Importance of Thermometor Calibration

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Reverend JC

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When i first started AG brewing i would use a glass candy Thremometor for the strike, rest, and sparge water and a meat Thermometor for the mash. I would always get a really high strike, always miss my target termp and have to add cold water to get it to the proper temp.

Then i started just using the meat Thermometor and without even thinking about it i began hitting my temps and I thought, man i have this down!!!

At that point i started missing my normal Eff. of 75-82% range. I started getting into the 60 to 65% range. And i would always get my beers down to 1.010 or 1.09 and i would think, wow, uh, this is supposed to have some residual sweetness. oh well, goes down good.


My Eff. was suffering because my sparge temp was always around 164 and not hot enough to really loosen up those sugars and help get them into the wort. The beer was always dry because my supposed 152 temp was always around 146.

For eveyone who has not calibrated your thermometors i suggest you do so, it is the easiest thing to ensure a constant factor to rely on in the brewing process. None of my beers were bad, they just were not as good as they could have been.
 

Uncle Argyle

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I am having an issue getting my mash and sparge temps right and I want to invest in a decent thermometer. I am also currently using a candy thermometer and a turkey fryer thermometer for the mash. both of which you can't calibrate really...just adjust to boiling water.

what do you use for a thermometer or what would you recommend? (I use a 5 Gal cooler MLT...if that changes a recommendation).

Thanks,

Uncle Argyle
 
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Reverend JC

Reverend JC

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They make bewing thermometors that are inexpensive and will do the trick but those too need calibrated when purchased.
 

Joker

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Is there a debate between digital and analog thermometers? Anyone have strong feelings one way or the other. Currently I use an analog but have been thinking about going digital but not sure if its worth it or not.
 

Drunkensatyr

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I use both. I calibrate the analog to ice water and to boiling water. Then I check the analog against the digital. I never rely on only one thermometer.
 

toddq

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I finally figured out the other day I've been having the same problem, but in the other direction. My last two batches have refused to ferment lower than 1.028, and after checking my thermometer, it appears I've been unintentionally mashing in the 162-167 degree range, leaving lots of unfermentable sugars. After getting rid of this one, I will be joining the two thermometer club. The odd thing is, it used to be reasonably accurate, and now it's waaaaay off.
 

Surly

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I have very, very little experience with thermometers.....Yet,....

I do know the importance of accuracy in brewing. I have one analog thermometer with about a 6 inch probe. I would like to pick up a cheap digital to check my mash tun temps with.

Can digital thermometers be calibrated to ice water & boiling water?

Any suggestions on a cheap digital?
 

derogg

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VWR or Control Compay have a good water proof digital thermo. You can get a lollipop style or a remote probe. Both are certified and traceable. I think they have two different grade of accuracy. I have a lollipop style, got it for about $28.00 shipped. Good customer service. I busted the battery cover, sent an e-mail, and had a new cover sent in a week, no charge. - Dirk
 

david_42

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I calibrate to boiling ethanol (actually 80 proof). 172F (78C) is the perfect calibration point for home brewing.
 

Chriso

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Bobby_M said:
Target has a yellow one on their website that is waterproof and calabratable for only $15. I bought two.
Wal-mart also has a similar for $15 - removable probe, silicone wire, can be submerged in either wort or sanitizer, shows max and min temp, and has a temp alarm.
Mine looks just like this:
 

IowaStateFan

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chriso said:
Wal-mart also has a similar for $15 - removable probe, silicone wire, can be submerged in either wort or sanitizer, shows max and min temp, and has a temp alarm.
Mine looks just like this:
I just bought that one but haven't had a chance to use it. What are your experiences with it? Is it pretty accurate? Is it really waterproof?

Thanks
 

tbulger

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The yellow traceable thermometers have issues too. Mine broke down after a month or so. Threw the receipt away the day before too. Sent it back and cost just about as much to recalibrate as the damn thing cost.
 

Bobby_M

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That's why I'm sticking with the home-calibration cheapies... and using two for redundant verification. If they read differently, I don' t know which is right but I will know that one of them is.
 

Chriso

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IowaStateFan said:
I just bought that one but haven't had a chance to use it. What are your experiences with it? Is it pretty accurate? Is it really waterproof?
Yep on both accounts. There are lots of warnings in the archives about silicone probes on which the cord itself isn't waterproof. This is NOT the case with this unit. I can dunk the probe and the entire length of the cord into my boiling wort, repeatedly (and have done so), and it measures "correctly" (I assume it's correctly) every time. ... Apparently there are both sealed and unsealed silicone probes. Whoda' thunk it.

As far as HOW accurate it TRULY is, I don't know. I have a digital stick-style ( http://www.walmart.com/catalog/product.do?product_id=7894642 ) also from walmart, and it always agrees with the probe thermometer within 1 degree F.

I can stick a couple of glass thermometers and a metal dial thermometer in the mash, along with my two digitals. The two digitals always agree, the three analog thermometers are almost always scattered "all over the charts".
 

Didymus

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Hmm, educational thread.. one more thing to worry about :cross:
 

DaBearSox

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I had the same problem...well I could tell with my last batch this must have been it...my refridge themo says its 68 degrees in the air and the digi says 75...I want to brew tonight so I went out and got a cheapo stick themo from Rite Aid so I can have a few different readings. I will get a nicer tracable themo when i can get to somewhere that sells them, but brewing tonight was a priority. I am going to try to calibrate with boiling water (i think my boiling temp here in denver will be around 202 b/c of the alt) just to see if it is on target....

maybe this APA won't finish at 1.007-1.008
 

beerkrump

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Beware of the probes on some of the cheaper digital thermometers. They are not water proof around the junction between the probe and the wire. I had one that worked great twice and the was off 30° to 50° depending upon the range being read the third time I used it. I've got a decent analog stick thermometer that can be calibrated and a candy thermometer my wife uses, now. I'm thinking about picking up an NIST alcohol scientific thermometer to use as a reference to calibrate and a quick read digital stick that can be calibrated.
 

Yankeehillbrewer

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IMO, The best practice is to use 1 Thermometer in your brewing process, that way your reference point is always the same. I personally prefer the floater and just calibrate it every now and then.
 

jpc

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IMO, The best practice is to use 1 Thermometer in your brewing process, that way your reference point is always the same. I personally prefer the floater and just calibrate it every now and then.
Agreed. As they say, "The man with one watch always knows what time it is. The man with two is never quite sure."
 
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