Leaving a thermocouple probe in fermenting beer?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

scone

Well-Known Member
Joined
Oct 28, 2009
Messages
298
Reaction score
0
Location
Boston
I am going to do some ghetto fermentation temperature control this summer by putting my glass carboy into a cooler with ice water in it. I'd like to be able to read accurate temperatures from inside the carboy, so I though about just leaving my handy type-K thermocouple inside the carboy, and running the wire out beside the stopper. It's a really flat wire so I should be able to seal around it with tape really easily. That way I can attach my multimeter to it at any time and get a really accurate read.

My question is, will the acidic wort interact with the thermocouple? It's not shielded in any kind of copper or stainless steel sleeve, so the constituent metals (nickel, chromium, manganese, aluminum) will be exposed to the wort. Anyone know if this is a bad idea?

Here's a link to the probe in question:
http://us.fluke.com/Fluke/usen/Accessories/Temperature/80BK-A.htm?PID=55348
 
I use the THS-113-372 Heavy Duty Wire Probe from this page. I also use that probe in my mash tun to monitor temps.

Sorry for showing my ignorance, but I assume you plug that into a meter of some sort? Any recommendations? And you can submerge that wire probe with no problem? My meat thermometer HATES moisture and it's nothing but a damned headache.
 
I am going to do some ghetto fermentation temperature control this summer by putting my glass carboy into a cooler with ice water in it. I'd like to be able to read accurate temperatures from inside the carboy, so I though about just leaving my handy type-K thermocouple inside the carboy, and running the wire out beside the stopper. It's a really flat wire so I should be able to seal around it with tape really easily. That way I can attach my multimeter to it at any time and get a really accurate read.

My question is, will the acidic wort interact with the thermocouple? It's not shielded in any kind of copper or stainless steel sleeve, so the constituent metals (nickel, chromium, manganese, aluminum) will be exposed to the wort. Anyone know if this is a bad idea?

Here's a link to the probe in question:
http://us.fluke.com/Fluke/usen/Accessories/Temperature/80BK-A.htm?PID=55348

Do you have a meter to plug that into? Looks like it plugs into a digital multimeter.

Use a thermocouple like that, but get a therrmowell to put it into. Click pic for link. Just slide your probe down into the metal tube. You could probably make one like this yourself by 1) drilling a stopper, 2) crimping (maybe sweating) one end of a piece of 1/4" copper tubing, flaring the other end.


 
Sorry for showing my ignorance, but I assume you plug that into a meter of some sort? Any recommendations? And you can submerge that wire probe with no problem? My meat thermometer HATES moisture and it's nothing but a damned headache.


Yes, it's a type-k thermocouple which is sort of a standard that many meters will accept. I personally use one of these, but if you wanted to automate it at some point in the future, you can find plenty of temperature controllers that take type-k connectors as well.
 
I wouldn't worry about it at the pH of a normal beer. Stainless is generally only susceptible to strong mineral acids, not the weaker organic acids present in beer.
 
Haha I think this thread has gotten a little sidetracked. I'm actually trying to avoid buying a stainless thermowell, and I was wondering if the k-type thermocouple itself is susceptible to breaking down in the wort. If nobody knows I might just try it and see what happens.
 
Haha I think this thread has gotten a little sidetracked. I'm actually trying to avoid buying a stainless thermowell, and I was wondering if the k-type thermocouple itself is susceptible to breaking down in the wort. If nobody knows I might just try it and see what happens.

The thermocouple I linked above is perfectly fine for extended time in the fermenter, and is a k-type.
 
The thermocouple I linked above is perfectly fine for extended time in the fermenter, and is a k-type.
weirdboy in my opinion the THS-113-372-T is a better choice, its waterproof.

Because the thermocouple bead is exposed soon or later any liquid will migrate under the insulation and create a problem (sanitizing, etc.).
The beaded wire thermocouple is best used for non liquid applications.
The thermocouple probe is the way to go if no thermowell is desired.
For direct liquid measurements I use Transition Joint Thermocouples which are available with a wide range of stainless steel tubing lengths.
Mine range from 12"-22".

Fermenter_Top_Insulation-1.jpg


To the OP, get a thermowell as suggested by passedpawn

Cgeers,
ClaudiusB
 
Back
Top