

#14 sieve is a nominal opening of 0.0555 inches.

That's really interesting that it's .055. I might loosen my mill up a bit more even. But one thing at a time. First I'm going to monitor gravity and conversion every 10 minutes. Then I'll maybe make some changes to the mill gap.

This should be interesting once the data comes in. Cool stuff. Gotta love HBT!

 

[schiersteinbrewing]

View attachment ImageUploadedByHome Brew1442668548.782254.jpg My setup and flow rate.

It went off with out a hitch. No stirring, no bag lifting, no "pumping out".

Only things done differently were clipping the bag to the handles and using crushed grains from Austin Homebrew, instead of milling my self.


8lbs British Pale Malt
8oz crystal 120
4oz special B
8g RO water treated to water profile of Amber Balanced
5ml lactic Acid 88%
60min mash at 152deg with 15min mash out at 168deg

Mash PH 5.1 at room temp
42 min left in mash 5.4 brix
23 min left in mash 7 brix
10 min left in mash 7.2 brix
0 min left in mash 7.8 brix (start of mash out)
10 min left in mash out 8 brix
pre boil gravity 8 brix
pre boil volume 7gal

 

[TexasWine]

View attachment 304132 My setup and flow rate.

It went off with out a hitch. No stirring, no bag lifting, no "pumping out".

Only things done differently were clipping the bag to the handles and using crushed grains from Austin Homebrew, instead of milling my self.


8lbs British Pale Malt
8oz crystal 120
4oz special B
8g RO water treated to water profile of Amber Balanced
5ml lactic Acid 88%
60min mash at 152deg with 15min mash out at 168deg

Mash PH 5.1 at room temp
42 min left in mash 5.4 brix
23 min left in mash 7 brix
10 min left in mash 7.2 brix
0 min left in mash 7.8 brix (start of mash out)
10 min left in mash out 8 brix
pre boil gravity 8 brix
pre boil volume 7gal

That's great news! So maybe just by increasing the crush even more you're problems will be solved. Wonder what kind of gap setting they use at AHS. And how'd the rest of brew day go?

Also interesting, the brix numbers above look a little wonky, or at least not how I would have expected. 23 to 10 only saw a 0.2 increase. But 10 to 0 saw a 0.6 increase. I would expect a decay in rate of increase as time goes on. Where/how were the samples pulled? Any stirring involved?

 

[TexasWine]

Finished drilling out the last row of small holes on my steamer basket. Then pulled out the trusty solar powered calculator.

Factory holes were 0.5 inches in diameter. Replaced 64 of them with with 1.25 inch diameter holes. That's an increase of about 66 square inches, or the equivalent of 9 inch diameter opening!

That, combined with a little loser crush, should fix my sporadic issue. This weekend will be a good test. I've got a pretty large grain bill at over 15 pounds. I'll provide updates as things progress.

 

[schiersteinbrewing]

That's great news! So maybe just by increasing the crush even more you're problems will be solved. Wonder what kind of gap setting they use at AHS. And how'd the rest of brew day go?

Also interesting, the brix numbers above look a little wonky, or at least not how I would have expected. 23 to 10 only saw a 0.2 increase. But 10 to 0 saw a 0.6 increase. I would expect a decay in rate of increase as time goes on. Where/how were the samples pulled? Any stirring involved?

I emailed AHS to see if they would tell me.

Everything went perfectly, haven't had a brew day that easy/enjoyable in a long time. Ended up with 5.5gal of a 10 brix ordinary bitter in the fermenter (60 min boil).

The samples were from pulled from the pump return. No stirring.

 

[Ozarks Mountain Brewery]

always nice to be able to relax during a brew day, if anything congrats, thats the way its suppose to be

 

[schiersteinbrewing]

AHS replied:

"We regularly test our mills, and try to keep the gap as close as possible
to .039"."

 

[dunbruha]

I tried a coarser crush this weekend. I have a 10-gal e-kettle and use BIAB with re-circulation. I have only made small batches so far (3 gal), and I haven't seen any of the flow restriction problems reported in this thread (yet). But as folks in this thread were saying that a larger gap would give higher efficiency, I thought I would give it a try. I increased the gap from as tight as I could set it to 0.050". My mash efficiency has been right around 85%, but when I increased the crush, it dropped to 75% (60-minute mash). I didn't measure the conversion, so I don't know if longer mashing would have increased the efficiency, but it definitely was worse for the same length of time. I guess I will go back to the finer crush unless the flow becomes restricted.

 

[TexasWine]

I tried a coarser crush this weekend. I have a 10-gal e-kettle and use BIAB with re-circulation. I have only made small batches so far (3 gal), and I haven't seen any of the flow restriction problems reported in this thread (yet). But as folks in this thread were saying that a larger gap would give higher efficiency, I thought I would give it a try. I increased the gap from as tight as I could set it to 0.050". My mash efficiency has been right around 85%, but when I increased the crush, it dropped to 75% (60-minute mash). I didn't measure the conversion, so I don't know if longer mashing would have increased the efficiency, but it definitely was worse for the same length of time. I guess I will go back to the finer crush unless the flow becomes restricted.

I had the same experience yesterday. Missed my gravity and was about 10% lower in efficiency than normal, but with my usual 30 minute mash.

Don't have time to do a full recap if brew day right now, but will provide more details later.

 

[RM-MN]

I tried a coarser crush this weekend. I have a 10-gal e-kettle and use BIAB with re-circulation. I have only made small batches so far (3 gal), and I haven't seen any of the flow restriction problems reported in this thread (yet). But as folks in this thread were saying that a larger gap would give higher efficiency, I thought I would give it a try. I increased the gap from as tight as I could set it to 0.050". My mash efficiency has been right around 85%, but when I increased the crush, it dropped to 75% (60-minute mash). I didn't measure the conversion, so I don't know if longer mashing would have increased the efficiency, but it definitely was worse for the same length of time. I guess I will go back to the finer crush unless the flow becomes restricted.

Before you give up on the coarser crush, compare the flavor of this beer to one that you made with the finer crush and report the results. I'm curious about the final product.:rockin:

 

[RM-MN]

Good idea. I ended up making a modification to my steamer basket. Used a Greenlee punch to make a diamond pattern, reeming out the factory small holes and making of larger holes. I ran out of time and didn't do the top row, but I think it'll still work. And no large holes in the bottom. I'm afraid of the bag touching the element.

I was going for the cheap and easy way to test. It looks like you just went whole hog with your modification. BTW can I borrow your Greenlee punch for 10 minutes or so to modify my combine. It needs an access hole so I can grease one fitting.

 

[1MadScientist]

The link I attached showed the pros went from a 120 to a 90 minute mash with those mill gap changes, our mileage may vary at a homebrewer level. I am going to try like a .046" gap at 90 minutes.