Electrified Mash Tun - let's go there again

OK, so I've been trying to recreate the wheel with a novel way to heat my mash tun. I run with an Electric HLT and Keggle and I have been holding and/or boosting the heat with regular additions of hot water (from the HLT - 212F).

I have seen some discussing placing another ULWD element below the false bottom but that won't work for my set-up and I don't like how inaccessible the elements are in a RIMS tube.

What I'm wondering if anyone has tried adding a 5500 ULWD element in the MLT wired at 110V so it's in the 1375W range (instead of 220V). Since this would take the watt density down to 12.5 watts per inch (from 50 wpi) it seems like I could get away with minimal stirring or recirculation and still avoid scorching. A side benefit might be to get a pseudo-decoction flavor with no recirculation or stirring at all.

If my math is correct, (and it always is ) I will only need to run the element for 3-5 minutes of every 15 to hold a steady mash temp when in the 150F range and if I leave it on I can raise the mash temperature about 5 degrees for 6 minutes it runs. If so, I would combine the mash-out step and recirculation into a single 15-20 minute phase without having to add several gallons of boiling water, filling my MLT to the brim, and limiting the maximum size of my grist.

Any thoughts, suggestions, or incendiary remarks are welcome.

- Cheerio

My thoughts are heat is carried away from the element in a normal installation by the movement of the liquid. In the mash you are not going to get this movement so you could end up with a hot spot in the middle and cold around the outside.
Why are you dismissing the RIMS so quickly, plenty have built them around triclover fittings making element removal relativly easy (Brewers hardware / brewing hardware?) have a off-the-shelf RIMS tube with triclovers.

I like the rims setup with the tri-clovers, just not the price tag.

For the heated mash I have everything but a $20 heater element. Also I should mention that I have installed a stirring arm that is operated through the lid of MLT. I left the paddles up high enough that they would not interfere with element, so they get the mash moving around pretty well.

The only way to know is to try it! You say your math is always correct, so on to victory with you!

OK, If it's a horrible failure, what should I put in the 1-3/8" hole left behind? I already have a thermometer and an outlet, and I don't see the need or function for a MLT sight glass.

Or will I have created another e-keggle?

Onward to science!

The site glass is useful for fly sparging. Thats how I justified mine on my old brewkettle -> now mash tun

hustlebird said:

The site glass is useful for fly sparging. Thats how I justified mine on my old brewkettle -> now mash tun

Click to expand...

I fly sparge, and I like to learn new tricks (and buy new stuff). How does the sight glass help with the sparge and where is it place in relation to the drain?

Anytime I have put grains near an element I have gotten scorching. Whether hd or ulwd. Maybe just my bad luck. Now I have a mlt with an element in it that helps me heat easily to strike temp then I turn it off. I actually like this design now although it came from a previous failure.

Thanks for the input on scorching HarkinBanks...maybe I will try a test run in an old pot with a few pounds of grain before I muck-up an entire brew day.

Out of curiousity what qt/lb ratios were you working at? I'll probably run a test at 1qt/lb since that is about as low as I ever go, but usually I target 1.5 to 2.0 qt/lb for main mash.

I tried all sorts of configurations with it, using a false bottom on top of the element, using a voile curtain directly on the element, using the curtain on top of the false bottom (that was the worst, got an air pocket and popped the element). I recirculated with a pump, tried no pump and stirred and turned on and off, and got scorching just about every time. I finally gave up. Ratios were always 1.5 or higher. This is the main reason I went to a HERMS setup. I will never let grain come in contact with an element during a mash again. And that terrible smell of burnt grain will forever be with me.

Got it, I'll definitely give this some more thought before putting another big hole in my MLT.

Maybe if I add a ring of 5/8" ID copper tube (holds about 2oz per foot) near the bottom of the tun and run boiling water through that. At least it won't have the possibility of scorching...

My gut says it will work, but my brain wants more math determine the rate of heat transfer, sizing, etc, etc.


"Alright brain, I don't like you and you don't like me, so let's just get through this and I can get back to killing you with beer." - Homer Simpson

OK, my shaky grasp on thermodynamics tells me that a 10' coil (3 laps) of 1/2" OD copper tubing with boiling water pumped throught it (form HLT to HLT) should be able to raise the temperature of a 10 gallon mash from 150 to 158 or 158 to 165 in about 20 minutes. This is like a 1,250W element at 8 watts per inch (wpi).

10' of 5/8" OD would simulate a 1,575W element, also at 8 wpi and only take 15 minute for the same steps.

6' of 3/4" OD or 4-1/2' of 1" OD would be roughly equivalent.

I'm trying to picture this.

If you're putting the element in the MLT, then recirculation is a must (to avoid hot spots while the rest of the mash is too cold). If you're recirculating anyway, why not go with HERMS instead of RIMS? I used an old immersion chiller, and put the HEX right in the HLT, so the costs was nil except for some disconnects.

(One of the things I hate in this forum is when people say, "I am having trouble bottling" and other people answer "Kegging is the answer". I detest when someone has a system and it's dismissed and the answer is to get something else. I sure hope I didn't just do that to you! That's not my intention at all- I'm trying to visualize what you're doing and help come up with a way to make it work).

Yoop-I think he wants to put a copper coil in the mash tun and pump boiling water through it to directly heat the mash, albeit with sort of an indirect heating method.

The only issue I can see with this would be variable hot spotting. You would likely need to mix the mash. I don't think recirculation alone would work well enough.

No problem, I'll try to explain my situation a little better...

I have a plate chiller that I could use as the heat exchanger but only one pump. I can filter the grain out with either the grant or a hopback/filter that I made, but ultimately I don't want the chiller to get coated with starches/protein, and then try to use it later in the day for its intended purpose.

If I had an old immersion chiller I would probably go with the HERMS. The only down side is that I can't see inside the copper tube so I would rather run hot water on the inside and wort of mash on the outside, where I can see the pipe condition.

I do have a paddle system inside the MLT: it is a shaft of stainless steel that goes through the lid and has a couple of perforated steel (like a false bottom) paddles (3" tall x 15" wide each). There is a hand crank at the top. I have a water-in port near the top of the tun so when I add water to make a temperature step I can do so without taking off the lid, but can still mix the water into the mash.

Currently I add about 2 quarts of boiling water every 20 minutes and give the mash a dozen rotations (6 clockwise, 6 counter) to maintain a constant mash temp. However, I nearly fill the tun for mashout to get it to 168F, when I'd rather save more of the water for a fly sparge and get a little more efficiency.

My HLT and Kettle are both 240V (5500W and 4500W respectively) so I am comfortable with the power side of things. I've just been wondering if I reduced the watts per inch of the heater element by 1/4 by powering down to 120V and kept the main moving with the paddles and or recirculation if I could eliminate scorching. The second, scorch proof option would be to add copper tubing coils to the tun to simulate the heater element without ever exceeding 212F.

The above calculations suggest how much copper is needed to raise the temperature to mashout in a reasonable amount of time, which - on a cost basis ($20 for 10' of 1/2" OD) is about the same as buying a new heater element.

At this point I was thinking I could run a test with my e-Kettle and the spent grain at the end of my next brew day (~5/1/13) - maybe throw some table sugar in there to approximate the proper chemistry/OG of a mash. Since the Kettle is the same configuration as the MLT (including thermometer and false bottom) I can put the theory to test without making any expensive or permanent modifications or ruining an otherwise perfectly good brewing day. If these tests fail I will look more into the other heating options.

I just wanted to see if any other poor fools had already try this and/or had advice to give before I jumped in head first.

...end rant.

If it helps, I'll post some pictures this weekend of the various components listed above.

Also...whatever the question, kegging is always the answer!

KegWrangler said:

If it helps, I'll post some pictures this weekend of the various components listed above.

Click to expand...

That would help, but I think I'm picturing it now. I assume you're CIP? It'd be a bit of a challenge to really clean the MLT/HEX/ otherwise, especially if you're adding copper coils.

Uh, sure I CIP; doesn't everybody?

Mostly my cleaning involves backflushing the chiller with water at~100psi, rinsing out the pump, and MLT then recirculating hot PBW from the MLT throughthe pump and chiller then back into the MLT while I scrub aggressively with a kitchen brush. Sometimes I will recirculate with starsan after rinsing to get a little acid into though hard to reach places.

The kettle gets pretty much the same treatment, with special attention paid to the element - which must be returned to its original "factory black" color before being put away.

Here is a kindergarden quality drawing (you can put it on your fridge!) of what I have versus what is planned.

Then new heater element is in red. I am drawing it as it I have pryed the two sides apart into a wye shape to spread the load across more mash area. In practice the element will sit about 1/2" below the lower paddle so as not to get scratched up.