eHERMS efficiency all over the place

[BigJay13]

I've switched over to eHERMS in 15 gallon pots. Ive got a slotted false bottom in my MT and the blichman autosparge. My current process is to underlet into the MT, stir once, begin the recirculation once I transfer the sparge liquor from the BK to the HLT, wait for the temps to stabilize at mash temp and then start my timer. I flow the wort slower than the videos from Kal and theelectricbrewery during the recirc but otherwise follow those steps. I transfer to the BK at a rate of 1 quart per minute.

I've consistently been getting efficiencies in the high 60's with hydrometer and refractometer. I've tried stirring a lot, stirring a little, and not stirring. I've used rice hulls, I've tried speeding up the recirculation and slowing it down. I usually mash for 45 minutes then increase to 165 over 15 minutes. It usually takes 20 to increase to 165 and I don't start the clock until I hit my mash temp so the total mash is probably longer.

On my old igloo cooler set up I would get mash efficiencies in the low 90's every time. It made it really easy to create recipes. One time on this system I got a mash efficiency in the 80s--it seems to happen on my German pilsner which has a lower SG. Is the reduced efficiency an effect of doing larger mashes? For instance, in my most recent beer the grist was:

21.75 lbs Maris Otter
1.75 White Wheat
.75 C40
1 LB Dextrose

I got a SG of 1055 13.5 gallon pre-boil wort and a mash efficiency of 73%. (total BH efficiency was 68%). In the videos Kal posts and on his website he's getting in the 90s IIRC.

One thing I want to do that I'm wondering if it will make a difference is to create a sparge arm so the mash is being recirculated evenly over the top of the grain bed. I wonder of the recirculating just through the 5/8 hose is causing channeling, then when I sparge the channeling continues. I have never noticed any dough balls when I empty the MT.

Any thoughts are appreciated!

 

[DonT]

I have an eHERMS Kal-ish system too. I did a of bunch research to try to understand my system and landed on a few things that work for me. First of all, I don't mash to a specific time, I mash to a particular gravity in the mash. And this depends on the mash thickness I use. I use this chart. So, for instance, if you use a mash thickness of, say, 1.44 qt/lb, the gravity in the mash should land somewhere around 1.085 (I consider this 100%). I use that particular thickness and most times I hit 1.082 after about 60-70 min. I consider the mash done at that point and start my sparge.
I used the hose method for a bit (Kal's way) but found it was digging a hole in the mash and didn't like that. I was still doing some research at the time and happened upon this contraption. Bingo! I'll post pictures later when I get home, but it's made a world of difference.
So when I'm sparging, I transfer to the BK super slow and don't let the sparge water go continuously. I turn it on and off to regulate the water level to just a pinch over the grain. When the volume in the BK gets to about 1-1.5g short of pre-boil I stop the sparge completely and let it draw off what is in the grain mass to achieve my boil volume. I don't want to over sparge and transfer a bunch of thin wort over to the BK.
I hope that's clear! I'll post some pics a bit later.

Cheers!

 

[Deadalus]

Same on the design, EHERMS. I originally used a hose too in the MT and agree with @DonT about it digging a hole. It did seem to create a channel. The locline he linked is a good choice, I use this manifold in my keggle. It has clogged a time or two in the center but I think that's an issue with my false bottom and needing to recirculate briefly at the start without the manifold connected. My false bottom has a less than perfect fit and in my opinion the holes are a little too big. I get a little bit of grain underneath but once the bed is settled it's fine. Sorry I haven't been measuring my mash efficiencies but my brewhouse efficiency improved overall making the change. It wasn't drastic though. I hit mid-80s usually with some +/- variability usually due to operator malfunctions, mainly on the fly PID temperature correction without proper stabilization.

What gap are your grains milled to? Any variability in that particularly outside your control?

Ramping up to mashout is similar in length for me as well. Are you mashing at different temperatures between recipes?

I fly sparge as slow as I can with a Phil's sparge arm. I will have to turn that off at times. I would like to get it connected to a float valve such as the Blichmann autosparge. I was thinking of building one but if I have occasionally seen them used for reasonable prices so I am just waiting. You didn't mention water levels with that. Since I have only watched the promo video, do you feel that the sparge water uniformly trickles down at the settings you have? The promo mentions a slow whirlpool.

I can't decide on the mash recirculation speed myself either. The slower you go, it would seem that the rate of flow would create a greater disparity in temperature difference between the HLT and the MT. I think this because the rate of heat transfer would be slower unless the rate of flow through the HERMS coil was too fast to bring the liquid fully up to the HLT temperature. But I don't know if that's the case or if there are other considerations. You wouldn't want to pump so fast that you get a stuck mash.

I had a drastic drop in efficiency for one brew because I had switched my base malt from Briess Brewers Malt to Briess Pale Malt and the latter has less diastatic power. The particular recipe in question had a significant percentage of low power grains and adjuncts. A protein rest corrected that as well on the next iteration as did recognizing that I had inadvertently switched my base malt.

Is your PID properly calibrated? Do you have more than one thermometer to double check? A very tricky situation I have noticed for me is that my temp probe is on the out valve to the pump in my HLT. If the HLT is full of water in order to cover the coil, that means the water column is tall. I have 2 pumps and absolutely have to always run the water pump to recirculate otherwise the temp reading is off. Next, the tall water column in my opinion, even with the pump running, has temperature stratification. I have a dial thermometer somewhat lower than 1/2 up the coil. I have an instant read thermometer that I can take readings at the top. So inline temp probe on the out valve, dial 1/3-1/2 way up, instant read at top. If they are all properly calibrated, they might still show different readings due to stratification. Last however, I recently noticed my pickup tube sits under a curve in the water heater element. So I've been seeing weird fluctuations in disagreement between devices, I think due to the element firing. All this to say, you could be off somewhere with what you think is the temperature and it may be in difficult to predict in what ways. I'm going to move the pickup tube and be careful when calibrating the PID.

Just some thoughts, not everything may apply.

 

[Bobby_M]

The first bit of troubleshooting I would recommend is to take wort samples from your autosparge hose periodically throughout the mash and measure the gravity. It should be on an upward trajectory and you can also use those numbers to calculate your mash conversion efficiency prior to getting the sparge involved.

One method of determining if you have channeling is to test the recirculated wort gravity at something like 30 minutes. Then give the mash a good stir, set the recirc again and test the gravity. If you get a sharp rise in gravity, the grainbed was "channeled".

Note that the straight locline links can be pressed on to the barb of the autosparge so you get the best of both worlds. You just have to cut one of the straight links in half and discard the larger piece. That will press on with a pair of channel locks.

 

[BigJay13]

Thanks for the replies everyone. I picked up the locline just now (thanks Bobby). The mill gap is the width of a CC. I'm wondering about the raw ingredients themselves. I haven't checked the diastatic power between Wyermann Pils and MO I have. I'll start sampling the mash gravity every 10 minutes or so and graph it out, as well as the 30 minute stir to see what I get. The PID is correct and has been corroborated by another thermometer. I run the pump in the HLT to circulate that water during the mash. I typically mash between 148 and 152. I like my beers to finish out nice and dry. The only thing I need to do is check my hydrometer and make sure that is correct. Even if that isn't correct I doubt it is off by 10 points like my efficiency is. I'm guessing there is channeling happening.

 

[doug293cz]

Lots of good advice already, especially from @DonT about measuring SG during the mash.

How are you measuring volumes? If your volume measurements have errors, those will throw the efficiency calculations off. How did you calibrate your volume measurement method? Did your measurement method change when you changed systems?

Brew on

 

[BigJay13]

Lots of good advice already, especially from @DonT about measuring SG during the mash.

How are you measuring volumes? If your volume measurements have errors, those will throw the efficiency calculations off. How did you calibrate your volume measurement method? Did your measurement method change when you changed systems?

Brew on

I have a very fancy piece of PVC that I notched gallon marks for 13 and 13.5 gallons. I shoot for pre boil volume of 13.5 gallons. I used a quart measuring cup to get the gallon marks. It's how I did it in the old system too--although that one I had a sightglass on--which I will probably add to this one at some point. The fermenter is an allrounder that has a sticker on it with all the volume measurements. That has not been calibrated. I think the main thing is channeling and not allowing the mash to fully convert.

 

[DonT]

Here's what I put together for my sparge line. I vary the number of straight pieces to get it to sit almost on top of the grain. Use the mash volume to get it right.

Take a close look... I alternate the direction of the nozzles to cover more area

 

[BigJay13]

Here's what I put together for my sparge line. I vary the number of straight pieces to get it to sit almost on top of the grain. Use the mash volume to get it right.

View attachment 782270

Very cool. My mash volume is usually near the autosparge so I probably won't need the straight sections but it's good to know there is an alternative if it doesn't fit. Good idea on alternating the directions! I probably wouldn't have thought of that.

Take a close look... I alternate the direction of the nozzles to cover more area

 

[doug293cz]

I have a very fancy piece of PVC that I notched gallon marks for 13 and 13.5 gallons. I shoot for pre boil volume of 13.5 gallons. I used a quart measuring cup to get the gallon marks. It's how I did it in the old system too--although that one I had a sightglass on--which I will probably add to this one at some point. The fermenter is an allrounder that has a sticker on it with all the volume measurements. That has not been calibrated. I think the main thing is channeling and not allowing the mash to fully convert.

A dip-stick is a perfectly good way to measure volume, and can be accurate to about a 1/10th of a gallon if calibrated well. An actual ruler can do better than that, once you correlate distance to volume for your vessel. It doesn't appear that you have enough volume markings on your dip-stick to make all the measurements needed: strike water volume, pre-boil volume, and post boil volume at a minimum (add sparge volume if you should ever batch sparge.) Accurate fermenter volume is needed if brewhouse efficiency is important to you (I tend to only worry about conversion efficiency, lauter efficiency, and mash efficiency (= conv eff * lauter eff.)

Did you check the calibration of the measuring cup you used? Weight is the best way to do it (1 gal weighs 8.33 lb @ 68°F, so 2.08 lb/qt.) Measuring out 52 - 54 1 qt volumes can also be error prone if you are not extremely careful.

You are correct that low conversion efficiency and channeling are the two things most likely to cause low efficiency when fly sparging. Batch sparging does not suffer from channeling, so trying a batch or two that way could be enlightening. A well conducted fly-sparge will have better lauter efficiency than even a triple batch sparge, but is more error prone than a batch sparge.

Brew on

 

[BigJay13]

A dip-stick is a perfectly good way to measure volume, and can be accurate to about a 1/10th of a gallon if calibrated well. An actual ruler can do better than that, once you correlate distance to volume for your vessel. It doesn't appear that you have enough volume markings on your dip-stick to make all the measurements needed: strike water volume, pre-boil volume, and post boil volume at a minimum (add sparge volume if you should ever batch sparge.) Accurate fermenter volume is needed if brewhouse efficiency is important to you (I tend to only worry about conversion efficiency, lauter efficiency, and mash efficiency (= conv eff * lauter eff.)

Did you check the calibration of the measuring cup you used? Weight is the best way to do it (1 gal weighs 8.33 lb @ 68°F, so 2.08 lb/qt.) Measuring out 52 - 54 1 qt volumes can also be error prone if you are not extremely careful.

You are correct that low conversion efficiency and channeling are the two things most likely to cause low efficiency when fly sparging. Batch sparging does not suffer from channeling, so trying a batch or two that way could be enlightening. A well conducted fly-sparge will have better lauter efficiency than even a triple batch sparge, but is more error prone than a batch sparge.

Brew on

Good idea on the weight measurement. I didn’t think about that. I have a sight glass on the HLT that has measurements done by the same method. I’m not too caught up on exact numbers, but not being remotely close to the expected OG us driving me nuts.

 

[doug293cz]

Good idea on the weight measurement. I didn’t think about that. I have a sight glass on the HLT that has measurements done by the same method. I’m not too caught up on exact numbers, but not being remotely close to the expected OG us driving me nuts.

10% off on a volume measurement will mean you are at least 10% off on an efficiency calculation that uses that volume measurement. I'm not a big supporter of efficiency for efficiency's sake, but if you want to know where you stand, you need reasonably good measurements.

Brew on

 

[BigJay13]

So after a couple brews these are the things I found:

For whatever reason, recirculation seems to slow down the conversion when compared to my old igloo cooler. I mashed for 90 minutes today (vs 45-60 as that is what I always did with the cooler) and got almost 90% mash Eff. Brewhouse was 76% instead of 65% so I'm happy with that. I used the locline shown above but need to figure out a better way to mount it. It does fit over the nipple of the autosparge with the large part cut off, but it hangs into the mash once it is full of liquid. I wrapped a bunch of plumbers tape around the nipple to make it stay in place and that helped some.

I stirred after 30 minutes and got a 5 point jump within a few minutes--I'm assuming that is a result of channeling. My next brew I'm going to try the old single infusion and I won't recirculate for an hour and see what happens. It kept from 1060 at 60 minutes to 1080 at 90 and that's when I cut it off.

I have not had the time/motivation to check my volume measurements in a more accurate way. I am going to put a site glass on may BK some day and when I do that I will measure out water on a scale to make my measurements.

 

[boondocksaint]

I have an eHERMS Kal-ish system too. I did a of bunch research to try to understand my system and landed on a few things that work for me. First of all, I don't mash to a specific time, I mash to a particular gravity in the mash. And this depends on the mash thickness I use. I use this chart. So, for instance, if you use a mash thickness of, say, 1.44 qt/lb, the gravity in the mash should land somewhere around 1.085 (I consider this 100%). I use that particular thickness and most times I hit 1.082 after about 60-70 min. I consider the mash done at that point and start my sparge.
I used the hose method for a bit (Kal's way) but found it was digging a hole in the mash and didn't like that. I was still doing some research at the time and happened upon this contraption. Bingo! I'll post pictures later when I get home, but it's made a world of difference.
So when I'm sparging, I transfer to the BK super slow and don't let the sparge water go continuously. I turn it on and off to regulate the water level to just a pinch over the grain. When the volume in the BK gets to about 1-1.5g short of pre-boil I stop the sparge completely and let it draw off what is in the grain mass to achieve my boil volume. I don't want to over sparge and transfer a bunch of thin wort over to the BK.
I hope that's clear! I'll post some pics a bit later.

Cheers!

DonT,

With mashing to a particular gravity, does this change depending on your intended SG (pre-boil) and expected FG (post fermentation)?

Thanks.
~JG

 

[DonT]

DonT,

With mashing to a particular gravity, does this change depending on your intended SG (pre-boil) and expected FG (post fermentation)?

Thanks.
~JG

If I understand you correctly....
Mashing influences SG and FG, but not the other way around. You have to conduct your mash and sparge to get to the pre-boil you planned on. And then also manage the boil....

Mashing to a particular gravity is really just getting a good conversion... ~95% is what I shoot for. Temp, grain volume and to a certain extent type of grain, influence this.

This is all recipe building stuff.

I hope that explains what you were asking.

 

[DonT]

I'm actually in the process of refining my volume measurements. I just bought this scale to weigh the water/wort. I was having boil eff. issues and need to be sure of my volumes.