HERMS better than direct-fired recirculating MLT?

[devils4ever]

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?

 

[Bellybuster]

50 amps!!! How big is your system? I run a 30 gallon on 30 amps. 5500 watt element. 23 amps max on 240v

 

[helterscelter]

I've only done the direct fired mash recirculation, so can't really say much about the other options. I'm fairly happy with direct fired recirculation. It works pretty good. You just have to pay attention to how much heat you are adding and how fast your recirculation is.

I always worry about scorching, especially if the recirculation slowed due to bed compaction. So I am personally planning to add a herms coil to my hlt.

A grant would also help in this regard. Bed compaction is a problem whether you direct fire, herms or rims.

 

[normonster]

I was considering some automation in this vein but decided a 1degree drop in an hour is acceptable to me. It is consistent, that's for sure. Just can't justify the cost on that when considering all the other potential upgrades. MHO

 

[devils4ever]

50 amps!!! How big is your system? I run a 30 gallon on 30 amps. 5500 watt element. 23 amps max on 240v

The Blichmann BoilCoil requires a 20/30 A circuit. I need to run two at once. Hence, 50 Amps!

 

[devils4ever]

I have a false bottom that is almost 2" above the bottom of the MLT. So, I have to recirculate the wort manually when adding heat. I don't think scorching is an issue with that much space.

I have some trouble maintaining a constant temp. A controller would be nice.

The only difference with a HERMS is the thermal mass is bigger so temperature changes are slower.

 

[Bellybuster]

The reason I ask about the 50 amps is I had a similar belief that I'd be running two burners at once. For me it never happened and my system had 3 elements. HLT, BOIL and RIMS. The cost difference between 30 and 50 amps is substantial.

 

[devils4ever]

I just thought of an advantage of a direct fired recirculating system. With a true HERMS system, the strike water in the HLT needs to be cooled by 8-12 degrees before it can be used to control the temperature of the MLT. So, I'm leaning towards a DFRS (direct-fired recirculating system). No coil is less $$$ also.

The lack of thermal mass in the DFRS is a drawback. It will be harder to maintain temperature. However, this is a plus when doing a step mash. It will easier to raise the temperature of the smaller thermal mash. Trade-offs.

I've been researching the gas valves for this. Honeywell with thermocouple? I'm thinking about the PIDS controllers out there and I'm thinking that these don't work for gas systems. It will be cycling the gas valve on and off with 1 sec intervals. Bad. I"m thinking a straight thermostat will be better. Temp drops by 1 degree and the it turns the valve on. Temp comes up and valve goes off.

Another question: where does the temperature probe go? In the middle of the mash? At the outlet of the pump?

 

[madscientist451]

My choice of the 3 would be option#2. You already identified some problems with option #1; my opinion of option #3 is that direct firing the mash tun will lead to temperature variations that could be difficult to control. Eventually, you can figure a way around temperature problems but I don't think the hassle is worth it.
What size batches are you going to brew?
Good luck with your project.

 

[brick_haus]

I just thought of an advantage of a direct fired recirculating system. With a true HERMS system, the strike water in the HLT needs to be cooled by 8-12 degrees before it can be used to control the temperature of the MLT.

I just add more water to my HLT after transferring water to the MLT to cool it off. I need more water in there anyway. After a few batches, you get a pretty good feel for how much to add to get the correct temp.

 

[augiedoggy]

The Blichmann BoilCoil requires a 20/30 A circuit. I need to run two at once. Hence, 50 Amps!

curious, how many gallons are you heating at once to need to use two 20+ amp elements? it would have to be over 30 gallons of wort to need that

EDIT** the smaller blichman boilcoils your likely using is only 3750 watts? .... which would mean it only draws 16 amps a piece... It would have been more practical to go with a single 5500w element but the blichmann stuff is sure pretty... even if it is ridiculously priced for a small heating element.... its funny because normally similar elements like you would find in an electric smoker normally sells in the normal range for an element this size... $30-40. (with a controller)

Theres just no practical way for blichmann to justify charging over 3 times that but for a bare element and plug apparently there are a lot of people impressed by them for some unknown reason and buying them... (marketing maybe?)

It would have made more sense to buy the bigger correctly sized boilcoil no? then you would have only needed a 30amp line.. the 30 gallon boilcoil only requires a 30 amp line...

Im sorry if you disagree with my opinion. but I'm having a hard time seeing why people buy these? where is the value and whats the advantage?? Perhaps the $150+ boil coils do something differently or better than the $40 all stainless ULWD elements like kal or bobby sells that are easier to remove and clean? or is it really just a prestige thing? And does it really cost 10+ times as much to make a heating element in the states?

 

[devils4ever]

The 10 gallon 240 BoilCoil shows 3750 Watts and 20/30 Amp recommended breaker size. So, for two would require a 50 Amp circuit. But, maybe I don't need to do two at once?

 

[IslandLizard]

One thing in defense of the (pricey) Blichmann BoilCoils is their super low watt density, because of their length. I doubt you could scorch the mash or wort with them. But you still need a stirrer or recirc system to distribute the heat and prevent overheating the mash/wort.

 

[Gameface]

I just thought of an advantage of a direct fired recirculating system. With a true HERMS system, the strike water in the HLT needs to be cooled by 8-12 degrees before it can be used to control the temperature of the MLT. So, I'm leaning towards a DFRS (direct-fired recirculating system). No coil is less $$$ also.

That's not entirely correct. First, since you're actively controlling temps, you don't need your strike water to be that much above your desired mash temp and many people don't raise it above their desired mash temp at all. They just add the grain to the MT with strike water at their set mash temp (the HLT is also at the correct mash temp) and with a little recirculation the mash comes up to your desired temp.

I do raise my strike water and HLT temp a bit above my mash temps, so if my mash temp is 150f, I might go to 154. After adding grain my grain temp might drop into the mid 140s, I then set my HLT to the desired mash temp (I have to set my HLT 2f higher than the desired mash temp, ymmv) and as the HLT pulls the temp in the MT up the mash tun pulls the HLT temp down and before long they settle out at the desired temps.

That's one of the awesome things about an eHERMS, since you're directly controlling the temps and you're doing it through a large thermal mass it's really easy to get a stable temp pretty quickly while still being able to move that temp if desired. PIDs do the work for you if they're set up correctly.

 

[betaman]

I have a direct fire system with a Herms coil in the HLT. I never used the herms coil in the HLT but manually light and shut off my burner under the MT with a very low flame at 1 degree Celsius variation. I do this as I can’t figure out how to bring the strike water to temp in the HLT, fill the dry MLT with grains first add strike water to the bottom of the MT through the false bottom next which eliminates dough balls and minimizes stir time to 5 mins, then refill the HLT and bring it back to recirculating temp for the mash before temp drops more than the the 1 degree. I recirculate the mash being careful not to channel the grains. Maybe I need another vessel for just HLT? I never have scorching issues.

 

[cswant88]

I have a direct fire system with a Herms coil in the HLT. I never used the herms coil in the HLT but manually light and shut off my burner under the MT with a very low flame at 1 degree Celsius variation. I do this as I can’t figure out how to bring the strike water to temp in the HLT, fill the dry MLT with grains first add strike water to the bottom of the MT through the false bottom next which eliminates dough balls and minimizes stir time to 5 mins, then refill the HLT and bring it back to recirculating temp for the mash before temp drops more than the the 1 degree. I recirculate the mash being careful not to channel the grains. Maybe I need another vessel for just HLT? I never have scorching issues.

Try filling your MLT with your strike water, fill HLT with your sparge and cip water, and then fire the HLT while recirculating the strike water through the HERMS. All of your brewing water should be in those 2 vessels at the start of the brew day. The strike water in the MLT gets heated via the HERMS in the HLT. In a HERMS system, there should be no need to direct fire the MLT. Recirculate water in the HLT as well to keep consistent temps throughout the system (need 2 pumps). Stop recirculating and mash in once your strike water reaches temp, stir to break up any dough balls then start recirculating through the HERMS again. (EDIT: Once you are mashed in, restrict the output on your wort pump to avoid compacting or channeling the grain bed). Hold the water in your HLT a few degrees above your mash temp. The mash should hold a constant temp.

Your current process (heating strike water in HLT and then transferring to MLT) is not how HERMS setup should work.

 

[betaman]

Try filling your MLT with your strike water, fill HLT with your sparge and cip water, and then fire the HLT while recirculating the strike water through the HERMS. All of your brewing water should be in those 2 vessels at the start of the brew day. The strike water in the MLT gets heated via the HERMS in the HLT. In a HERMS system, there should be no need to direct fire the MLT. Recirculate water in the HLT as well to keep consistent temps throughout the system (need 2 pumps). Stop recirculating and mash in once your strike water reaches temp, stir to break up any dough balls then start recirculating through the HERMS again. (EDIT: Once you are mashed in, restrict the output on your wort pump to avoid compacting or channeling the grain bed). Hold the water in your HLT a few degrees above your mash temp. The mash should hold a constant temp.

Your current process (heating strike water in HLT and then transferring to MLT) is not how HERMS setup should work.

And the dough balls are back! Been there! Lol... I know what you are saying but when I add my grains to the dry MT and fill under my false bottom I get better efficiencies as well as better water saturation and no dough balls and no HERMS! I guess I want it all.

 

[eric19312]

And the dough balls are back! Been there! Lol... I know what you are saying but when I add my grains to the dry MT and fill under my false bottom I get better efficiencies as well as better water saturation and no dough balls and no HERMS! I guess I want it all.

I,m a direct fire MLT guy but that probably doesn’t matter. I heat my strike water in my boil kettle so I can underlet my mash. Agree it does wonders for the doughballs, I just never see them anymore.

 

[day_trippr]

^that^ is exactly what I do as well. One good stir to even out the temperature and the mash is off and running.

I run a 3v2p herms and have no experience with direct-fired or tubed-RIMS systems so no idea what is "best". That said, I do believe a hex-based herms is pretty easy to operate with pretty much zero risk of scorching anything...

Cheers!

 

[Blazinlow86]

I dump them in the top, give a stir and start the herms once the hlt is down to temp which is usually 10 mins. I've never had any issues with doughballs. Cheers

 

[betaman]

I,m a direct fire MLT guy but that probably doesn’t matter. I heat my strike water in my boil kettle so I can underlet my mash. Agree it does wonders for the doughballs, I just never see them anymore.

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?

When using electric systems I understand that a HERMS or RIMS are your only options for temp control and therefore more cleaning (calcification), more parts, more money, and more maintenance. With direct fire it just seems easier.

 

[rdavidw]

When I first started with all grain, I only paid attention to the thermometer on the MT and I would end up with very high final gravity readings. Some of my wort was getting too hot and stopping all enzyme action. I now have in-line thermometer on my HERMS return line and only pay attention to that. Way better. I would go with a HERMS setup for that reason. You want to keep all of the wort as close to target temp as you can. If you are only heating the bottom of the MT, the wort at the bottom is going to get way too hot before you see the change in your MT thermometer. HERMS is ideal for keeping all of the wort temp consistent.

My HERMS setup is fairly inexpensive single induction burner with two pumps. I would also recommend electric over gas. I started with a copper coil but over time it started to break down and I replaced it with stainless. I am getting around 88% - 92% efficiency depending on the size of the grain bill.

Cheers!
View media item 70161

 

[betaman]

When I first started with all grain, I only paid attention to the thermometer on the MT and I would end up with very high final gravity readings. Some of my wort was getting too hot and stopping all enzyme action. I now have in-line thermometer on my HERMS return line and only pay attention to that. Way better. I would go with a HERMS setup for that reason. You want to keep all of the wort as close to target temp as you can. If you are only heating the bottom of the MT, the wort at the bottom is going to get way too hot before you see the change in your MT thermometer. HERMS is ideal for keeping all of the wort temp consistent.

My HERMS setup is fairly inexpensive single induction burner with two pumps. I would also recommend electric over gas. I started with a copper coil but over time it started to break down and I replaced it with stainless. I am getting around 88% - 92% efficiency depending on the size of the grain bill.

Cheers!
View media item 70161

Recirculate to eliminate hot spots is a must in any system for temp control.

 

[rdavidw]

Recirculate to eliminate hot spots is a must in any system for temp control.

Agreed! But if you are only heating the bottom of the MT and only have a thermometer in the center of your MT, it will be hard to know how much hotter the wort is under the false bottom then the thermometer reading at the center mass. You could easily go 10 degrees over before the center mass temp catches up. I highly recommend a in-line thermometer directly after flow past the heat source. Just keep that temp on target and your center mass temp will eventually catch up. Under target temp can be fixed with a little more time. Over target temps can't, once its cooked its cooked.

https://www.morebeer.com/products/inline-thermometer-quick-disconnects.html

 

[augiedoggy]

I went with a 36" long rims element in a 42" long tube to preven the denatured enzymes that do occur in many shorter rims setups with higher watt density elements. herms does avoid that with minor time losses and inconveniences that come with it I think unless toy have a rake system constantly stirring the mash or you only apply heat while stirring then direct heating the mash is not ideal but this is based on my knowledge and understanding based on only herms and rims use and not direct firing to heat my mash so... I found that every time I went with a longer rims and element my efficiency went up. I actually went from a 2000w to 1800w watt element thats longer and I get better performance from this longer element than I did from the higher wattage one. I average 91% brewhouse efficiency on 10 gallon brews fairly consistently at home and 85% one a 3bbl stout style electric setup with a similiar 6ft long rims I built for the brewpub and I have zero fears of scorching or denatured enzymes this way.

it seems everyone has a different idea on how these systems are best implimented so to talk about them all as if they were the same thing from build to build is really not very accurate.. They are not all created equally or used the best way to their full potential. The human element makes sure of this.

For example recirculating the wort is commonly done amongst home brewers but in the probrewing world is kind of a no no because it does oxidize the mash and wort unless special percautions are added like purging everything with co2 and running a sealed system.

 

[augiedoggy]

Agreed! But if you are only heating the bottom of the MT and only have a thermometer in the center of your MT, it will be hard to know how much hotter the wort is under the false bottom then the thermometer reading at the center mass. You could easily go 10 degrees over before the center mass temp catches up. I highly recommend a in-line thermometer directly after flow past the heat source. Just keep that temp on target and your center mass temp will eventually catch up. Under target temp can be fixed with a little more time. Over target temps can't, once its cooked its cooked.

https://www.morebeer.com/products/inline-thermometer-quick-disconnects.html

Im going to add that much of the mash is already converted 20 minutes into the mash so if it takes you 15 minutes to get to your desired mash temp you have effectively mashed in at a lower temp than you think you have... I have had to deal with this when I started brewing on a 3bbl electric rims system with 5gpm max flow rate... At that size, mashing in through underletting doesnt work because the large amount of cooler grain causes the water to keep dropping at it climbs up the grainbed being cooled by said grain while the water at the bottom stays hotter, resulting in mash temps at the top of the mash that are 10 degrees lower than the bottom. therefore mashin temps have been the most critical thing for me to control at this point.
It all makes beer in the end but often the temp control people thing they are implementing with some of these procedures and systems is no where near as accurate and repeatable as they think.

 

[betaman]

Agreed! But if you are only heating the bottom of the MT and only have a thermometer in the center of your MT, it will be hard to know how much hotter the wort is under the false bottom then the thermometer reading at the center mass. You could easily go 10 degrees over before the center mass temp catches up. I highly recommend a in-line thermometer directly after flow past the heat source. Just keep that temp on target and your center mass temp will eventually catch up. Under target temp can be fixed with a little more time. Over target temps can't, once its cooked its cooked.

https://www.morebeer.com/products/inline-thermometer-quick-disconnects.html

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.

 

[betaman]

Picture deleted

 

[augiedoggy]

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.

ok but based on that statement if im reading it right your implying at long as they even out by the 60 min mark your good... Thats not at all how mash conversion works.
The area of the grainbed at the bottom that are seeing higher temps will denature and be done/ cooked fairly quickly and everywhere that sees lower temps for as little as 10 minutes will already start converting at that temp resulting in a mix of the mash converting or denaturing at all different temps. im sure its not as drastic in your setup if the flow is good as my example makes it sound but its not really great temp control either

 

[betaman]

ok but based on that statement if im reading it right your implying at long as they even out by the 60 min mark your good... Thats not at all how mash conversion works.
The area of the grainbed at the bottom that are seeing higher temps will denature and be done/ cooked fairly quickly and everywhere that sees lower temps for as little as 10 minutes will already start converting at that temp resulting in a mix of the mash converting or denaturing at all different temps. im sure its not as drastic in your setup if the flow is good as my example makes it sound but its not really great temp control either

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.

 

[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..