Is this thermometer's probe food safe?

[badmajon]

Hi, I'm thinking of getting this, it looks like it'd be perfect- indoor temp will monitor my ferm chamber's temp (converted chest freezer) and I could drop the probe into the brew bucket.

http://www.amazon.com/Taylor-1522-Indoor-Outdoor-Thermometer/dp/B001H1LTME/ref=pd_sbs_hg_4

My only concern is the food safety of this probe, would it be okay to have sitting in my beer for three weeks or more?

 

[chromados]

Your link is bad, But if you want to measure the temperature of the wort from inside the carboy you will want to use a thermowell and not just drop the probe into the beer. For my fermentation chamber i just tape the probe to the side of the carboy and have great success with that method.

Chromados

 

[Gremlyn]

I wouldn't put any probe into my beer. You want to use thermowells.

 

[badmajon]

Huh... I have a brew bucket actually. How would a metal thermowell go into this (or a carboy for that matter)?

This is a pain, I need to be able to monitor the temp inside my bucket. I'd figure the HDPE plastic would be an insulator, and therefore not going to be accurate if I simply stick a probe to the side...

The real solution is a sankey fermentor with thermowell, but that's big $$$. Plus, a 15.5g sankey wouldn't be ideal for 5 gal batches.

 

[Catt22]

FWIW, I use a wireless indoor/outdoor thermometer with the transmitter inside the fermenter bucket. I simply put the transmitter inside a zip lock bag to isolate it from direct contact with the beer. I actually use two bags for added insurance. One inside the other. The bag floats on the surface of the fermenting beer. This method eliminates the need for a thermowell penetration. The transmitters are too large to fit into a carboy. When using carboys I just bungee the transmitter to the side and cover with some insulation. One nice side benefit is that the receiver has a minimum/maximum memory feature that lets you monitor the temp swings as well as the current temperature. You can often pick these thermometers up for as little as $10 on sale and they are surprisingly accurate. I use them in all of my fermentation chambers and also in my serving freezer. I put the transmitter in a one gallon plastic jug filled with water in the serving fridge instead of inside the keg. Once I did this with my serving fridge, I learned that the controller differential can be set fairly wide, yet the beer temperature swings very little. I also discovered that the beer temperature in the freezer is considerably lower than the controller set point. I currently have my freezer set point at 44*F with a 6 degree differential and the beer stabilizes at 38*F with a min/max swing of only about 1.5*F. This is with a fan running continuously in the freezer. I also have fans in all of my fermentation fridges and freezers to help maintain more uniform temps.

 

[badmajon]

Interesting. Thanks for the information I appreciate it!

This also brings up another question- lets say you do see the temp spike too high, like 75f for a ferm that should go no higher than 68f. Is there really anything you can do at this point? Turn down the ferm chamber temp?

I'd just think that by the time the external temp decrease affected the internal temp, it might be quite a few hours and it'd be too late.

 

[emjay]

This is a pain, I need to be able to monitor the temp inside my bucket. I'd figure the HDPE plastic would be an insulator, and therefore not going to be accurate if I simply stick a probe to the side...

It IS a bit of an insulator, but the r-value on such a thin piece of HDPE is so low, that it's a non-issue. The thermal mass of 5-gallons of beer is so large, that it's never going to come even close to outpacing the resulting change in temperature of the exterior of the fermentor. The temperature differential between the fermentor's exterior, and the beer that's directly in contact with the plastic surface on the interior, would be MUCH smaller than the resolution specs on any of our temp controllers would allow them to even measure, anyways.

What's important is simply insulating the probe from the outside air. The low thermal mass of the air as opposed to the beer, and, to a smaller degree, the (hopefully) higher r-value of the insulating material you use on the probe, makes all the difference as to how the beer temp is measured instead of the air temp.

 

[broadbill]

This is a pain, I need to be able to monitor the temp inside my bucket. I'd figure the HDPE plastic would be an insulator, and therefore not going to be accurate if I simply stick a probe to the side...

The HDPE plastic acting as an insulator isn't an issue. Taped to the side, it will read almost exactly the same temp as the beer inside it. Do your own experiment and see that this is the case, or trust that all of the other people out there who use this method with great results. This is the method I use and it works fine, FWIW.

Don't trust me? FWIW the "tape to the side" method is also recommended by Jamil and John Palmer in one of their podcasts about fermentation control. Take a listen.

I would recommend insulating it from the air surrounding the bucket. Tape the probe to the bucket, then cover with bubble wrap or a piece of styrofoam.

I wouldn't worry about the probe being food safe (it probably isn't but that is just a rating), I'd worry about it getting wet and malfunctioning/dying on you.

Hope this helps.

 

[Catt22]

This also brings up another question- lets say you do see the temp spike too high, like 75f for a ferm that should go no higher than 68f. Is there really anything you can do at this point? Turn down the ferm chamber temp?

I'd just think that by the time the external temp decrease affected the internal temp, it might be quite a few hours and it'd be too late.

IMO & IME you are generally right, but there are a number of variables affecting the beer such as:

1. Target temperature desired
2. The current temp of the fermenting wort
3. The yeast activity level
4. The cooling power of your chamber or whatever
5. Fan vs No Fan to circulate air in the chamber
6. The volume of the fermenter
7. The placement/location of the controller probe
8. and probably some other things

If you have a fermenting wort that is highly active, generating substantial heat and/or maybe going volcanic the ferment may well be all but over with by the time you can get it sufficiently cooled back down. Fermentation happens relatively fast at very warm temperatures. I've had beers more or less finish out in little more than 48 hours, but that was without any temperature control at all and the fermenter just sitting in a room that got too warm. It went volcanic and blew the lid off etc. That was long ago when I first began brewing. This is why I prefer to pitch the yeast into wort that is at the low end of it's suggested optimum temperature range and let it warm up slowly in a controlled manner. IMO, it's much better to have it under control right from the start rather than working to cool it down if too warm.

 

[badmajon]

Wow, some awesome replies here. I've actually come up with what I think is a solution-

1) take a piece of copper pipe, solder a cap on the end (non lead yadda yadda) so it's watertight.
2) Drill a hole in the lid of the brew bucket,
3) Stick in a rubber stopper, drill that to fit pipe.
4) Insert said capped copper pipe, open side up, into the wort.
5) Fill copper tube with water. Water will not come into physical contact with wort, but will be an excellent conductor of heat when used with the copper tube.
6) Insert probe into water inside tube, which should be exactly the same as the wort temp.

How does this sound? I know it seems like a big overkill, and maybe it is, but I'm having problems with off flavors and I think it is because I am setting my ferm chamber temp and just walking away, in the meantime the temp might be getting too high. I'm going for maximum accuracy in order to eliminate variables.

6) Drill hole in copper cap and install thermowell.

 

[thebigt85]

I think copper contact with tormenting wort is usually something to avoid. I can't remember exactly what happens, but there is the possibility of creating unwanted compounds in your beer. Just my two cents

 

[emjay]

I think copper contact with tormenting wort is usually something to avoid. I can't remember exactly what happens, but there is the possibility of creating unwanted compounds in your beer. Just my two cents

Yes, it's pretty well-accepted that copper shouldn't really be used once yeast is introduced. Though the only metal my beer ever touches is stainless steel.

Copper might be cheaper, but there's a reason why nobody makes copper thermowells. I strongly advise going stainless steel. But the poster seems to have the idea that he needs to do it because taping the probe to the side of the fermentor and insulating it is somehow inadequate, which is far from the truth. The method works absolutely fine - it produces temperature measurements accurately (assuming you calibrate it correctly) and precisely, and is used by thousands of expert homebrewers, including even the most well-respected of homebrewing gurus. It's a proven method, both in theory AND in practise, and anybody who simply dismisses it (out of a poor understanding of the physics involved, or whatever) is only putting themselves at a needless disadvantage, either financially or in terms of the quality of beer they make.

 

[Catt22]

Wow, some awesome replies here. I've actually come up with what I think is a solution-

1) take a piece of copper pipe, solder a cap on the end (non lead yadda yadda) so it's watertight.
2) Drill a hole in the lid of the brew bucket,
3) Stick in a rubber stopper, drill that to fit pipe.
4) Insert said capped copper pipe, open side up, into the wort.
5) Fill copper tube with water. Water will not come into physical contact with wort, but will be an excellent conductor of heat when used with the copper tube.
6) Insert probe into water inside tube, which should be exactly the same as the wort temp.

How does this sound? I know it seems like a big overkill, and maybe it is, but I'm having problems with off flavors and I think it is because I am setting my ferm chamber temp and just walking away, in the meantime the temp might be getting too high. I'm going for maximum accuracy in order to eliminate variables.

6) Drill hole in copper cap and install thermowell.

Essentially that will work just fine. I use a similar thermowell with temp probe in my MT. It's just a 1/2" rigid copper pipe capped at one end. IMO, you need not bother filling the tube with water. I just position the probe so it touches the bottom copper cap. You could use a thermo grease or water as you suggest, but nothing at all in the tube works quite well. The air in that tube will be very near the same as the external wort temp and there will be very little air circulation inside the dead end tube. The response time may even be better than if it was filled some type of liquid if the probe touches the copper. I realize that the copper to probe contact can be iffy, but IME it's not a big deal in this application. It's much less of a hassle with the tube empty and the difference in performance, particularly when used in a fermenter will be negligible.

 

[samc]

I've done the probe in the fermenter as well as the probe insulated on the side of the fermenter and have found that once the temps settled into my fermenting range it didn't make a bit of difference on which method I used. I define bit of difference as less than 1 degree. As far as a probe in the wort, if it is stainless and you have the wired end properly sealed (silicone tubing for me) then it is not an issue to have it in the wort.

 

[badmajon]

Yes, it's pretty well-accepted that copper shouldn't really be used once yeast is introduced. Though the only metal my beer ever touches is stainless steel.

Copper might be cheaper, but there's a reason why nobody makes copper thermowells. I strongly advise going stainless steel. But the poster seems to have the idea that he needs to do it because taping the probe to the side of the fermentor and insulating it is somehow inadequate, which is far from the truth. The method works absolutely fine - it produces temperature measurements accurately (assuming you calibrate it correctly) and precisely, and is used by thousands of expert homebrewers, including even the most well-respected of homebrewing gurus. It's a proven method, both in theory AND in practise, and anybody who simply dismisses it (out of a poor understanding of the physics involved, or whatever) is only putting themselves at a needless disadvantage, either financially or in terms of the quality of beer they make.

Thanks I didn't know copper and yeast don't get along. I'll try the probe stuck to the side method, insulated in a bit of styrofoam.

Eventually, I'll get to my stainless thermowell method and we'll see if there is a difference.

 

[broadbill]

So I just reread your post...you said your fermentation chamber is a converted chest freezer. How are you controlling that? Since you said its "converted", it sounds like you did some sort of bypass/modification of its thermostat to bring it to fermentation temps.

 

[badmajon]

I used the ebay temperature controller. I have 2 of them, great little things they are.

 

[broadbill]

I used the ebay temperature controller. I have 2 of them, great little things they are.

So why don't you tape the ebay controller probe to the side of the fermenter and let the controller do the work of keeping the fermenter at a certain temperature?????

 

[badmajon]

I think the reason why most people don't do that is b/c it (the keezer/ferm chamber) can't effectively keep up with the wort temp.

If you had, hypothetically, a stainless steel coil installed in a sankey fermenter with glycol being pumped through it out of a small freezer which had been drilled and modified for such purpose, and THAT was hooked up to the temperature controller, I could see there being a point to it.

Ah brewing, its a gadget addiction.

 

[broadbill]

I think the reason why most people don't do that is b/c it (the keezer/ferm chamber) can't effectively keep up with the wort temp.

Yeah, I've never had that problem. Also, I can't imagine you could keep up manually adjusting the temperature, unless you baby-sat it for the first 48 hours or so...

 

[emjay]

My chest freezer keeps up just fine as well. The yeast can warm up the beer significantly, but it's really not even close to being able to outpace a freezer.

Also, I think that saying "most people don't do that" is totally erroneous.

 

[Gremlyn]

If you're going to make a thermowell with a stopper... might as well just buy one:
http://morebeer.com/view_product/16672/beerwinecoffee/Stopper_Thermowell