2nd Attempt At Herms

[Benno-5]

After my first attempt with became infected, i was able to iron out problems like to little water in hlt to start and I added the yeast imedeatly (there was space in my fermentation fridge this time).

I have now done 2nd attempt. It took 6 hours, and i hit the exact gravity of 1048 with 20 litres of wort! There was one small problem, i am unable to heat the mash higher that 70deg even though the hlt which the wort was being pumped through (heat exchanger) was at 78deg. I assume there must be to much heat loss somewhere inthe system, which is odd as i have lids and insulated kegs as vessels.

Therefore instead of heating the mash to 76deg (mashout) i simply sparged at 78deg. Will this cause any problems or will the sparge water at 78 deg do the same as mashout (i.e stop enzyme action)?

It smells very good and i think i might be on a winner here.

cheers

Benno

 

[ArnieW]

After my first attempt with became infected, i was able to iron out problems like to little water in hlt to start and I added the yeast imedeatly (there was space in my fermentation fridge this time).

I have now done 2nd attempt. It took 6 hours, and i hit the exact gravity of 1048 with 20 litres of wort! There was one small problem, i am unable to heat the mash higher that 70deg even though the hlt which the wort was being pumped through (heat exchanger) was at 78deg. I assume there must be to much heat loss somewhere inthe system, which is odd as i have lids and insulated kegs as vessels.

Therefore instead of heating the mash to 76deg (mashout) i simply sparged at 78deg. Will this cause any problems or will the sparge water at 78 deg do the same as mashout (i.e stop enzyme action)?

It smells very good and i think i might be on a winner here.

cheers

Benno

Hi Benno,

your beer will be fine. Mashout is not necessary to make a good beer.

How is your heat exchanger set up? Without any insulation, I typically have achieved about a 3deg C difference between HLT and what comes out of the heating coil. Can you let us know the length of (I assume) coil that is in your HLT and details about how you've routed the plumbing?

cheers, Arnie

 

[Wortgames]

It'll be fine.

Mashing out halts enzyme activity (important if you have a really specific fermentability profile in mind and it will be a while before the kettle hits high enough temperatures) and it helps to release the sugars from the grain (important to a commercial brewery or someone using a really thick mash).

A few minutes more enzyme activity while you wait for your 20L kettle to heat up will make no difference, and your mash is probably thin enough that you'll sparge without any dramas.

Most homebrewers don't bother mashing out.

 

[Benno-5]

its is a 1/2 inch copper coil about 13 metres in length. Clear polly pipe from mash tun to pump and from pump to hlt. Length of total polly pipe is about 1.5mt.

 

[MHB]

Just a thought, have you compared the 2 thermometers/sensors to echother?

One may be reading different to the other.

MHB

 

[Benno-5]

thats a good point, i will check, im pretty sure they were reading the same when i got them. I think the heat loss might be in the polly hoses.

 

[razz]

Evening Benno. From my experiences I would say the heat loss is from the hose, you could try a length and a half of armourflex from a plumbing supply. You really need to nail down that problem with the mash temps, can you describe your mash tun and hlt please ?

 

[Benno-5]

both are kegs. Mash tun has a false bottom, hlt has a copper coil heat exchanger, march pump, various hoses, copper sparge arm (copper pipe ring with holes that sits on top the grain bed). Bugger it ill go take pics and post shortly

 

[Benno-5]

Herms Setup


Mash tun with false bottom and sparge ring


side view showing mash tun left, hlt top centre, kettle right, march pump is uner milk crate


hlt


hlt showing heat exchanger and electric element.

System is all electric, kettle and hlt both have electric heating elements

 

[razz]

Nice work Benno ! Now about that heat problem. I don't know how powerful your hlt element is, but if you get the sparge water to approx 80 degrees then start to recirculate the wort the element should stay on, the sparge temp should remain about the same and your mash should slowly increase in temp. That's a lot of shoulds but I find that works best for my herms. If the element doesn't stay on then turn up the thermostat until it does. Any thoughts ?

 

[Benno-5]

i had it on and the hlt stayed at 78 and the highest the mash would go was 71. I dont have a thermostat at this stage just a finger on the switch and an eye on the thermometer. Thanks for the feedback guys

 

[oldbugman]

Not a HERMS guys, but were you stirring the water in the HLT?

 

[Benno-5]

nope, lid on hlt and mash tun

 

[domonsura]

Nothing to add about your heat loss issues (the other guys are on the money I reckon), but just wanted to comment on your good effort with your brewery. Looks good man. Insulation is the way to go!

 

[Linz]

Have you tried to get some insulation on the hoses??

 

[tangent]

just wondering how much of your heat exchange copper tube is under your mash level.
(agree, damn nice work!)
I would have thought 1/3rd of that would be above the mash?

 

[ArnieW]

Not a HERMS guys, but were you stirring the water in the HLT?

I think this is an important point. You were measuring 78 in the HLT but it could have been a hotspot.

Next brew, stir the water a bit and see what happens. Is your temp probe close to your heating source?

 

[Doogiechap]

G'day Benno,
I found that using my heat exchanger for my Herms was not giving me enough flexability in getting my sparge temps so it's a dedicated unit now and I have a separate HLT. I run the heat exchange about 2-3 above my mash temp to maintain the desired temp in the mash then crank it up for mashout/ sparge. The rate of temp change is quite slow so I find that by adding the 90 sparge water (Batch sparge) will actually help raise the temp of the Herms Heat Exchanger to my target of about 75. I have an 1800 watt element in my heat exchange and about 6m of 12mm copper sitting in about 16L of water. My Mash Tun is a gatorade esky and hoses are 18mm reinforced food grade with no insulation. I will eventually insulate my heat exchange to improve efficency. I gleaned a lot of good info on running my herms setup from here.
Cheers
Doug

 

[oldbugman]

I think it's that site which contains some good info on sizing the size of your heat exchanger to a heat source(electric element) from memory he comes up with the maths saying you need a turkey burner(140,000BTU) burner for a full sized keg and as a result he sized his much smaller to account for using a element

 

[oldbugman]

Check to make sure I wasn't making all this up

After some quick calculations, I determined that about 2000 Watts was the max power I wanted to deal with as far as heating elements. This makes the current draw about 16 - 17 Amps. Any more than this and I'd probably trip a breaker. So now, I needed to select the actual size of the container. I first thought that a 1 gallon paint can would be a good vessel. This seemed to be a practical size and something I could lay my hands on pretty easily. It was, until I tried to put standard sized heating elements in it and found that the tips of the elements stuck up above the rim of the can. That wouldn't do at all. The whole element needs to be submerged otherwise the element cannot dissipate it's' heat and it will burn up. I needed a slightly taller can. I was able to find a 5 quart container that had the same diameter as a paint can but was about 2 - 3 inches taller. Perfect. Once I put the coil in, I would end up with about 1 gallon of water. As a rough estimate of the power of the heat exchanger, you can calculate the Watts/gallon of water. In my case, I had about 2000 Watts/gallon. A similar power source for a 15 gallon HLT would make the power requirement 30,000 Watts pointing out the impracticality of using the HLT and trying to quickly change the water temperature with electricity (NOTE: 30,000 Watts equates to about a 100k BTU/hr burner, which is what most people using the HLT use to heat their water, quite a coincidence, eh?). Now, due to the small mass of water of my heat exchanger, the water will cool off more quickly as heat leaves via heated wort and heat loss to the environment, however, this merely means that the elements may have to fire up a little more often - but the water will react much faster to heat input because of the massive Watts/gallon ratio. Another important aspect to heat exchanger performance is water agitation. Definitely make plans for agitating the heater water to achieve optimum heat exchanger performance. This is basically something to constantly stir the water. I have details on my methods for this on the Heat Exchanger page. This makes a huge difference in your heat exchanger efficiency, don't overlook it.

http://sdcollins.home.mindspring.com/HERMSDesignSpecs.html