Stepping with a HERMS

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Cape Brewing

DOH!!! Stupid brewing...
HBT Supporter
Joined
May 9, 2008
Messages
15,522
Reaction score
1,192
Location
Norton, MA
Oh admit it... you LOVE this topic. Pol's probably sitting at his computer DYING for another thread like this to start. :mug:

Ok... so here's my thought....

For my MT, I use a 20 gal aluminum pot mounted inside a 30 gal alum. pot and then spray foam insulated in between the two to insulate the entire thing. I have a 25ft 1/2 coild suspended in my HLT as my HEX and I constantly circ my MT. I have a PID controlling a 23 tip natural gas "jet burner" to maintain temp in my HLT.

NOW... granted... we're talking a lot of money and a lot of work (what else is new when it comes to brewing???)...

but....

WHAT ABOUT... grabbing another march pump, taking my 20 pot OUT of the 30... wrapping the entire thing in freakin' 1/2 copper soft-drawn and then sliding it back into the 30... making a jackeded MT?

Then, when I want to step, I would maintain circulating through the HEX but then also kick on the pump for the jacket as well. With the amount of heat those burners put out, I would THINK I could step up at a reasonable rate.

'cause really, the problem that is trying to be solved here is the most efficient exchange of heat from the HLT to the MT without over-heating any portion of the wort during step... right?

So the questions are whether or not the burner would keep up with the heat transfer... (NOT worried about that) and then how quickly the step could take place. Hmmm... it would be interesting to give it a shot.

Now... all this being said, I'll probably never do it because, 1) I just finished the freakin' thing so I'm probably not ripping it apart anytime soon and 2) I'm not 100% sure I buy into the need to do steps anyway...

I'm more interested in getting thoughts on plausability.
 
Why not just step up with the HERMS system. Thats exactly what I do. If the water in my HLT is about 190+ it takes my mash tun about 10-15min to go from 128 to 155.
 
There have been long debates on other threads about ways to do it and the majority of posts that I've seen (which I beleive and am "in the camp of") say that you are not supposed ever heat any part of your wort up over your target temp.

So... if you're going from something like 125 up to 154... your HLT should never be higher than 154 (or not much higher than it) since the wort that you are washing through the HTL will come out dramatically above your target temp... so you're going to be beating up on your enzymes pretty fierce.

And if you think about how many times your MT has to completely recirc over that 10-15 minutes... the question is how much are you really raising the temp of the wort as it exits the HEX and what damage is that doing if you're well over the 155 (in your example) mark?

Guys have different ways to try to acheive this... some use temp controllers on the wort itself directly at the point it is coming out of the HEX.... others simply do infusions...

All I'm suggesting is the possibility of increasing the efficiency of heat transfer, while not "overshooting" and step up as quickly as possible through the use of both a HEX and a jacket around the MT.
 
I think this discussion is mostly centered around if, how, why, etc (best practices) for stepping mash temps with heat exchange. We really don't care how the heat is applied but the major question is whether or not the wort at any point in the process can be safely elevated above target temp without denaturing too much and how much hotter IS safe?

I think this is a great discussion to have and again, it should be kept together in the same thread without weighing it down with RIMS vs. direct fire RIMs vs HERMS, etc. It's irrelevant.

Rant aside, even though you turn over the mash through the HEX probably once every 5 minutes, it only stays at the elevated temp for about 20 seconds (the length of time it takes to hit the heat, then equalize back down when it hits the grain again. Let's say it takes 25 minutes to get your mash from 122f to 152f at 1 gpm flow rate where the output of the HEX is 160F. Of course these numbers are completely hypothetical, but the point is that the entire volume of the mash is turned over probably 5 times assuming 5 gallons, 1gpm for 25 minutes. If the time spent at 160f is only 20 seconds per cycle, it's only at 160f for a total of 100 seconds. That's nowhere near enough time to denature b-amylase at 160f. Even if my numbers are off by a good degree, I'd feel fine heating to 160f for a 152f target.
 
Basically, you're trying to improve the heat exchange efficiency without overshooting a specified temperature.

Some other options include:

  1. Use a CFC as a heat exchanger at the expense of two pumps instead of one.
  2. Put the heat exchange tubing inside the MLT instead of the HLT (flip the script).

#1 should result in more efficient heat exchange but may not achieve much towards a rapid temperature increase. #2 would allow for a faster temperature increase since the HLT temperature could be much higher than the MLT and still avoid significantly overheating any portion of the mash.

Has anyone attempted #2?
 
Cape...

HERMS is an EXCELLENT choice for step mashing, that is my new stand on it. I will recommend HERMS to anyone looking to step mash, it is an excellent choice.

HERMS + Step Mash = match made in heaven.

Anyone looking to step mash easily, should build a HERMS, I highly recommend it.

Pol
 
Agreed with Bobby and agreed with lamarguy..

... just trying to see what folks' opinions are on jacketing the MT. That strikes me as something that would significantly increase the effeciency of the heat transfer. It's simply another option... or... a "#3" to your list lamarguy...

Given my set up of one pot mounted inside another... I think I could coil a large portion of the inner pot... even then wrapping THAT with insulation (the silver foil lined bubble wrap stuff) and then slide it back down into the other pot.
 
You should probably note your sarcasm at some point for those who have not been playing along.

There are a lot of variables that make heat exchange for temp changes difficult or maybe impractical but it doesn't hurt talking about them. You don't want to heat over target temp and I'm sort of asking why not.

Of course if the HEX is your HLT, you have an issue of potentially having too cool the water down before sparging if you've got it running at 180f. This isn't all that difficult. If it's an issue of having the horsepower to keep the HLT temp up or getting it up, there's always bigger/more elements. If there's a will there's a way.
 
I am serious too, the number of inquiries I get about HERMS is high... from here on out I am recommending it. IF it doesnt work for them, I will send them to yous guys. I wil throw "pixie dust photon heat exchanger" into my parts list.

Pol
 
Agreed with Bobby and agreed with lamarguy..

... just trying to see what folks' opinions are on jacketing the MT. That strikes me as something that would significantly increase the effeciency of the heat transfer. It's simply another option... or... a "#3" to your list lamarguy...

Given my set up of one pot mounted inside another... I think I could coil a large portion of the inner pot... even then wrapping THAT with insulation (the silver foil lined bubble wrap stuff) and then slide it back down into the other pot.

It sounds like a big pain in the ass to me having to run two different circulation loops but this is coming from a guy who is really considering going back to single infusion mashing in a cooler.
 
I get the arguments...I honestly do...


Let's just use hypothetical numbers here for a second (bear with me).

MT... HLT... HEX in the HLT... raise the temp in the HLT to 190 degrees and you can get 10 gallons of mash to step up 30 degrees from 125 to 155 in 30 minutes with the mash exiting the HEX at... 185 degrees (again... I'm making up numbers to sum up all of the other posts).

Here are the questions... Is the few seconds at 185 a problem??? Is the 30 minutes it took to get there a problem?

For a minute assume "yes" to both of those questions...

If the answer truly is "yes"... then at what point of... I dunno... "effeciency of heat transfer" does the problems with those two situations begin to get mitigated??

IS there a point where heat transfer is so efficient that you can do it in 10 minutes by only heating your HLT to one sixty???? two... or something... so that the temp coming out of the HEX is still at or below your target and you can do it very quickly.

Guys have seemed to have answers but I still don't get it... (which sounds like it's coming out in Pol's frustrations).

I'm trying to figure out if jacketing while running a HEX might provide enough pixie dust.

- mash-in at 125...
- circ...
- stop circ last ten minutes and jack up HLT to... 160
- circ and kick on jacket pump... while PID controller burner conitnues to maintain 160 in the HLT

... Would you get to the next step fast enough??
 
It sounds like a big pain in the ass to me having to run two different circulation loops but this is coming from a guy who is really considering going back to single infusion mashing in a cooler.

Yup... totally agree... just looking for hypotheticals here.

just looking for... "nope, that's stupid" or "only way we'll know if you get there fast enough and if it is effcient enough is if you build it and test it"

ehhh... WTF... I got that kinda time.
 
Cape,

I am not frustrated, just changing my position, much like a politician.

I was told by two HBTers in the past weeks, that admitted they had not brewed with grain before, that they COULD in fact use a HERMS to step mash easily.

I was wrong, they showed me the light. I was blinded by my experiences and not open to thier views. I see the light now. I have simply changed my views and I m pretty sure one is in the process of building his HERMS for step mashing.

Happy mashing yall! :eek:
 
... I've seen bitterness before... it looked a lot like that.

C'MON!!!!!!!!!! Jacketed MT??

"Meh... maybe"
or
"it's pixie dust"

Throw a HBT'r a freakin' bone here.
 
Build it, test it... ask some of the noobs, they got thier **** together.
 
It would be appreciated by those of us who don't claim to know it all for you not shut down in the conversation because of a few people that do claim it. I appreciate that you have a working HERMS system running and do have a lot more practical data to work with. However, you have ONE implementation of an automated HEX based system. It by no means represents all of them or even potential ones that haven't been thought of.

I wanted to make sure I understand your "real" position on this. Assuming sarcasm in your previous two posts here.. you cannot effectively step mash with a HERMS because _____________.

I previously understood that there were two problems.

1. The heat source in the HLT takes too long to get the water up to a temp that would effectively impart the heat to the coil. If that's the case, can this issue be addressed by higher BTU output?

2. Even if the heat source was up to the task, you wouldn't want the temp of the wort coming out of the HEX to be any higher than the mash target temp. If that's the case, why exactly? How much hotter WOULD you be willing to go? If it were proven that b-amylase is not effectively denatured at a given temp, is there still a reason not to overshoot?

I might assume that #2 is undesirable because you have to babysit the overall mash temp. IOW, if your pump is run full time and the set temp is 160F, you'll end up at 160F mash if you don't watch it. This may be solved by putting a simple shut off controller on the pump with the probe on the MLT output.

I think this is a good discussion because I haven't implemented a semi-automatic system yet so I have nothing invested.
 
It would be appreciated by those of us who don't claim to know it all for you not shut down in the conversation because of a few people that do claim it. I appreciate that you have a working HERMS system running and do have a lot more practical data to work with. However, you have ONE implementation of an automated HEX based system. It by no means represents all of them or even potential ones that haven't been thought of.
I wanted to make sure I understand your "real" position on this. Assuming sarcasm in your previous two posts here.. you cannot effectively step mash with a HERMS because _____________.

I previously understood that there were two problems.

1. The heat source in the HLT takes too long to get the water up to a temp that would effectively impart the heat to the coil. If that's the case, can this issue be addressed by higher BTU output?

2. Even if the heat source was up to the task, you wouldn't want the temp of the wort coming out of the HEX to be any higher than the mash target temp. If that's the case, why exactly? How much hotter WOULD you be willing to go? If it were proven that b-amylase is not effectively denatured at a given temp, is there still a reason not to overshoot?

I might assume that #2 is undesirable because you have to babysit the overall mash temp. IOW, if your pump is run full time and the set temp is 160F, you'll end up at 160F mash if you don't watch it. This may be solved by putting a simple shut off controller on the pump with the probe on the MLT output.

I think this is a good discussion because I haven't implemented a semi-automatic system yet so I have nothing invested.

I fully understand that my system does not represent all... luckily for me, my experience with HERMS is not limited to my system.

First off, I have had enough of the "know it all" attitudes on this board from people that have not put what they are talking about into practice, that yeah... I prefer to watch them learn on thier own dime and save my precious breath at this point. If someone WANTS to be right, well, they will be.

And when it comes to pixie dust, the ONLY way to get an answer is to put your money where your mouth is and build the thing. I didnt know how to create the thermodynamic equations to manage my HLT until I built my system and ran it... some things you cannot conjur.

Point #1. This heat source will have an effect on the time it takes. This could be remedied with a larger heat source, OR by stopping the recic. long enough to get the HLT temp. up to snuff. This plays a role, but this alone will not solve the issue.

Point #2. I personally do not want to overshoot the desired mash temp. Why? Denaturing enzymes? Meh, maybe... but what about the fact that you are returning HOT wort to the top of the grain bed and sucking cool wort out the bottom. Without a mash stirrer (which negates one benefit of running a HERMS anyway) you will have serious temp stratification in the mash. If you return 170F wort to the top of the mash, by the time the bottom of the mash gets to sacc. rest, what is the temp at the top? 170F? Yep, you CAN step with a HERMS, but I dunno about the mash profile.

So, since you have this issue with overshooting, here is the issue with NOT overhsooting. The closer your MLT temp gets to your HLT temp, the SLOWER the temp rise in the MLT becomes. Thusly, YOU HAVE to overshoot the return wort to speed up the step... but, when you do that you MAY denature enzymes, or at the very least have temp stratification in your mash. To me, this makes a HERMS pointless. You have now effectively LOST temp control in your mash, because there are hot and cold spots. Some areas well above sacc. temp and some below.

You cannot measure temp for any control at the output of the MLT... for the afore mentioned reason. If you are returning 160F or 170F wort to the top of the MLT to get a quick step, the bottom of the MLT will read 155F when the top of the mash is a steaming 165F. Not desireable, IMHO.

YES, you can step with a HERMS, but at what cost to control over the process? IMHO, it is easier and more reliable to make a quick infusion from the HLT, which is what my spreadsheets and sight gauges allow for.
 
It would be appreciated by those of us who don't claim to know it all for you not shut down in the conversation because of a few people that do claim it. I appreciate that you have a working HERMS system running and do have a lot more practical data to work with. However, you have ONE implementation of an automated HEX based system. It by no means represents all of them or even potential ones that haven't been thought of.

I wanted to make sure I understand your "real" position on this. Assuming sarcasm in your previous two posts here.. you cannot effectively step mash with a HERMS because _____________.

My herms system heats wort to the set temp (not above) of my mash set temp. Using this technique I can step protein to sach, and sach to mashout in about 20 minutes each (15 gallon MT).

I previously understood that there were two problems.

1. The heat source in the HLT takes too long to get the water up to a temp that would effectively impart the heat to the coil. If that's the case, can this issue be addressed by higher BTU output?

This isn't necessarily true. My herms exchanger is separate from my HLT. I use 1 gallon cooler w/copper coils and a 120VAC/2KW immersion heater. I can step the recirculating temp incredibly fast... it's the mash that takes time to catch up

2. Even if the heat source was up to the task, you wouldn't want the temp of the wort coming out of the HEX to be any higher than the mash target temp. If that's the case, why exactly? How much hotter WOULD you be willing to go? If it were proven that b-amylase is not effectively denatured at a given temp, is there still a reason not to overshoot?

Based on my experience and in talking to others I do not believe that enzymes are destroyed by heating the recirculating wort above the denaturing temp. I initially did until one day my temp probe stopped working and I ran the wort through the exchange at 170F to heat the MT from 130F to 153F . It fermented like any other of my 153F mashes (down to 1.015) with standard efficiency and no problems.


I might assume that #2 is undesirable because you have to babysit the overall mash temp. IOW, if your pump is run full time and the set temp is 160F, you'll end up at 160F mash if you don't watch it. This may be solved by putting a simple shut off controller on the pump with the probe on the MLT output.

I think this is a good discussion because I haven't implemented a semi-automatic system yet so I have nothing invested.

Just the experiences of one homebrewer.
 
FWIW, with highly modified malts, I think a 20 minute step is too slow for my liking. Heck, half of your conversion takes place during the "ramp" up.

Also, even if enzymes arent destroyed if the mash water is heated in excess of the desired MLT temp... you are creating a temp stratification issue that will result in a different mash profile.

So it is either 20 minutes, which is not to my personal liking. OR, overshoot and ruin my MLT temp control and create stratification in the mash where I am mashing the grain anywhere from 152F to 160F in the same mash.

I mean, if you recirculate wort at a higher temp than the target temp in the MLT, how will you know when to stop doing so? When the top of the mash is at the target temp? The middle? The bottom? Because you see, they will all be different temps. And if I do this, my HERMS control is lost.

I am sticking with my HLT infusions to the MLT, it is easy, instant and reliable and takes the flip of one switch to do so.
 
The smaller the heating container ( 3 gallons or less) with the larger wattage elements have been the more succesful herms designs seen lately. With 10+ gallons to heat for temperature control of a herms system the response lag is too large for most PID controllers to handle. With past experience with step mashing it was easy to get 80% of the way to the next step but the last 20% takes time if you hold the wort temp to target + 2 degrees. Temperature stratification was not a big issue as the ramp up to the 80% of step temperature was in about 6-8 minutes, the next 5 minutes were taken up with the last 20% of the step. With the fully modified malts we have today it is not necessary to do step mashes for most beer styles, only style that benefits is large wheat beers (1.060+) 60%+ wheat, a protien rest is nearly always essential to avoid stuck mash.
 
I've come to the conclusion the only way to truly step up quickly with a HERMS or a RIMS without heating above the target is to use a faster flow rate. Problem with that is over compacting the mash bed and getting a stuck mash.

Perhaps if the reentry of the liquid could enter the mash bed at variable locations this would equate stirring the mash. I would wonder about the effect on channeling in such a system.

I'm doing step mashes with a DF-RIMS but they either take a significant amount of time or I can raise it fairly quick, but I have to raise the liquid (as measured at the return) higher than the target. How much this effect the characteristics of the beer in comparison to a single infusion, I don't know. I can get it up fairly quickly but the return is measuring a significant temp above target.

Really what you would want in an ideal world is a quick exchange of temperature top the mash without going over target in any one area. Even with steam this is an issue.
 
Fast flow rate is the key IMO. Faster flow turns over the entire mash volume more frequently and this provides a uniform grain bed temperature. Faster flow also facilitates temp ramp ups without overheating the wort.
 
IMHO, a reasonable flow (not too fast), small volume heat exchanger and a fairly large electric element (controlled according to the temperature of wort exiting it) is the recipe for success.

This will give a system that circulates all the wort through the heat exchanger within say 2-3 minutes, maintains the heat in the heat exchanger and prevents the wort from being overheated.

/Phil.
 
Two things....

Built it, build it.

Enough talking already, build a HERMS.
 
Wow.. I knew this topic would raise hairs because it has on other thread but man... I asked a pretty straight forward question...

Do you think a jacketed MT might get MY set-up a bit closer to actually being able to do it?

I'm not claiming to know it all by any stretch... that's why I asked the question.

I think it's a really interestesting topic and one folks have a lot of thoughts about and if my particular set-up, with some modification is another option to getting it done, cool, maybe someone else can learn from it and then improve on it even more.... without trying to sound all melodramtic about it... I thought that was the purpose of this board.

And I did build a HERMS... works great. I love it. I don't step with it because I haven't seen the need to but with the conversations on this board it got me thinking on whether or not I COULD if I wanted to... hence the jacketed idea.. hence the question...

Hell... maybe I will build it and test it out... I think that's a big part of homebrewing in general... trying new things, seeing if it works... if it does, great... if it doesn't, ehh... you tried.



In terms of flow rate... as mentioned... For some reason I don't really have a problem with compacting my mash and I run my March 809 through 1/2 copper wide open while I recirculate. I have a copper manifold mounted underneath a false bottom and I use anywhere between 1.3 and 1.5 gallons of water per lb of grain. I've only had one stuck mash and I'm convinced that was more of a crush problem than anything.

So I THINK I can keep my flow rate up pretty high... I am not worried about BTU's with my burner....

So again... it all comes back to whether or not the efficiency of the heat transfer would provide for a quick enough step.

... and to Pol's point... probably no way of knowing unless it gets built.
 
IMHO, a reasonable flow (not too fast), small volume heat exchanger and a fairly large electric element (controlled according to the temperature of wort exiting it) is the recipe for success.

This will give a system that circulates all the wort through the heat exchanger within say 2-3 minutes, maintains the heat in the heat exchanger and prevents the wort from being overheated.

/Phil.

I saw you mentioning this on the other thread... and that would be a much easier modification to my system then this jacketed idea. All I would have to do is change my PID to control temp exiting the HEX instead of the HLT itself.

... it just sounds counterintuitive..... that you would be be able to, at a slow flow rate, just heat to the desired temp as it exits the HEX and be able to step quickly. On what size batches?? (sorry.. you probably mentioned that in another thread and I missed)
 
I am sticking with my HLT infusions to the MLT, it is easy, instant and reliable and takes the flip of one switch to do so.

yeah... ultimately my educated guess is I'll do the exact same thing... but I'm still curious.

You said something earlier I wanted to ask you about though.... why does stirring the mash during recirculation defeat the purpose of a HERMS? Reflecting my probable ignorance... I thought the whole point of a HERMS was to simply constantly "mix" the mash by circulating the wort through it to get a more even and complete conversion. Why would actually mixing the mash during that process hurt?

Or are you simply saying you shouldn't have to mix it in the first place given the HERMS process?

I don't have a decent sparge arm yet (the ONE freakin thing I just haven't bothered to build) so two or three times during my mashing I'll give it a bit of a stir just to make sure I'm not channeling through it anywhere.
 
I am not meaning to be an arse guys. But the question of whether or not you can step with a HERMS, has been around as long as HERMS. There is no SOLID answer yet, which leads me to believe that it isnt as easy as some may think.

I think there are a lot of great ideas here, now we just need some $$ and materials to put some of the ideas into practice in a real mash to get real data points to determine what works and what doesnt.

It is like BIAB, or no chill brewing... yah yah, it wont work because Palmer and Jamil say so. Whatever... I have learned that taking theory over actual results is pointless in many cases. Or that you HAVE to add water to grain when you mash in... oh, cmon Palmer. A world of homebrewers can and will find better ways, but it has to be put into practice.

HERMS can be used for stepping, someone just has to find out how, why and the variables involved. Volumes, wattage, BTUs, flow rate and what effects there are on the temp. integrity of the mash during the process.

It can be done, it will be done... but someone has to do it.

IMHO a jacketed MLT will work if you get the jacket hot enough. Though I think that you will need a mash mixer to get the mash away from the hot walls of the MLT, I am not sure that a simple recirc of the wort will do it. Again, I dont know because I have never done it. But this is not a HERMS, this is a jacketed MLT.
 
yeah... ultimately my educated guess is I'll do the exact same thing... but I'm still curious.

You said something earlier I wanted to ask you about though.... why does stirring the mash during recirculation defeat the purpose of a HERMS? Reflecting my probable ignorance... I thought the whole point of a HERMS was to simply constantly "mix" the mash by circulating the wort through it to get a more even and complete conversion. Why would actually mixing the mash during that process hurt?

Or are you simply saying you shouldn't have to mix it in the first place given the HERMS process?

I don't have a decent sparge arm yet (the ONE freakin thing I just haven't bothered to build) so two or three times during my mashing I'll give it a bit of a stir just to make sure I'm not channeling through it anywhere.

I am not certain, but I think I said it defeats some of the benefit. One great benefit to HERMS or RIMS is setting up a stellar grain bed and having crystal clear wort to start with. Obviously if you are stirring the grain bed, this will not occur.
 
Gotcha... makes sense.

I think I'm getting around that problem slightly with the manifold mounted underneath a false bottom. My false bottom doesn't fit my MT EXACTLY so I used some heat/food safe tubing to act as a gasket around the false bottom... and that doesn't fit exactly either so while 99% of my grain bed is held up by the false bottom, I do get grains around my manifold filtering as well.

It's a decent point though and I'll probably stop stirring as I get clsoe to finishing up the mash.. just so it'll clear completely.
 
Do you think a jacketed MT might get MY set-up a bit closer to actually being able to do it?

Will it get you closer? Absolutely. Will it be enough? There is know why to know without going through a very detailed design and testing.

I work with several people who have spent the better part of 30 years designing jackets and jacket loops. It is not generally something you can just eyeball.

I think you are on the right path but you need to define a few more of you parameters or start building and actually test it before you'll get much closer to anything resembling an answer.

Good luck! :mug:
 
There are a lot of great ideas... Id just like to see people build something. There are probably several rigs that could be built from this one thread alone... and maybe there would be a "better" HERMS solution.

Face it, stepping with a HERMS, though possible, aint easy, or there would not be this much discussion here or elsewhere about it.
 
IMHO a jacketed MLT will work if you get the jacket hot enough. Though I think that you will need a mash mixer to get the mash away from the hot walls of the MLT, I am not sure that a simple recirc of the wort will do it. Again, I dont know because I have never done it. But this is not a HERMS, this is a jacketed MLT.

I would do steam injection if I cared to actually do it...use an old pressure cooker, much more straightforward than building a jacketed MLT, albeit with it's own risks...kaboom...
 
My $0.02

With past experience with step mashing it was easy to get 80% of the way to the next step but the last 20% takes time if you hold the wort temp to target + 2 degrees. Temperature stratification was not a big issue as the ramp up to the 80% of step temperature was in about 6-8 minutes, the next 5 minutes were taken up with the last 20% of the step.

I completely agree with this. Who cares if the mash is temporarily stratified during the step. We're only talking about a few minutes. As you get close to the target, there's not much stratification. This really bothers some people. Not me.

I agree with Bobby and some of the others that overshooting the target temp on the HEX is critical for quick steps. I don't think you'd want to overshoot by much, though, for the denaturing issue. What I don't know is how much higher is safe/advisable. Also, the closer the mash gets to the target, the less you should overshoot. This could be done in an automated manner, but it would take some custom programming for each system and probably some trial and error. Amazingly, it's pretty simple to do in an unautomated manner (as long as you can measure the out-temp from the HEX), and is one reason I'm considering NOT automating my system.

Stirring the mash. Why not during the step? I only see benefits here - such as reducing the stratification problem (if that's really a problem). The mash will reset and clear again after you stop stirring.

Jacketed MLT idea. It might work, but actually, I think using a coil inside the mash, like the iHERMS idea, would work better. A jacketed MLT will only apply heat to the outside of the mash. You would need a really good mash mixer, not just a go-round-and-round, design to help with this. A coil inside the mash is going to distribute the heat faster and more evenly. I still think you need a good mash mixer with this design, too, but it wouldn't be so critical to exchange the mash in a center-to-outside manner like with the jacket.
 
See, then step mashing in a HERMS works for you. You are willing to accept the limitations that it inherently has. I mean, they may have no effect at all on a brew session.

But for me, being paranoid, a simple infusion that will bypass all of the possible limitations of a HERMS recirculating step, makes more sense.

Actual mileage may vary.

Results not typical.

Some limitations apply.

For a limited time only.


Etc.
 
I saw you mentioning this on the other thread... and that would be a much easier modification to my system then this jacketed idea. All I would have to do is change my PID to control temp exiting the HEX instead of the HLT itself.

... it just sounds counterintuitive..... that you would be be able to, at a slow flow rate, just heat to the desired temp as it exits the HEX and be able to step quickly. On what size batches?? (sorry.. you probably mentioned that in another thread and I missed)

I didn't say a "Slow flow rate", I said, "Reasonable flow". The reason I said this is that too fast a flow will result in a stuck/set mash

I make 10 imperial gallon batches and I recirculate continously throughout the mash.

If the mash bed is at 50C and I dial in 66C to the PID, the element in the heat exchanger will come on and heat the water bath up to what ever temperature is required to result in the wort exiting the HEX at 66C. Then it will maintain that temperature.

The element will bring the temperature of the recirculated wort to 66C in about 2 minutes while recirculating at my typical flow rate. At this point 66C wort is being deposited just beneath the surface of the mash.

Now assuming the flow is sufficient to recirculate the entire wort in 2-3 minutes that gives roughly 2.5 changes of wort at the 66C within a 10 minute period.

This is where you have to decide whether or not this is fast enough of a step for you. I suppose it's more of a ramp but don't tell The Pol ;)

In my experience this is enough to raise the temperature of the mash to the desired 66C.

/Phil.
 
Jacketed MLT idea. It might work, but actually, I think using a coil inside the mash, like the iHERMS idea, would work better. A jacketed MLT will only apply heat to the outside of the mash. You would need a really good mash mixer, not just a go-round-and-round, design to help with this. A coil inside the mash is going to distribute the heat faster and more evenly. I still think you need a good mash mixer with this design, too.

Ya, I gave the same recommendation. Assuming the inner coil is large enough to evenly distribute the heat, you should be able to induce a large temperature differential between the HLT and MLT to achieve time efficient step mashing.

And, like you said, stirring during step-ups will be necessary to evenly heat the inner mash. That is, unless you go with a "rib cage" style copper heat exchanger and/or add a second pump to just recirculate the mash.
 
Just to throw another wild idea into the mix...

What about a heated mash mixer? You could mix and heat the mash while recirculating. Once the steps are completed, you recirculate as normal to clear the wort and set the grain bed.

I do step mashes so rarely that I'm really following this post (and the others) out of sheer curiosity.
 

Latest posts

Back
Top