HERMS better than direct-fired recirculating MLT?

[betaman]

Augie, are you taking a temp reading for your dry grains? It’s very important to know your dry grain temp to accurately add the correct temp strike water as that’s where the majority of the temp equalization should occur not while mashing for reasons Augie mentioned.

 

[beernutz]

I have a natural gas-fired HERMS system, #1 in your list. In the 4 years I've used the system my pilot light has never gone out. Not sure what you mean by high cost - high cost relative to what? If you mean the cost of propane then nevermind but the cost of natural gas to use my system is not a lot.

There are no heating elements in a gas fired system - you use burners.

I'm looking into building a brewstand and I'm considering various options:
1. HERMS gas-fired
2. HERMS electric
3. Direct-fired gas recirculating MLT

1. Has some issues with keeping pilots lit with solenoid operated valves controlled by a PIDS box. Cost is fairly high with safety elements. Requires the HLT and BK to be drilled for the heating element.

2. This system is interesting from a control standpoint. There are no pilots to deal with but requires a lot of power (220V, 50A). Also, requires drilling of the HLT and BK. I would need to add this output to my garage.

3. I'm not sure if anyone has suggested this option, but I see this as a variant on the HERMS method. I would pump the wort around the MLT like in a HERMS system, but not a have a coil for the heat transfer. The MLT would be directly fired. This gives the advantage of keeping the wort clear and the temperature even like in a HERMS system. I don't need a coil which saves costs. I could manually control the MLT temperature like I do now and add a PIDS box in the future.

What do you think?

 

[augiedoggy]

Augie, are you taking a temp reading for your dry grains? It’s very important to know your dry grain temp to accurately add the correct temp strike water as that’s where the majority of the temp equalization should occur not while mashing for reasons Augie mentioned.

yes those temps are accounted for, it completely does not work when underletting for reasons I meantioned and beersmith calculations for this while accurate on my home system are way off on the 3bble setup, part of that is the amount of stirring and time it takes to dump all that grain in and mash in. That said I have learned to use them on a curve.. I have also learned that without good recirculation the temps in the mash tun start dropping , especially near the kettle walls immediately.

 

[betaman]

yes those temps are accounted for, it completely does not work when underletting for reasons I meantioned and beersmith calculations for this while accurate on my home system are way off on the 3bble setup, that said I have learned to use them on a curve.. I have also learned that without good recirculation the temps in the mash tun start dropping , especially near the kettle walls immediately.

3bbl is quite impressive are you pro now? Why do you think you get such a variation in mash temps? What is your evaporation rate in your BK, and how are you controlling your boil efficiencies? I am achieving an overall 80%. Not great but I think better than average.

 

[betaman]

3bbl is quite impressive are you pro now? Why do you think you get such a variation in mash temps? What is your evaporation rate in your BK, and how are you controlling your boil efficiencies? I am achieving an overall 80%. Not great but I think better than average.

Augie do you recirc while underletting? I stir.

 

[Blazinlow86]

I used 2 thermometers for the longest time, the first was an analog placed in the centre of the mash and the second a PID in lowest portion of the grain bed and found that with recirculating a direct fire MLT, the temp difference was negligible and closer to no difference nearing the 60 minute mark. No need for inline thermometer in my system. Oh, my MT is a stainless steel keggle and a Jaybird FB.

I don't use any thermometers/probes on my MLT as it matches whatever I have my HLT set too. When I first built the system I had a mechanic thermo on the MLT output and did have issues until I adjusted my grist to allow fast enough turnover without compacting the grain bed or causing channeling. If you prefer milling tight to attempt better efficiency you may need to use a probe in the hlt and compensate for the differential. Cheers

 

[Spyderbyte07]

That said, I do believe a hex-based herms is pretty easy to operate with pretty much zero risk of scorching anything...

Cheers!

That’s my plan- two vessels, two pumps, a counterflow chiller and an STC or inkbird. Mash in and start recirculating through the chiller. Monitor temperature as it returns to the MLT, and when it drops turn on the second pump to recirculate from the HLT through the outside of the chiller. As long as I keep the HLT above my desired mash temperature I won’t need any sort of precise control over it. This means I could heat my strike and sparge water together in the HLT and underlet the mash, then start recirculating immediately instead of waiting for the HLT to cool. It also means I don’t need any electric elements or automation for my burners.

 

[rdavidw]

I used 2 thermometers for the longest time, the first was an analog placed in the centre of the mash and the second a PID in lowest portion of the grain bed and found that with recirculating a direct fire MLT, the temp difference was negligible and closer to no difference nearing the 60 minute mark. No need for inline thermometer in my system. Oh, my MT is a stainless steel keggle and a Jaybird FB.

I see a big delay in my grain bed temp from my wort temp. My flow rate may be too low or my bed may be too compacted, or challenging. I used to stop the pump and re-fluff my bed around a half hour in but did not see a jump in effecentcy. I use a fairly coarse grain crush, a little more than a credit card. My grain bed temp is around a full 10 to 15 min behind my wort temp.

 

[augiedoggy]

I see a big delay in my grain bed temp from my wort temp. My flow rate may be too low or my bed may be too compacted, or challenging. I used to stop the pump and re-fluff my bed around a half hour in but did not see a jump in effecentcy. I use a fairly coarse grain crush, a little more than a credit card. My grain bed temp is around a full 10 to 15 min behind my wort temp.

I use a credit card with no rice hulls... I recirc with a little 24v tan $20 pump at around 1.8gpm on my inline flow meter... there is a delay in my system due to this as well which is why I dough in as close to strike temp as possible but slightly low.

 

[augiedoggy]

Augie do you recirc while underletting? I stir.

no underletting I pump water is and pour grain in while stirring. same at brewpub on the 3bbl setup. I have a couple temp probes in the mash to measure from. one is short and near the kettle wall so I can see the temp drop without recirculation.

I will never consider myself "pro" Most of these nano systems all work like large homebrewing systems until you get into larger setups with mixing rakes and such..

 

[augiedoggy]

mistake post

 

[betaman]

I don't use any thermometers/probes on my MLT as it matches whatever I have my HLT set too. When I first built the system I had a mechanic thermo on the MLT output and did have issues until I adjusted my grist to allow fast enough turnover without compacting the grain bed or causing channeling. If you prefer milling tight to attempt better efficiency you may need to use a probe in the hlt and compensate for the differential. Cheers

The Herms or HLT should be set a couple degrees higher than desired mash temp for transfer loss.

 

[Blazinlow86]

The Herms or HLT should be set a couple degrees higher than desired mash temp for transfer loss.

I don't need to as i adjust my grist to allow fast enough turnover that my MLT out temp matches my HLT temp. If you have to restrict the pumps to avoid a compacted grain bed and channeling it may be required. Cheers

 

[betaman]

I don't need to as i adjust my grist to allow fast enough turnover that my MLT out temp matches my HLT temp. If you have to restrict the pumps to avoid a compacted grain bed and channeling it may be required. Cheers

Different brewers will get different results applying the same principles on the same equipment. It’s understanding how your equipment will react. Just as plastic, copper, stainless steel all have different properties and unless you adjust you variables appropriately they will all yield different results. Cheers and stay thirsty!

 

[Blazinlow86]

Different brewers will get different results applying the same principles on the same equipment. It’s understanding how your equipment will react. Just as plastic, copper, stainless steel all have different properties and unless you adjust you variables appropriately they will all yield different results. Cheers and stay thirsty!

Agreed 100%. Cheers

 

[eric19312]

Yeah, I thought of that and no need for another vessel, I suppose because I only have an analog 3 inch dial therm on my BK, and I have made great beer in my current set up, I just never went to the expense of installing a third PID. Also, I really never understood why use if there is no reason to? Low flame direct heat is more efficient. Will I notice a difference if I used a HERMS?

I have only one PID on the mash tun. Strike water and sparge water temperatures are manually controlled.

I recirculate the strike water while heating using my mash pump--my mash tun temperature probe is located immediately downstream from this pump. This give me a nice bright temperature readout on my PID so I can easily see where I am strike water temperature wise while I go about the rest of my brew prep. High temp silicone hoses and quick disconnects/camlocks make this system feasible. I've tried to figure out a way to design it with hard plumbing and more valves but can't seem to figure out how to get it to do everything I do now without a ridiculously complicated layout.

 

[eric19312]

I used 2 thermometers for the longest time, the first was an analog placed in the centre of the mash and the second a PID in lowest portion of the grain bed and found that with recirculating a direct fire MLT, the temp difference was negligible and closer to no difference nearing the 60 minute mark. No need for inline thermometer in my system. Oh, my MT is a stainless steel keggle and a Jaybird FB.

Its funny I am opposite. I don't worry at all about the actual temperature in the mash tun and rarely even check it. I measure and control my burner using the inline recirculation temperature. The burner is heating the wort below the false bottom and that wort is the hottest part of the mash. By controlling the hottest part of the mash I avoid overheating any of the mash. I aim to dough in a couple degrees low and assume the overall mash will average a little lower than the recirc temp and over time will approach but never quite meet the recirculation temp . This system is it is highly repeatable. Control for 151F on my system is going to be the same temperature profile every time I brew on my system at that temperature. Is my 151F the same as your 151F? Maybe not.

I can appreciate that for @augiedoggy with the his need for transferability of recipes from his home system to his 3bbl system may mean that the actual overall mash temperature may become much more important. 151F on both systems needs to mean pretty much exactly the same thing.

 

[augiedoggy]

I have only one PID on the mash tun. Strike water and sparge water temperatures are manually controlled.

I recirculate the strike water while heating using my mash pump--my mash tun temperature probe is located immediately downstream from this pump. This give me a nice bright temperature readout on my PID so I can easily see where I am strike water temperature wise while I go about the rest of my brew prep. High temp silicone hoses and quick disconnects/camlocks make this system feasible. I've tried to figure out a way to design it with hard plumbing and more valves but can't seem to figure out how to get it to do everything I do now without a ridiculously complicated layout.

I struggled with this too before settling on the layout in my build thread below (towards the end of the thread). its just about all hardplumbed and works well for me however its also a 3 vessel 3 pid setup.. 3 way valves and hardplumbing the pumps inline , knowing you can easily pump liquid backwards through them when they are off, helped.

 

[betaman]

No, that’s not what I am saying, I am saying negligible at worst. Low flame, accurate strike temp and initial dry grain temps are key.

Augiedoggy.... I have given a bit more thought to your temp problem where your mash reads differently top and bottom and I am suspicious if it’s because of a lack of stirring at dough in?

 

[augiedoggy]

Augiedoggy.... I have given a bit more thought to your temp problem where your mash reads differently top and bottom and I am suspicious if it’s because of a lack of stirring at dough in?

I dont imagine you've brewed 3bbls at once but its very difficult to get a complete turnover and get the liquid and grain from the bottom of a 125gallon tun exposed to cooler temps like the liquid does at the top when stirring... (especially the few gallons under the false bottom.) the more you stir the faster the temps at the top drop.
That said when we dough in normally by adding the water and stirring the grain in later ,our temps are not really all that uneven. Its when we tried underletting that the temps are drastically different and stirring that kind of defeats the purpose of underletting in my mid since it would be even harder to stir it all at that point.

 

[betaman]

Great forum about underletting. https://aussiehomebrewer.com/threads/underletting-pros-cons.12144/

 

[augiedoggy]

Great forum about underletting. https://aussiehomebrewer.com/threads/underletting-pros-cons.12144/

just read that thread over and assume those guys are all brewing like 5 gallons with recirculation or still do a lot of mixing anyways. The last post in thread pretty much sums up my thoughts and experiences on it though.

 

[applescrap]

Imho, all of your chosen options are overkill and make little sense other than from a pride of ownership standpoint. Or I guess if you are looking for a lodo setup. If you must spend a bunch then get a co brew system or something like that. Just mo.

 

[augiedoggy]

Imho, all of your chosen options are overkill and make little sense other than from a pride of ownership standpoint. Or I guess if you are looking for a lodo setup. If you must spend a bunch then get a co brew system or something like that. Just mo.

My opinion is it sounds like your using the same argument many beer drinkers use when referring to home brewers vs buying the beer.

With all do respect here, You didnt even yet use your temp controls on your kettle pids as of last time the discussion camp up because it was too much effort. and thats fine since your still able to make beer and enjoy doing it.

Ignorance can be bliss if you dont realize or care what your missing and you dont mind your beers coming out differently every other time you make them.
Yes some of us are mechanically inclined and enjoy improving our brewing processes to make better beer. It does make sense for us to do it for that enjoyment as well as consistency. And yes there are also those that do all this mainly to show off their equipment to friends.. But those are usually the folks who just go out and buy something expensive and shiny (not to say everyone with an expensive blingy setup does this for that reason because its absolutely not true either)

Being able to have actual accurate control of mash temps is about as important as having control over fermenter temps if a person wants to control how the beer will come out as well as efficiency.


This is the equipment section and theres plenty of room to discuss things other than "what brand of kettle or cooler should I buy" Some folks like to keep it simple and some dont. for the same reasons some people have full blown home theaters vs other who just have a simple 32" walmart tv.. different folks different strokes.. No need to attack one another if we dont see things the same way.

 

[mongoose33]

just read that thread over and assume those guys are all brewing like 5 gallons with recirculation or still do a lot of mixing anyways. The last post in thread pretty much sums up my thoughts and experiences on it though.

Here's the pertinent part of that post: "The reason i do not underlet is, because i have a SS keg mash tun with a huge thermal mass, the hot liquor needs to be going in at about 78 Degrees. As it works its way up through the grain, the bottom 1/3 or so of the malt is going to get to mash out temperatures before re-circulation can begin."

It is something that has concerned me a bit, though I'm nowhere near mashout temps....my strike water when underletting is 160-162, and I've considered lowering that even more since my RIMS can raise the temp about a degree/minute with a 5-gallon batch so even if I ended up with, say, 147 as the mash temp, I can raise it to whatever I want.

As to the guy above, I'm surprised he didn't figure out that he should simply add a gallon or so of hot water to the MT to warm it up. I always did that when it was cold in my garage and my cooler MT was cold.

But we're not doing 3-barrel batches, either.

 

[augiedoggy]

Here's the pertinent part of that post: "The reason i do not underlet is, because i have a SS keg mash tun with a huge thermal mass, the hot liquor needs to be going in at about 78 Degrees. As it works its way up through the grain, the bottom 1/3 or so of the malt is going to get to mash out temperatures before re-circulation can begin."

It is something that has concerned me a bit, though I'm nowhere near mashout temps....my strike water when underletting is 160-162, and I've considered lowering that even more since my RIMS can raise the temp about a degree/minute with a 5-gallon batch so even if I ended up with, say, 147 as the mash temp, I can raise it to whatever I want.

As to the guy above, I'm surprised he didn't figure out that he should simply add a gallon or so of hot water to the MT to warm it up. I always did that when it was cold in my garage and my cooler MT was cold.

But we're not doing 3-barrel batches, either.

in my case I tried prewarming the kettle but its the actual grain mass that both lower lowers the temp of the strike water that travels up it and heats up the grain below that causes the higher temps to be maintained towards the bottom. the only way around that huge variance from top to bottom is to preheat all my grain or stir the mash as I fill which defeats the purpose of underletting. if I mash in too low much of the conversion is done at a lower temp by the time I get it all up to temp via 4-5gpm rims flow on a 70-90 gallon mash.