DIY Mashtun Thermowell - easy and cheap

[KuntyBrew]

you may want to stay away from copper during and post fermentation

quoted from http://***********/component/resour...November 2007/1149-metallurgy-for-homebrewers
"Copper is a double-edged sword in brewing. It is beneficial before fermentation, but detrimental afterwards. Copper ions react with the hydrogen sulfide produced during fermentation and reduce it to insoluble copper sulfide, which is left behind with the trub and yeast cake. Switching to all stainless steel brewing equipment can lead to noticeable quantities of hydrogen sulfide and sulfur off-flavors and aromas in the beer. The use of copper wort chillers will provide all the copper necessary, as will including a short piece (1 inch) of copper tubing in the boil.

Copper is a problem post-fermentation because it catalyzes staling reactions, including the production of hydrogen peroxide and can oxidize the alcohols to aldehydes. Finished beer should not be stored in contact with copper, although serving beer with copper tubing in a jockey box should not be a problem, because of the short contact time immediately before serving. "

that being said I am sure some people have done this and had good results see this thread and i am sure there are more.
https://www.homebrewtalk.com/f11/homemade-fermenter-thermowell-268794/

 

[HibsMax]

Thanks and f***. I'll switch my fermentation bucket lid back to the non-modified version and see if I can get some steel tubing in the right size. Or maybe I can modify the lid so that just the thermometer is in the beer e.g., small hole and grommet with thermometer probe fitted snuggly in that.

Looks like I need to read some more about this. The copper thermwell has only been in place for about an hour so I doubt it's had time to do any damage.

Thanks again for the heads up.

EDIT : now I just need to find where I can get about 1' of 1/4" SS tubing. LOL. Maybe I'll just forget it for now.

 

[phoenixs4r]

Thanks and f***. I'll switch my fermentation bucket lid back to the non-modified version and see if I can get some steel tubing in the right size. Or maybe I can modify the lid so that just the thermometer is in the beer e.g., small hole and grommet with thermometer probe fitted snuggly in that.

Looks like I need to read some more about this. The copper thermwell has only been in place for about an hour so I doubt it's had time to do any damage.

Thanks again for the heads up.

EDIT : now I just need to find where I can get about 1' of 1/4" SS tubing. LOL. Maybe I'll just forget it for now.

Once upon a time when I though of doing this I think I found a thread that used a stainless steel line from a toilet for the fermentation chamber. If j stumble across the thread again I'll let u know.

 

[krazydave]

I saw small 8-10" sections of stainless tubing at OSH just the other day. If you have one near, it might be worth checking out.
It was on the front of the rack with all the other metal stock.

 

[HibsMax]

Once upon a time when I though of doing this I think I found a thread that used a stainless steel line from a toilet for the fermentation chamber. If j stumble across the thread again I'll let u know.

I saw small 8-10" sections of stainless tubing at OSH just the other day. If you have one near, it might be worth checking out.
It was on the front of the rack with all the other metal stock.

Thanks, guys.

I don't know what OSH is but I am guessing that the H is for Hardware.

I'm not going to stress too much about it. Actually, not at all, but I will get around to it at some point. The whole reason for me doing this is for me to find out what the internal fermentation temps are for different beers and chart that along with ambient temperature, just to see what numbers I get. I've read that ferm. temp. can be as much as 5-10 F higher than ambient but my LHBS says that it's closer to 2 F. I may as well find out what the actual temp is if I can, without compromising my beer.

 

[brewmaster89]

I will be adding this to my MLT when it arrives in the mail. Hoping for this week so I can use it this weekend.

 

[nduetime]

Walker...would there be any drawbacks to adding the thermawell to the lid? I was thinking of using my long stem thermometer that came with my old turkey fryer with a setup like this. Since the lid needs to be off when stiring anyways, that would eliminate the need for caution when stirring. My mash tun is a 3 gallon rubbermaid round cooler for my 2.5 gallon batches. I think the thermometer would reach down to the grainbed. This would also elimate the risk of leaking into between the cooler walls. Ideas?

 

[Walker]

Walker...would there be any drawbacks to adding the thermawell to the lid? I was thinking of using my long stem thermometer that came with my old turkey fryer with a setup like this. Since the lid needs to be off when stiring anyways, that would eliminate the need for caution when stirring. My mash tun is a 3 gallon rubbermaid round cooler for my 2.5 gallon batches. I think the thermometer would reach down to the grainbed. This would also elimate the risk of leaking into between the cooler walls. Ideas?

I don't see any problem with putting a thermowell down through the lid. I think your bigger issue might be the accuracy of those turkey fryer thermometers. I've got several of them and there isn't a one of them that is accurate.

I can calibrate them so that they are pretty close between 145 and 160, but those things, in general, suck ass.

 

[nduetime]

I don't see any problem with putting a thermowell down through the lid. I think your bigger issue might be the accuracy of those turkey fryer thermometers. I've got several of them and there isn't a one of them that is accurate.

I can calibrate them so that they are pretty close between 145 and 160, but those things, in general, suck ass.

Any suggestions on a more reliable thermometer that is roughly the same length?

 

[Walker]

Any suggestions on a more reliable thermometer that is roughly the same length?

You can get 12" K-type thermocouples and thermometers, but you're looking at paying $75 or so for your thermometer at that point.

What I used to do before putting the thermowell in my mashtun was use one of the cooking thermometers that had the temp probe on a long lead, like this:

You can get those at Target or WalMart for like $10-$15.

Put a small hole in the lid and feed the wire through it, and drop the probe into the grain bed. You don't even need the thermowell at that point. Just be sure to keep the wire out of the liquid and only let the probe get submerged.

My probe thermometer like that started acting wonky on me so I put the thermowell in and used my trusty short-probe thermometer.

 

[nduetime]

Well I already have something very similar to the one you linked. However, my probe won't reach but 2-3" into the bed. My concern is that it might be more accurate if it were embeded more into the bed than that. Wouldn't the thermowell act more like an extension for the probe/thermometer providing a more consistent reading over the whole grain bed, provided it was long enough?

 

[Matteo57]

subscribed

 

[boneman]

This is exactly what I have been looking for. The brass compression coupling was the solution I needed. I had been planning to use a chrome water supply line. I like the copper better... a little easier to work with.

 

[dozer5454]

I put this thing together last week then brewed over the weekend. I had a digital candy thermometer that slid in perfect. This thing worked amazing. Thanks for the write up.

 

[Rbeckett]

Duda diesel has a stainless6 or 7 inch well with 1/2 pipe thread for like 16 bucks on Ebay. I got one in about 4 days and it is excellent workmanship. Even came with a cable clamp to secure the TC cable when you slid it to the bottom. I'm very satisfied with it. No copper or brass in my brew!!! Just sayin...

Wheelchair Bob

 

[rodduley]

Wheelchair Bob,Can you post a link to the well you are describing?

 

[mrklueber]

Wheelchair Bob,Can you post a link to the well you are describing?

Well, I'm not Wheelchair Bob, but the link is http://www.dudadiesel.com/choose_item.php?id=pipesert.

 

[Rbeckett]

Wheelchair Bob,Can you post a link to the well you are describing?

Sure here ya go. I bought one last week to use in my ale pail and I just drilled a hole, installed a grommet and slid it in with keg lube. Works perfectly and holds my wort at 18 Degrees C with the STS-1000 controller and a 2 dollar K type TC.. Heres the link:

http://www.dudadiesel.com/search.php?query=thermowell

Hope this helps, it's all stainless and very well constructed.

Wheelchair Bob

 

[theCougfan97]

I used this design in my cooler. The only difference being I placed the thermowell below my false bottom. During its first brew day I found the temp readings to be about 20 degrees below where they should be. Anybody know why? Do I need to move it up to the center?

 

[djrebello]

what i did was the same as the original idea you had, crimp de copper tubing to seal it, but instead of adding a compression or flare fitting i just added a silicon hose (about 1") to use as a bypass to a hose barb fitting and you can just add tha washer silicone o-ring to seal from outside the mash tun. And that gives you the versatility to take the copper tubing on and off becuase it´s attached with the silicone hose. Easy for cleaning etc. Hope this might work for you guys Cheers!

 

[rmarshall100]

Do y'all find that your mash temperature wanders around? I use a cooler as an MLT and that sucker stays where it starts. Once I mash in and everything comes to equilibrium, it is rock solid until I drain it an hour later. I have never heard of any cooler losing more than a degree Fahrenheit in the course of an hour.