eHerms - low efficiency

[RPh_Guy]

I feel like a broken record bringing it up over and over but the biggest obstacle I see causing lower efficiency on a recirculating system is channeling... Which is remedied by recirculating at a lower flow rate. too often I hear of people trying to recirculate as fast as possible or way too fast thinking its somehow going to improve the temp regulation. with a herms you can set the flow as little as 1-2gpm and still hold temps as well as stepmash fine and your going to get higher efficiency due to less compacting of the grainbed.

Background: I'm setting up an 5 gal eHERMS and I have a digital flow meter. My pump circulates water through all the fittings at a maximum rate of 4gpm. I condition my grain, and I'm considering using rice hulls.

Questions:
Do you suggest starting the flow pretty low after dough-in and gradually ramping the flow, or does that not matter too much? Would this help set the grain bed?
What do you think about increasing the flow rate while stepping? How much is too much? I know it's probably system-dependent but any advice is appreciated.

Thanks

 

[Blazinlow86]

I feel like a broken record bringing it up over and over but the biggest obstacle I see causing lower efficiency on a recirculating system is channeling... Which is remedied by recirculating at a lower flow rate. too often I hear of people trying to recirculate as fast as possible or way too fast thinking its somehow going to improve the temp regulation. with a herms you can set the flow as little as 1-2gpm and still hold temps as well as stepmash fine and your going to get higher efficiency due to less compacting of the grainbed.

Another broken record here. I agree with augie that channeling is a problem on recirculating systems and can cause poor efficiency and add abit to it. I brew on a Kal clone and like most herms users I heat my MLT using the Herms coil and adjust my process depending on the grist/ recirculation rate I choose and neither method gives a noticible increase in efficiency because im avoiding channeling by adjusting my grist. If I mill loosely I won't have to circulate slowly to avoid channeling and therefore I can mash in at my desired mash temp with only a 1-2 minute drop in temp once adding the grain making the process abit easier. Alternatively if I mill tightly and therefore have to recirculate slowly I also have to overshoot the mlt/ hlt temp to compensate for the Mash temp dropping once the grains added as a typical non recirculating brewer would. I then additionally need to wait until the hlt temp drops before I can start circulating again which on my setup takes about 20 mins. With a rims setup you won't need to worry about this. Cheers

 

[augiedoggy]

Background: I'm setting up an 5 gal eHERMS and I have a digital flow meter. My pump circulates water through all the fittings at a maximum rate of 4gpm. I condition my grain, and I'm considering using rice hulls.

Questions:
Do you suggest starting the flow pretty low after dough-in and gradually ramping the flow, or does that not matter too much? Would this help set the grain bed?
What do you think about increasing the flow rate while stepping? How much is too much? I know it's probably system-dependent but any advice is appreciated.

Thanks

well I brew on two systems... the false bottom in my 3bble mash tun is 29" in diameter and I recirculate at no more than 5gpm and usually about 4gpm... at home I start the mash at about 1gpm and over the course of about 2-3minutes I slowly bring it up to a max of 1.8gpm (15" diameter false bottom) this nets my 86% efficiency on the 3bbl and 91% efficiency on the 10 gallon... now I use rice hulls on the 3bbl but not the 10 gallon and never have conditioned or adusted my gap... I have my home mill at 1.030 and the one at the brewpub is like 1.040 speeding up the flow for step mashing is not worth it. Even at 2gpm your still recirculating the whole mash through the herms or rims in like 5 mins..

 

[Blazinlow86]

Background: I'm setting up an 5 gal eHERMS and I have a digital flow meter. My pump circulates water through all the fittings at a maximum rate of 4gpm. I condition my grain, and I'm considering using rice hulls.

Questions:
Do you suggest starting the flow pretty low after dough-in and gradually ramping the flow, or does that not matter too much? Would this help set the grain bed?
What do you think about increasing the flow rate while stepping? How much is too much? I know it's probably system-dependent but any advice is appreciated.

Thanks

It's your dough in process that matters for the flow rate on a herms setup as the hlt causes some specific limitations that aren't there on a rims set-up like I believe Augie uses. Are you planning to heat the strike water to your desired mash temp then dough in and use the herms to maintain that temp or are you planning to overheat your strike water so after dough in your mash settles at the desired temp without using the herms? If you choose method one you will need to be able to circulate faster immediately to avoid your mash temp being lower than desired for considerable amounts of time and that will require a course mill setting to avoid channeling. Method 2 avoids needing to circulate quickly from the beginning but requires waiting for the hlt to cool down before you can start your circulating which also takes considerable time depending on your process. Keep in mind this only applies when using a Herms and not if your using a rims setup. With a rims setup higher flow rate aren't required. Cheers

 

[augiedoggy]

It's your dough in process that matters for the flow rate on a herms setup as the hlt causes some specific limitations that aren't there on a rims set-up like I believe Augie uses. Are you planning to heat the strike water to your desired mash temp then dough in and use the herms to maintain that temp or are you planning to overheat your strike water so after dough in your mash settles at the desired temp without using the herms? If you choose method one you will need to be able to circulate faster immediately to avoid your mash temp being lower than desired for considerable amounts of time and that will require a course mill setting to avoid channeling. Method 2 avoids needing to circulate quickly from the beginning but requires waiting for the hlt to cool down before you can start your circulating which also takes considerable time depending on your process. Keep in mind this only applies when using a Herms and not if your using a rims setup. With a rims setup higher flow rate aren't required. Cheers

I believe most with a 3 vessel herms choose to heat their strike water in the adjacent BK to avoid these limitations but I could be wrong

 

[Blazinlow86]

I believe most with a 3 vessel herms choose to heat their strike water in the adjacent BK to avoid these limitations but I could be wrong

Great point and a great option if you have a 50amp back to back setup or are on gas but from the time I spent on kals site when I built my system majority only have a 30 amp setup that can only fire the hlt or bk one at a time and therefore can't really do that. Cheers

 

[RPh_Guy]

Are you planning to heat the strike water to your desired mash temp then dough in and use the herms to maintain that temp or are you planning to overheat your strike water so after dough in your mash settles at the desired temp without using the herms?

Indeed I will be "over-heating" the strike water in the kettle (using propane) to achieve mash temp immediately upon dough-in. The water in my HLT will be heated separately to the desired mash temp (using electric).
I don't sparge, so the HLT will only need a small amount of water.

I'm using a stainless CFC as the heat exchanger, with a RIMS tube and PID heating the water going into it.

 

[doug293cz]

Background: I'm setting up an 5 gal eHERMS and I have a digital flow meter. My pump circulates water through all the fittings at a maximum rate of 4gpm. I condition my grain, and I'm considering using rice hulls.

Questions:
Do you suggest starting the flow pretty low after dough-in and gradually ramping the flow, or does that not matter too much? Would this help set the grain bed?
What do you think about increasing the flow rate while stepping? How much is too much? I know it's probably system-dependent but any advice is appreciated.

Thanks

If you increase the flow rate, you run the risk of establishing channels in the grain bed. Once you establish channels, slowing the flow rate back down will not eliminate the channels. You would have to stir the mash, and then reset the grain bed to get rid of the channels.

Brew on

 

[Blazinlow86]

Indeed I will be "over-heating" the strike water in the kettle (using propane) to achieve mash temp immediately upon dough-in. The water in my HLT will be heated separately to the desired mash temp (using electric).
I don't sparge, so the HLT will only need a small amount of water.

I'm using a stainless CFC as the heat exchanger, with a RIMS tube and PID heating the water going into it.

Disregard what I suggested in that case. I assumed you were using a electric setup. Cheers

 

[RPh_Guy]

If you increase the flow rate, you run the risk of establishing channels in the grain bed. Once you establish channels, slowing the flow rate back down will not eliminate the channels. You would have to stir the mash, and then reset the grain bed to get rid of the channels.

Brew on

That makes sense.
What would you say is a reasonable maximum flow rate to avoid channeling for a normal gravity 5 gal batch, full volume mash (~8 gal strike water), 12" false bottom?

I don't know how I would know if there's channeling going on. I should track my efficiency, maximum flow rate, and other variables to try to find the efficiency sweet spot for my system?

Disregard what I suggested in that case. I assumed you were using a electric setup. Cheers

It's all good, thanks anyway. Maybe I shouldn't call it eHERMS if I also use propane (although not during the mash). ?

 

[doug293cz]

That makes sense.
What would you say is a reasonable maximum flow rate to avoid channeling for a normal gravity 5 gal batch, full volume mash (~8 gal strike water), 12" false bottom?

I don't know how I would know if there's channeling going on. I should track my efficiency, maximum flow rate, and other variables to try to find the efficiency sweet spot for my system?

It's all good, thanks anyway. Maybe I shouldn't call it eHERMS if I also use propane (although not during the mash). ?

Max flow rate is going to depend on the grain bill make-up, fineness of crush, grain bed depth, MLT cross section area, etc. You really have to determine what works for your system. I wish I knew a simple way to determine when channeling was initiated. Tracking both conversion and lauter efficiency is the best way to go, but will take multiple batches to narrow down.

Brew on

 

[Blazinlow86]

That makes sense.
What would you say is a reasonable maximum flow rate to avoid channeling for a normal gravity 5 gal batch, full volume mash (~8 gal strike water), 12" false bottom?

I don't know how I would know if there's channeling going on. I should track my efficiency, maximum flow rate, and other variables to try to find the efficiency sweet spot for my system?

It's all good, thanks anyway. Maybe I shouldn't call it eHERMS if I also use propane (although not during the mash). ?

If you have a sight glass on your mlt the level will drop when you start circulating if your flow rate is to fast for your grist etc. Obviously this isn't a very scientific way but it will get you in the ballpark and avoid channeling/ compacting the grain bed. As Augie mentioned with your process you won't need much flow to maintain your temp . Should be smooth sailing. Cheers

 

[RPh_Guy]

Tracking both conversion and lauter efficiency is the best way to go, but will take multiple batches to narrow down.

Conversion efficiency would be the best indicator, right?

I'm not sure channeling would affect lautering efficiency for no-sparge. Or not very much?

Should be smooth sailing.

Thanks, I hope so.

I don't have a sight gauge, so that's not an option for me.

 

[doug293cz]

Conversion efficiency would be the best indicator, right?

I'm not sure channeling would affect lautering efficiency for no-sparge. Or not very much?

Thanks, I hope so.

I don't have a sight gauge, so that's not an option for me.

Conversion efficiency is a good metric. And no, channeling will not affect lauter efficiency for no-sparge or batch sparge, as long as the mash is stirred well prior to each run-off.

Brew on

 

[RPh_Guy]

Thanks everyone, sounds like a plan.

 

[Bobby_M]

Indeed I will be "over-heating" the strike water in the kettle (using propane) to achieve mash temp immediately upon dough-in. The water in my HLT will be heated separately to the desired mash temp (using electric).
I don't sparge, so the HLT will only need a small amount of water.

I'm using a stainless CFC as the heat exchanger, with a RIMS tube and PID heating the water going into it.

There's another method many people overlook. Fill your HLT to the top of the HERMS coil and fill the MLT with the exact strike volume you need. Fire the system up with an HLT target only 3F above mash target. The strike will heat up through the HERMS and the MLT will be perfectly preheated. This puts the HLT at the right temp for mash recirc. You can get up and running 100% on electric. Even though it will take longer to heat, it's hands off so go eat breakfast.

 

[Blazinlow86]

There's another method many people overlook. Fill your HLT to the top of the HERMS coil and fill the MLT with the exact strike volume you need. Fire the system up with an HLT target only 3F above mash target. The strike will heat up through the HERMS and the MLT will be perfectly preheated. This puts the HLT at the right temp for mash recirc. You can get up and running 100% on electric. Even though it will take longer to heat, it's hands off so go eat breakfast.

This is the method I typically use however on my set-up this method requires a faster flow rate to quickly overcome the initial temp drop when the grain is added. If I mill tightly at say .030 I can't flow fast enough without channeling/ compacting the grain bed. I find .040 works best with this method as well as using rice hulls with anything sticky. I have everything setup the night before and my wife just turns the key on the panel on her way out to work and when I wake up around 9 I'm ready to just dough in and can then go back upstairs to make breakfast, shower etc until the mash is done. Cheers

 

[augiedoggy]

Great point and a great option if you have a 50amp back to back setup or are on gas but from the time I spent on kals site when I built my system majority only have a 30 amp setup that can only fire the hlt or bk one at a time and therefore can't really do that. Cheers

This is a good point. I also have a 30a setup only with a rims and in my setup this limitation doesnt exist because of careful sizing of elements, which is worth mentioning for those still looking and comparing rims vs herms.

 

[sicktght311]

For the record, i've set my mill gap at .48 with my herms system and have found NO drop in efficiency, but all the world of difference in both flow rates and lack of stuck mash/sparge, no matter how much adjuncts i use. I am consistenly 70% efficiency when i use Viking 2-row, and 75% when i'm using Briess 2-row