First brew with my ebrew rig complete!

[augiedoggy]

The only time you would see benefit to stir the HERMS/HLT water is during the initial heating of the mash strike water (assuming a single element system like mine) or when performing a mash step temp increase.

In any other instance, the total volume of water in the system is going to reach an equilibrium and the PID is going to pulsate to maintain that delta, recovering for the totality of heat losses.

While this makes logical sense that it would be much worse during the initial warm up period I respectfully disagree with it not mattering once temp is reached as I found this not to be the case in my setup... My herms temp would jump whenever I stirred my HLT even during the middle of the mash and the temp always fluctuated a bit because of this.. The result was it just wasnt very stable.

 

[cantrell00]

While this makes logical sense that it would be much worse during the initial warm up period I respectfully disagree with it not mattering once temp is reached as I found this not to be the case in my setup... My herms temp would jump whenever I stirred my HLT even during the middle of the mash and the temp always fluctuated a bit because of this.. The result was it just wasnt very stable.

That's because every time you stirred you disrupted what the PID was accustomed to see re; temp input vs the temp it was seeing in response to you stirring the HLT.

The PID fluctuations were a measurement of those differences.

Were you step mashing in this scenario? Why did you feel the need to stir the HERMS/HLT water?

 

[BrunDog]

Rims is less forgiving if the system isn't designed and operated correctly... A stuck pump or line and disaster can strike (which is why I went with the flow switch for safety in my setup.)

True. Most high performance tools make the trade between performance and usability/forgiveness.

 

[augiedoggy]

That's because every time you stirred you disrupted what the PID was accustomed to see re; temp input vs the temp it was seeing in response to you stirring the HLT.

The PID fluctuations were a measurement of those differences.

Were you step mashing in this scenario? Why did you feel the need to stir the HERMS/HLT water?

Honestly I dont remember since it was a couple years ago... Most likely because I wasnt getting steady results in my mash temp. You kind of made my point though ... If the HLT water is recirculating the temps are even and an even consistent temp is applied to the entire length of the herms coil which would provide tighter temp control no? Rather than the temps being higher down near the element than they are in other areas of the coil and constant fluctuations as the liquid temps keep shifting. inconsistent uneven temps are going to cause uneven inconsistent results as far as I can reason. Also the liquid near the element could be a lot higher in temp than the liquid near my temp probe making the temp control pretty unreliable and hard to nail down.

 

[cantrell00]

Honestly I dont remember since it was a couple years ago... Most likely because I wasnt getting steady results in my mash temp. You kind of made my point though ... If the HLT water is recirculating the temps are even and an even consistent temp is applied to the entire length of the herms coil which would provide tighter temp control no? Rather than the temps being higher down near the element than they are in other areas of the coil and constant fluctuations as the liquid temps keep shifting. inconsistent uneven temps are going to cause uneven inconsistent results as far as I can reason. Also the liquid near the element could be a lot higher in temp than the liquid near my temp probe making the temp control pretty unreliable and hard to nail down.

Not necessarily.

If the HLT is covered, the only thing the recirc pump is doing is averaging out the entire temp of the volume of water. It would also depend on where you are measuring. In my scenario the measurement is at the MLT return but the same would be true if measuring immediately at the HLT exit. Measuring at the MLT exit would be of little consequence either way.

The PID is going to see a temp regardless so if for example the bottom of the coil is 155 degrees & the top of the coil is at 148, the temp out of the coil is going to be an eventual average of that temperature gradient on the wort that is passing through it.

Stirring the water would only even out the average temperature of the total volume of water. Assuming that the entirety the water volume in the system has reached an equilibrium.

I would doubt that there would be significant difference in the temp of the wort as it exits the coil with or without re-circulation once everything has settled.

Running a circulation pump through non insulated lines in very cold temperatures is going to introduce heat losses also. Not much, depending on the distance, speed of travel, etc but you do lose heat there none the less.

Basically, a re-circulation loop can make the brew day more efficient, not more accurate.

 

[stevehaun]

You guys are making this way too complicated. I am controlling the temp of the wort returning to the top of the mash by increasing or decreasing the temp of the water in my HLT. This is the same as a RIMS. I don't care about the temp of the water in my HLT; I care about the temp of my wort as it returns to the top of the mash. The thermocouple feeding back to the PID controlling the elements in my HLT is in the wort returning to the top of the mash. I do not directly control the temp of the water in my HLT. I do know that the temp of the water in my HLT is 2-4F higher than the temp of the wort returning to the top of the mash, but it really doesn't matter if it is a 1 degree or 8 degree gradient. Most folks control the temp of the water in their HLT and hope their wort temp is correct. I personally think that is ass backwards.

 

[stevehaun]

With a HERMS you basically have two choices:
1. Control the temp of the water in the HLT (thermocouple or rtd in HLT) and hope your wort temp is where you want it.
2. Control the temp of the wort as it returns to the top of the mash (thermocouple or rtd inline at return to mash). With this approach you do not need to know the temp of the water in the HLT.

 

[iijakii]

The common approach is that by controlling your HLT temp you arent subject to swings and stratifications, you can exactly predict what temp the wort exiting will be (my mash as a whole had 1F temp loss systemwide, set HLT one degree higher than mash point). Common thought is by measuring wort-return temp you will have swings because the HLT might overshoot etc.

I know my HLT had pretty severe stratification without mixing, but I'm curious now if that wouldnt have made a difference or not. I admit to doing my rig that way just following Kal and the herd. If youre not seeing any flucation in the wort return temp that's sweet, cuts out the need for the second pump.

 

[stevehaun]

My controlling thermocouple is between the HERMS coil and the mash tun. I also measure wort temp as it leaves the bottom of the mash tun. I don't predict what my wort temp is, I control it.

 

[cantrell00]

You guys are making this way too complicated. I am controlling the temp of the wort returning to the top of the mash by increasing or decreasing the temp of the water in my HLT. This is the same as a RIMS. I don't care about the temp of the water in my HLT; I care about the temp of my wort as it returns to the top of the mash. The thermocouple feeding back to the PID controlling the elements in my HLT is in the wort returning to the top of the mash. I do not directly control the temp of the water in my HLT. I do know that the temp of the water in my HLT is 2-4F higher than the temp of the wort returning to the top of the mash, but it really doesn't matter if it is a 1 degree or 8 degree gradient. Most folks control the temp of the water in their HLT and hope their wort temp is correct. I personally think that is ass backwards.

I have the same setup as you & agree. Usually a delta of 2-3 degrees of HLT water temp & wort temp as it returns to the MLT.

 

[cantrell00]

The common approach is that by controlling your HLT temp you arent subject to swings and stratifications, you can exactly predict what temp the wort exiting will be (my mash as a whole had 1F temp loss systemwide, set HLT one degree higher than mash point). Common thought is by measuring wort-return temp you will have swings because the HLT might overshoot etc.

I know my HLT had pretty severe stratification without mixing, but I'm curious now if that wouldnt have made a difference or not. I admit to doing my rig that way just following Kal and the herd. If youre not seeing any flucation in the wort return temp that's sweet, cuts out the need for the second pump.

Yup.. Mine operates this way. I only turn that re-circulation HLT pump on when I am heating the strike or stepping.

I tried it this weekend just to verify. Once the system temp settled (HLT/MLT mash), the PID was just as stable with or without that re-circulation pump running.