Single Vessel Brewing System Temperature Stability

[ScrewyBrewer]

My perfect BIAB system, if it were possible to design, would include a way to stir the mash while the lid is on and a way to return recirculated wort about two to four inches below its top layer. Of course, adding a Co2 post for increased LODO brewing would be a nice touch too.

 

[Mac MacFarlane]

Bobby I took your advice and added a tee and line going to my whirlpool port should help with flow and better temp stability.

 

[PINbeer]

Bought a Tee and a Tri-Clamp G2 Linear Flow Valve (blichmannengineering.com) to try to reduce temperature differences in my Spike Solo based on the discussion here. Glad that I did. However, one thing that's a bit of a pain is being able to set and maintain a consistent stream to the top of the basket. The volume of liquid directed to the top of the basket is very finicky and I have to adjust it frequently since it seems to drop off over time. More than once, I've put it at what seems like a good rate only to come back 5 mins later and there's no liquid coming through to the top at all. Before setting it up, it seemed that there would be enough pressure to force a consistent amount of liquid through the valve to the top and that the rest would go to recirc port. But, it's not working that way in real life. Anyone else have this issue when splitting between the 2 ports? Any better configuration that I can do to make the volume to the top of the basket more consistent?

 

[Bobby_M]

The issue you're having is that the linear flow valve is collecting grain particles and slowing the flow down as it clogs more and more*. Make sure you let the grain bed settle for about 5 minutes before running the pump and run the grain basket recirculation a little more wide open for the first 5 minutes to "vorlauf" the grain bits out before dialing that flow down again.

*if you're suspect of this concept, put a sieve over the grain and put the recirc hose into it when you have this flow stoppage. Open the valve more and watch the grain collect in the sieve.

 

[tennesseean_87]

I'm thinking I need to try this on my home-made eBIAB. I've been having issues with recirc being too slow, leading to lag, leading to more hot-spots. I think part of it may be mill/crush (corona type still, thinking of upgrading), and part of it may be probe placement, which is in the return stream at the top of the bag. It'll definitely swing several degrees, maybe up to 5, especially if I'm stepping, which leads to the element going nuts, which leads to hot spots, which leads to element shutting off completely, which leads to cold spots, ....

I'm thinking to get a 4way cross, and have input, one output for whirlpool, one for top recirc, and one for thermowell. I'd probably do ball valves at the whirlpool and pump ends of that hose. That would solve both the probe placement and higher flow rate issues at the same time without having to replumb it again down the road.

 

[Bad Bubba]

Since Bobby posted this I have switched to his method. I found having the probe in a tee at the pump suction was not working well so I had another port put in my kettle and purchased a longer probe. Now my probe is a few inches from the element with the whirlpool keeping it well mixed. I have about a 2 degree F temperature drop between the kettle temp and the recirculating stream discharge point at the top. I cannot say my beer is better but I am more comfortable with the temperature control.

 

[adpostel]

Hey Bobby, first of all, thank you for all of your contributions, be it equipment, designs and research to our community. It's people like you that keep me brewing beer!

So I have a question for my AIO BIAB setup. I have managed to cobble together quite a few of your pieces and I have a 10 Gallon Brew Built E-Kettle with a 5500w element on a Auber EZ Boil PID setup with your BIAB False Bottom and a Spin Cycle whirlpool arm. I currently use a SS Brewtech InfuSsion Recirculation/Sparge Kit for recirc during the mash. My question is if I split up the recirc to go to the whirlpool arm, would there be an issue returning the hot wort to just that one single spot up against the grain bag and the kettle wall? It would seem to me that it would create a "hot spot" in that one area vs. going from the top of the grain bed down and through it. I just want to be sure I am not missing something, as I have followed all of your avice and the experiences of members here to come up with my system.

I built my system to be versatile, I can do a two vessel system with a 10 gallon mash tun cooler and use a grant to collect wort and pump it back into the boil kettle... or I can do BIAB in the boil kettle using your false bottom and recirc with my sparge setup. I am definitely gonna order some reflectix insullation to insulate my kettle when doing BIAB to help keep stable temps. The reason I chose to build a versatile system is to be able to do step mashes with the BIAB setup, as I currently don't have a way to do it in the cooler mash tun. Any thoughts or advice is greatly appreciated.

Adolph Postel
Seabrook, TX

I want to backtrack just a bit here and just make it clear that the point of this "talk" is not to suggest that you can't make very good beer with a much more lo-fi configuration. In fact, your temps would have to be wildly out of whack for it to fail to make wort. Where the "close enough" control starts to break down is when your wort is not hitting your desired FG either high or low, troubleshooting is impossible because you can't answer the question "what was your mash temp?" with precision.

That said, many people are happy with making good beer and consistency, repeatability and recipe communication is not all that important. I cover this caveat in the "Does It Matter" slide.

Another approach is to say: IF you use an electric kettle AND you use a pump, this is the best way to get the most out of that system.

If you're running a lo-fi BIAB wrapped in a blanket or whatever it means to you and the beer is good, this is not for you. It's especially not for you if you're still not controlling your fermentation temps or using closed transfers to kegs. There are a lot bigger fish to fry.

 

[CleanEmUpIves]

My question is if I split up the recirc to go to the whirlpool arm, would there be an issue returning the hot wort to just that one single spot up against the grain bag and the kettle wall? It would seem to me that it would create a "hot spot" in that one area vs. going from the top of the grain bed down and through it

The whirlpool arm should push wort around the pot instead of into the bag. If the bag covers the whirlpool arm then you might consider adding a port below your BIAB false bottom.

 

[doug293cz]

The whirlpool arm should push wort around the pot instead of into the bag. If the bag covers the whirlpool arm then you might consider adding a port below your BIAB false bottom.

Whirlpooling under the FB will not be effective for adding heat to the grain bed. Best for that is flow from top to bottom of grain bed (unless you have one of those systems that can to up-flow.)

Brew on

 

[Bobby_M]

My question is if I split up the recirc to go to the whirlpool arm, would there be an issue returning the hot wort to just that one single spot up against the grain bag and the kettle wall? It would seem to me that it would create a "hot spot" in that one area vs. going from the top of the grain bed down and through it. I just want to be sure I am not missing something, as I have followed all of your advice and the experiences of members here to come up with my system.

When I use locline to send the recirculated mash liquor to the top of the grainbed, it's positioned so the outflow is parallel to the top of the grain, just barely submerged in the liquid later above the grain. It's also positioned such that it causes the liquid to swirl around distributing the heat across the whole top. When I'm running a ramp up in temp for step mashing, it is true that the spot directly in the outflow is about 1-2F hotter than anywhere else in the top layer but that's still a very small deviation during the ramp times.

Somewhat related, if you have the type of system size:batch size that exposes damp agrain rather than fully submerged in liquid, that's about that only time a more distributed return method would be advantageous though I think it's by nature a less efficient system.

The whirlpool arm should push wort around the pot instead of into the bag. If the bag covers the whirlpool arm then you might consider adding a port below your BIAB false bottom.

It's actually both. The point of the thread is that the ideal temp stability is achieved by whirlpooling both above and below the bag/grain bed.

 

[CleanEmUpIves]

Whirlpooling under the FB will not be effective for adding heat to the grain bed. Best for that is flow from top to bottom of grain bed (unless you have one of those systems that can to up-flow.)

Brew on

If your BIAB has a V shape to it and the outlet is too high lowering the port would help.

 

[CleanEmUpIves]

It's actually both. The point of the thread is that the ideal temp stability is achieved by whirlpooling both above and below the bag/grain bed.

Right. I'm simply advocating to lower the whirlpool port if it's blocked by the BIAB.

 

[Bobby_M]

Right. I'm simply advocating to lower the whirlpool port if it's blocked by the BIAB.

I see what you're saying. He wasn't perfectly clear about where his current whirlpool lets out. I agree that the whirlpool needs to induce a whirlpool in the area below and/or on the sides of the grain containment area in addition to recirc up over the top.

 

[k-daddy]

I just fabricated this addition to the recirculation portion of my BIAB system based on the Breweasy Compact "direct deposit recirculation" system (photo attached). The 3/8" ID Pex tubing extends down to the false bottom and has a total of 14, 5/64" holes (4 holes opposed and 3 holes opposed). I slipped on a section of 1/2" ID tubing so I can cover the uppermost holes to avoid splashing when I sometimes remove 2 gallons of heated strike water for sparging. I did a dry run with water and found that I need to pump nearly 2L/minute in order for fluid to push through the upper 2-4 holes. I have had occasional suction issues when pushing this flow rate with my original recirculation feed just below the surface of the mash (photo attached). I'm wondering if this new delivery system will cause the same issue or perhaps the jettisoned wort through the holes will keep the grains loose and moving, allowing for better down flow through the grain bag. I could certainly drill a new piece with fewer holes but they'd be spaced further apart. Not certain if this new recirculation process will yield any significant improvement in temperature consistency, or make any difference in the final product, but tweaking for me is another enjoyable part of this hobby. Anyone using this method who might have some good intel? Thanks!

 

[brewbama]

@Bobby_M — I operate an SS Brewtech Infussion Mash/Lauter Tun. I recirculate by drawing from the lower drain port, thru a pump, thru a HERMS, return into the MLT thru the top return port, and the recirculating manifold under a mash cap and below the wort surface. My heat source is external to the MLT. Based on your data, would there be any advantage for me to split this return to two manifolds, one several inches below the other?

 

[Bobby_M]

@Bobby_M — I operate an SS Brewtech Infussion Mash/Lauter Tun. I recirculate by drawing from the lower drain port, thru a pump, thru a HERMS, return into the MLT thru the top return port, and the recirculating manifold under a mash cap and below the wort surface. My heat source is external to the MLT. Based on your data, would there be any advantage for me to split this return to two manifolds, one several inches below the other?

No, the split system is only advantageous when the heating is in the mash tun below the grain bag.

 

[ScrewyBrewer]

For what it is worth. My (circa 2014) High Gravity BIAB system circulates wort from the bottom and returns it to the top of the grain bed through a nozzle in the center of the lid. Over the years, after trying various methods to improve mash temperature consistency, I found nothing works better than frequent stirring using a large whisk.

 

[Wagon_6]

Bought a Tee and a Tri-Clamp G2 Linear Flow Valve (blichmannengineering.com) to try to reduce temperature differences in my Spike Solo based on the discussion here. Glad that I did. However, one thing that's a bit of a pain is being able to set and maintain a consistent stream to the top of the basket. The volume of liquid directed to the top of the basket is very finicky and I have to adjust it frequently since it seems to drop off over time. More than once, I've put it at what seems like a good rate only to come back 5 mins later and there's no liquid coming through to the top at all. Before setting it up, it seemed that there would be enough pressure to force a consistent amount of liquid through the valve to the top and that the rest would go to recirc port. But, it's not working that way in real life. Anyone else have this issue when splitting between the 2 ports? Any better configuration that I can do to make the volume to the top of the basket more consistent?

I like this setup for the solo. The tee and linear valve stays with the lifted basket and I’m guessing one could drain the hoses via the spike pump priming feature. Then move the hoses for a whirlpool. Has it been working better after letting the grain bed settle?

 

[MikeCo]

Does the temperature probe need to be below the false bottom to work in your setup, Bobby? Would it work if it was up higher in the kettle adjacent to the bag? I have a kettle with a BoilCoil and it would be easier to place the probe just above the coil. Rather than using a false bottom, I would suspend the bag a couple inches above the bottom by holding it on the top of the kettle with clamps.

 

[doug293cz]

Does the temperature probe need to be below the false bottom to work in your setup, Bobby? Would it work if it was up higher in the kettle adjacent to the bag? I have a kettle with a BoilCoil and it would be easier to place the probe just above the coil. Rather than using a false bottom, I would suspend the bag a couple inches above the bottom by holding it on the top of the kettle with clamps.

In my opinion, your plan will not work very well. For control stability, you want the controlling temp sensor placed as close as you can get it to the hottest wort in the system. The hottest wort is at the surface of the heating element. If you are recirculating, you want the temp sensor in the wort flow field downstream of the heating element, not upstream. The goal is to sense an increase in wort temp as soon as possible, so that the controller can modulate power before the wort overheats locally. Local overheating leads to system wide temperature instability, and can denature your enzymes (leading to poor conversion efficiency or poor wort fermentability.)

A suspended bag is also not recommended, as it tends to compress the grain mass, which is undesirable for the kinetics of mashing. You want the grain "swimming" as freely as possible in the wort during the mash.

Brew on

 

[odie]

I place my temp probe in the bottom of my basket. It sits directly above the element, less than an inch away. My recirc is a small fountain pump so the flow is slower than those big "brew" pumps, but steady.

The "flow" is basically sideways underneath the basket towards the spigot.

I would say once it come up to temperature it's pretty stable through the entire kettle and mash.

 

[MikeCo]

I place my temp probe in the bottom of my basket. It sits directly above the element, less than an inch away.

Interesting method. What type of basket and heating element do you have, and do you use a bag? Do you mean you just place the probe directly into the basket from the top of the kettle with no hole drilled in the kettle?

 

[odie]

I have an approximately 15 gal olive oil barrel with a spigot that is my kettle. I use a SS 120v water heater element. I drilled a side hole to mount the element.

I found a steamer basket that just barley slips inside so the side gap is practically nothing. I actually had to file the basket rim down to get it to slide in. And I've closed the sides of the basket so all flow must go down and out.

I place a wilser bag inside the basket. I place the temp controller probe in the center bottom of the basket then bag on top with the grain. The basket slides into the kettle and stops about 3/4 inch above the element since it rests on the bung for the dial thermometer I installed. The basket cannot actually touch the element.

here are some random pics I have on the computer. It doesn't show everything but will give you an idea of how I'm set up.

not pictured is my recirc pump. but it's just a simple 12v magnetic fountain pump, high temp rated, that just take wort from the bottom spigot and pumps it on top of the grain bed...for hours while I'm away. temps are pretty even top to bottom I think.

 

[MikeCo]

I have an approximately 15 gal olive oil barrel with a spigot that is my kettle. I use a SS 120v water heater element. I drilled a side hole to mount the element.

I found a steamer basket that just barley slips inside so the side gap is practically nothing. I actually had to file the basket rim down to get it to slide in. And I've closed the sides of the basket so all flow must go down and out.

I place a wilser bag inside the basket. I place the temp controller probe in the center bottom of the basket then bag on top with the grain. The basket slides into the kettle and stops about 3/4 inch above the element since it rests on the bung for the dial thermometer I installed. The basket cannot actually touch the element.

here are some random pics I have on the computer. It doesn't show everything but will give you an idea of how I'm set up.

not pictured is my recirc pump. but it's just a simple 12v magnetic fountain pump, high temp rated, that just take wort from the bottom spigot and pumps it on top of the grain bed...for hours while I'm away. temps are pretty even top to bottom I think.

View attachment 816465View attachment 816466View attachment 816467

Thanks for the explanation. Great DIY.

 

[bagbrewer]

I'm looking at some system upgrades that follow @Bobby_M 's design using his TC lid mounted adjustable mash return arm and a 1/2" NPT wye fitting from McMaster-Carr and 2 ball valves to split the flow to a whirlpool port and the recirculation arm in the lid. Two questions:
1. I don't have a pump at the moment and am leaning towards the Spike Flow but haven't seen much in the way of reviews outside of Spikes own site. Does anyone have any experience with this pump they care to share?

2. I normally do small batch (2.5-3 gallon) sizes so I'm wondering if there is any disadvantage to having the whirlpool port near the bottom of the kettle vs higher up when I get the urge to brew a 5 gallon batch?

I know I'm mixing NPT into a mostly TC system but I wasn't sure how much a 1.5" wye would affect the wort return through either the whirlpool or lid returns given its diameter vs a 1/2" fitting nor was I sure how a TC butterfly valve was at fine adjustments for flow control. I considered NPT all around using the G2 linear flow valves as they seem much easier to breakdown compared to a 3 piece valve but I've always found wrapping threads in pipe tape annoying. Granted its not hard but just one of those things I'd like to not have to do.

 

[passedpawn]

The SS Brewtech SVBS all-in-one allows this split return, exactly as described in Bobby's post. I just bought one and I have been using it a lot

 

[Brooothru]

The SS Brewtech SVBS all-in-one allows this split return, exactly as described in Bobby's post. I just bought one and I have been using it a lot

I’m officially jealous now. Too bad my 12 year old 20L Braumeister is still going strong. I paid almost a grand more than that SSBT all-in-one for my setup, plus the modifications I’ve made still don’t have all the features and flexibility of the SS Brewtech. Twelve gallon capacity is much more than I need, however. But it sure looks sweet.

 

[k-daddy]

I'm looking at some system upgrades that follow @Bobby_M 's design using his TC lid mounted adjustable mash return arm and a 1/2" NPT wye fitting from McMaster-Carr and 2 ball valves to split the flow to a whirlpool port and the recirculation arm in the lid. Two questions:
1. I don't have a pump at the moment and am leaning towards the Spike Flow but haven't seen much in the way of reviews outside of Spikes own site. Does anyone have any experience with this pump they care to share?

2. I normally do small batch (2.5-3 gallon) sizes so I'm wondering if there is any disadvantage to having the whirlpool port near the bottom of the kettle vs higher up when I get the urge to brew a 5 gallon batch?

I know I'm mixing NPT into a mostly TC system but I wasn't sure how much a 1.5" wye would affect the wort return through either the whirlpool or lid returns given its diameter vs a 1/2" fitting nor was I sure how a TC butterfly valve was at fine adjustments for flow control. I considered NPT all around using the G2 linear flow valves as they seem much easier to breakdown compared to a 3 piece valve but I've always found wrapping threads in pipe tape annoying. Granted its not hard but just one of those things I'd like to not have to do.

I had 2 Blichmann Riptides with my previous 2 vessel KRIMS system but have since built a single vessel BIAB setup based on the Brewhardware design. I use a Topsflo pump like the one in Bobby’s video (he also sells them). It works perfectly and is lightweight and compact in size. I also use it for hop recirculation with a direct QD connection to the fermenter and never had a clogging issue. I would definitely add it to your list of considerations.

The whirlpool on my setup (10 gallon) is below the false bottom and, along with the Topsflo pump, it creates a strong enough current no matter the size batch.

I have all NPT, ball valves and QD’s on the hot side except for the TC heating element and kettle lid ports. Never really felt that sanitary TC fittings were necessary on the hot side and assembly is a cinch. Good luck.

 

[Bobby_M]

Agree. The Riptide and Flow are both more pump than you really need for batches smaller than 10 unless you were planning to CIP a fermenter using a spray ball. If you have all TC, you can easily split the flow with a TC tee. Theoretically, a wye performs better but that's assuming you needed maximum flow to both outputs but that's not even close to reality.

There's no problem with the whirlpool down low. If it was, I wouldn't use a low return on my own setup.

Bobby

 

[k-daddy]

Occasionally, I use the Topsflo pump and a Spike spray ball to rid the kettle of beer stone. It provides more than enough pressure to spin the spray ball, especially if I throttle back the whirlpool valve.

 

[bagbrewer]

I had 2 Blichmann Riptides with my previous 2 vessel KRIMS system but have since built a single vessel BIAB setup based on the Brewhardware design. I use a Topsflo pump like the one in Bobby’s video (he also sells them). It works perfectly and is lightweight and compact in size. I also use it for hop recirculation with a direct QD connection to the fermenter and never had a clogging issue. I would definitely add it to your list of considerations.

The whirlpool on my setup (10 gallon) is below the false bottom and, along with the Topsflo pump, it creates a strong enough current no matter the size batch.

I have all NPT, ball valves and QD’s on the hot side except for the TC heating element and kettle lid ports. Never really felt that sanitary TC fittings were necessary on the hot side and assembly is a cinch. Good luck.

Appreciate you sharing your experience. I was originally looking at the Riptide but based on what I read the flow control provided wasn't great at regulating flow for mash recirculation. Certainly not dead set on the Spike Flow either and actually originally was looking at the MK II from Kegland but it didn't seem to give enough of a whirlpool to get a trub cone although again I have no first hand experience with it either. I'll definitely add the Topsflo to the list.

 

[bagbrewer]

Agree. The Riptide and Flow are both more pump than you really need for batches smaller than 10 unless you were planning to CIP a fermenter using a spray ball. If you have all TC, you can easily split the flow with a TC tee. Theoretically, a wye performs better but that's assuming you needed maximum flow to both outputs but that's not even close to reality.

There's no problem with the whirlpool down low. If it was, I wouldn't use a low return on my own setup.

Bobby

No CIP for me, I can reach my arm down into all my fermenters to clean everything. Glad to hear you haven't seen any issues with a low whirlpool port. I assumed you would have altered your design if that were the case but I'd rather ask the question. My only other thought for switching to full on TC is being able to assemble/disassemble without any tools. So more of a convenience thing than any desire to try to make the hot side more sanitary.

 

[PINbeer]

I like this setup for the solo. The tee and linear valve stays with the lifted basket and I’m guessing one could drain the hoses via the spike pump priming feature. Then move the hoses for a whirlpool. Has it been working better after letting the grain bed settle?

Hey, sorry, missed this question. Yes, the tee stays with the basket. When you lift the basket, the hoses drain a bit anyway. I just drain them further using gravity (tipping them downwards) when I reconfigure the hoses for the boil. I just stick a small measuring cup underneath and sometimes pour that liquid back into the pot for the boil - though it's not much so sometimes I don't bother.

Re letting the grain bed settle... I assume you mean letting the grain absorb liquid for 10 mins prior to starting the pump. If so, then yes, it's improved significantly. That said, the variability of the flow from the valve attached to the basket means that I have to watch it regularly to make sure it's got enough flow. Seems like a couple of times during the mash I end up having to turn the valve much more open to clear it. I then turn it back down again to avoid putting too much liquid up top. If I don't open it wider periodically, it'll slow or stop completely. It's just a bit of a pain to constantly fiddle with it to get the right balance. I may try to see if there's a different valve I could use that's less prone to getting grain caught and interfering with the flow. But in the meantime, it's not too big of an issue and I think you should never be more than 5 mins away from your kettle with the element and pump on anyway, so it forces me to monitor it regularly.

 

[Bart Taylor]

Ok, this may be a stupid question but is there any reason you couldn't use a sight glass setup to preform this recirc function. Specifically where the bottom of the sight glass was mounted on a tee and the top portion was plumbed into the top of a kettle for a return?

 

[Red over White]

Ok, this may be a stupid question but is there any reason you couldn't use a sight glass setup to preform this recirc function. Specifically where the bottom of the sight glass was mounted on a tee and the top portion was plumbed into the top of a kettle for a return?

I don't see why you couldn't. I do like using my sight glass plumbed under the false bottom to show me how compacted my mash bed is.

 

[Bobby_M]

Ok, this may be a stupid question but is there any reason you couldn't use a sight glass setup to preform this recirc function. Specifically where the bottom of the sight glass was mounted on a tee and the top portion was plumbed into the top of a kettle for a return?

The sightglass wouldn't function as it's intended function in that case and would just be part of your plumbing system. You'd see the wort clarity as a small bonus, but I'd rather have a functioning sightglass to see if you're getting suction under the bag.

 

[Bart Taylor]

The sightglass wouldn't function as it's intended function in that case and would just be part of your plumbing system. You'd see the wort clarity as a small bonus, but I'd rather have a functioning sightglass to see if you're getting suction under the bag.

Ok, that was not even on my list of concerns. I will be adding a sight glass. I just really like them for ease of measurement and precision (which I know has little to due with accuracy). I'm firmly in the camp of "I'm not sure how important temperature stability is for me". But since I'm getting ready to add a sight glass I thought I would give it some consideration. So I reviewed a bunch of recirc setups for ideas and most I saw did not have a sight glass.

How important do you think having a functioning sight glass during recirc is?

 

[passedpawn]

Ok, that was not even on my list of concerns. I will be adding a sight glass. I just really like them for ease of measurement and precision (which I know has little to due with accuracy). I'm firmly in the camp of "I'm not sure how important temperature stability is for me". But since I'm getting ready to add a sight glass I thought I would give it some consideration. So I reviewed a bunch of recirc setups for ideas and most I saw did not have a sight glass.

How important do you think having a functioning sight glass during recirc is?

The SS Brewtech mash tuns have TWO sight glasses. One is ported above the false bottom that supports the grain bed. The other is below. Before recirc, those sight glasses show the same level.

During recirc, the difference between the two sight glasses illustrate the pressure differential, and absolutely indicate where a stuck sparge is happening. I find it very useful.

That might not be the question you were asking, sorry.

 

[Bart Taylor]

The SS Brewtech mash tuns have TWO sight glasses. One is ported above the false bottom that supports the grain bed. The other is below. Before recirc, those sight glasses show the same level.

During recirc, the difference between the two sight glasses illustrate the pressure differential, and absolutely indicate where a stuck sparge is happening. I find it very useful.

That might not be the question you were asking, sorry.

Its a data point but I brew in a single vessel so not an equivalent. BTW I looked at a SS mashtun and it had no sight glasses. I've never considered a sight glass important rather its a convenience thing. What do you do when you observe a significant differential?

 

[passedpawn]

Its a data point but I brew in a single vessel so not an equivalent. BTW I looked at a SS mashtun and it had no sight glasses. I've never considered a sight glass important rather its a convenience thing. What do you do when you observe a significant differential?

I'm not trying to convince you of anything. If you don't think a sight glass is important, great.

I've always had them for (obviously) measuring levels. But in the case of the mash tun, it was VERY useful (especially the one BELOW the false bottom). When I detected the differential in the mash tun sight glasses, I stirred the grains, which typically bought me some time, or solved the problem.

My mash tun. In left image, note the two sight glasses.