thoughts on leaving a thermometer probe in fermenter

[mikerobrewer]

I have been thinking about investing in a wire probe thermometer to get a more accurate reading of my temperatures during fermentation. My thinking is I would put a small hole in my fermenter lid (I use 6 gal plastic buckets) with a small stopper/bung in it and thread the wire/probe through that so that it sits in the wort. Just curious if there may be any issues/side effects of having it sitting in there for a couple weeks. Thoughts?

 

[PhelanKA7]

I have been thinking about investing in a wire probe thermometer to get a more accurate reading of my temperatures during fermentation. My thinking is I would put a small hole in my fermenter lid (I use 6 gal plastic buckets) with a small stopper/bung in it and thread the wire/probe through that so that it sits in the wort. Just curious if there may be any issues/side effects of having it sitting in there for a couple weeks. Thoughts?

I think as long as it's properly sanitized and there are no porous looking welds going into the wort you should be fine.

 

[BigFloyd]

Why?

I simply tape my temperature probe to the side of the bucket and insulate it from the ambient air so as to get a good reading to operate the temp controller.

Of course, at the most active point, it's running a few degrees hotter in the middle of the batch which is why I have it set at 67*F (that's for this batch using Windsor - I've run it as low as 55*F using Nottingham).

I wouldn't be willing to increase the risk of contamination, however so small, just to get a reading from the core of the batch vs. the edge.

 

[mikerobrewer]

I don't have a temp controller at this point so I would like to get the most accurate reading I can so that I know what measures, if any, I need to take to keep it at optimal temp.

 

[BigFloyd]

I don't have a temp controller at this point so I would like to get the most accurate reading I can so that I know what measures, if any, I need to take to keep it at optimal temp.

You can either use a stick-on thermometer or one of those cool little infrared temperature guns. No need to put things inside your wort to measure temp.

A good rule of thumb is to ferment ales in a place that's in the mid 60's ambient temp. If you don't have such a place, you'll need to take some steps to cool the fermenter, especially during the exponential growth phase of the yeast (first 4-5 days or so). I use 2 freezers controlled with STC-1000 digital dual-temp units. Some folks use other methods that I've never bothered with. I like to be able to set my temp as I want it and not have to mess with it all the time.

Keep in mind that a fermentation during its most active phase can generate some pretty significant heat. The one I have going on right now is 7 degrees higher (measured on the side of the bucket) than the ambient air inside of the freezer it's in.

 

[mikerobrewer]

I have a stick-on thermometer on the side of it right now. I have it sitting in my kitchen a few feet from my thermostat (figured that would give me the most accurate estimate for ambient temp near the fermenter). Currently the thermostat says the inside temp is 72 and my stick-on is showing both 66 and 70, so you figure about 68.

The reason I was thinking of the probe was so that I would be able to simple power on the digital display and see what my wort was actually at instead of opening my fermenter to measure and risk contamination. Maybe I'm just being too anal about it.

 

[barnumbrewing]

I have a stick-on thermometer on the side of it right now. I have it sitting in my kitchen a few feet from my thermostat (figured that would give me the most accurate estimate for ambient temp near the fermenter). Currently the thermostat says the inside temp is 72 and my stick-on is showing both 66 and 70, so you figure about 68.

The reason I was thinking of the probe was so that I would be able to simple power on the digital display and see what my wort was actually at instead of opening my fermenter to measure and risk contamination. Maybe I'm just being too anal about it.

I have heard that the probe thermometers may not be accurate. I'm assuming you mean a thermometer with a wire. Have you ever thought of putting a probe thermometer, like Blickmans, through the side of the fermenter with a weldless connection

 

[dcarter]

Just sanitize it and run it through the bung hole and seal it with the stopper for your bubbler. I do the same thing with my temp controller to allow my fermenterator to cool to the temp of the wort.

 

[Stauffbier]

Put a hole in the bucket lid, apply a grommet, and insert the probe end of a cheap dial thermometer that has been sterilized in boiling water and dipped in sanitizer. Just make sure to get a small enough grommet to make a tight seal with the probe.

 

[pelipen]

I have been thinking about investing in a wire probe thermometer to get a more accurate reading of my temperatures during fermentation. My thinking is I would put a small hole in my fermenter lid (I use 6 gal plastic buckets) with a small stopper/bung in it and thread the wire/probe through that so that it sits in the wort. Just curious if there may be any issues/side effects of having it sitting in there for a couple weeks. Thoughts?

I have a stainless probe in the center of every batch. As long as it's sanitized, you won't have a problem. How many hundred square inches of bucket surface area do you contend with vs the tiny additional amount for a probe?

Yes it is neat to see and log temperatures. Do it. It's a hobby and your beer will be fine.

 

[mikerobrewer]

I have heard that the probe thermometers may not be accurate. I'm assuming you mean a thermometer with a wire. Have you ever thought of putting a probe thermometer, like Blickmans, through the side of the fermenter with a weldless connection

Yeah, I was thinking more a thermometer on a wire. Some have a longer (3-4") actual probe end on them, which is why I was kind of using the term interchangeably. I'm using plastic buckets to ferment in, so I'm not sure how well one of the Blichmann Brewmometers would work. Then again, maybe it would.

Yes it is neat to see and log temperatures. Do it. It's a hobby and your beer will be fine.

That's what I'm thinking. Thanks.

 

[Stauffbier]

Yeah, I was thinking more a thermometer on a wire. Some have a longer (3-4") actual probe end on them, which is why I was kind of using the term interchangeably. I'm using plastic buckets to ferment in, so I'm not sure how well one of the Blichmann Brewmometers would work. Then again, maybe it would..

My thoughts on a digital meat thermometer with a metal probe on the end of a wire are; where the probe slips over the wire, specifically where it meets with the wire, could be a great place for bacteria to hide. As long as it's only the probe part that is inside of the bucket I guess it would work. From my experience the probe is usually not that long, though.

Just my thoughts. YMMV

 

[pelipen]

My thoughts on a digital meat thermometer with a metal probe on the end of a wire are; where the probe slips over the wire, specifically where it meets with the wire, could be a great place for bacteria to hide. As long as it's only the probe part that is inside of the bucket I guess it would work. From my experience the probe is usually not that long, though.

Just my thoughts. YMMV

Yes, definitely don't use that type. Huge opportunity for contamination, and they are not well sealed. I killed one by dropping it in a water bath once.

 

[william_shakes_beer]

Just sanitize it and run it through the bung hole and seal it with the stopper for your bubbler. I do the same thing with my temp controller to allow my fermenterator to cool to the temp of the wort.

+1

I did this once to see how much different the liquid was VS the temp control sensor on the outside of the bucket. (i got about 3 degrees) of course, you realize there is a temp gradient across the fermenter. Sensors at different distances from the center and at different depths will give you different numbers. If you want a REAL sense, you should put 12 sensors in, spread them out and average them... wait wait it should be a weighted average, since the center is warmer, but ya see, the yeast flows up the interior center column, and down the outside.... aaack ....laminar flow..... fluid dynamics.... coefecient of friction....... never mind its 3 degrees. My head hurts. I need a beer

 

[mikerobrewer]

Point taken, and agreed. You could get really ridiculous about it if you wanted to. All I want is to get an idea of what my wort's temp is. I'll probably just do like dcarter suggested. Seems simple enough and will give me what I'm looking for.

 

[mikerobrewer]

Or how about something like this put through a drilled stopper? The hole would, of course, have to be a very snug fit for the thermometer to keep the seal.

 

[samdjenn]

Came across this today, I recently found that you can salvage those temp probes by submerging them in hot oil (frying temps). What happens is water gets into the bi-metallic part of the probe and throws off the readings. Frying it in oil boils the water and it steams out. I don't know how to re-seal the probe though.