[Wort-H.O.G.]

So I have to ask who has submersible thermometer they can substantiate maintains an accurate temp?

Mash temp and water temps are so critical...what can you trust and how do you verify it periodically ?

I've used 3 different thermometers and get 3 different readings...2 are about 1.5 degree apart and the other is 4'degrees higher.

[tygo]

It's not submersible but I use a thermapen and highly recommend it.  It's pricey but you can use it for cooking, BBQing, and brewing.  Wouldn't leave home without it!

[Jimmy K]

If you really want to be sure, buy a digital thermometer that you can calibrate and get a lab certified glass thermometer to calibrate it with.  I don't do that though. I use this..
http://www.amazon.com/Taylor-Professional-9306-Thermocouple-Thermometer/dp/B000XS7WTG/ref=sr_1_9?s=home-garden&ie=UTF8&qid=1360901097&sr=1-9&keywords=taylor+instant+read+thermometer
It and the Thermapen are splash proof, but not waterproof.

[oly]

At work we have a NIST-traceable calibration block that is used to cal all the thermometers used at work, so I can check mine in that block.

But that's a pain  so I just got one of these:

http://www.thomassci.com/Instruments/Digital-Thermometers/_/Thomas-Traceable-Lollipop-ShockWaterproof-Thermometer/

$30 for a waterproof nist-accurate 10" probe lolipop thermometer. works great.

[amh0001]

I read one of these threads a while back, EVERYONE recommended Thermapen. So I got one....Done deal! Never looked back.

PS i got the pink one

[Wort-H.O.G.]

I have some of the devices mentioned, but the issue is they all are different. That begs the question, which is correct?

I guess I will have to run a controlled test- melted ice in a glass to create freezing temp of 32f, and boiling water at 210f at my elevation, then compare each devices readings in the freezing and boiling points.

[tygo]

I guess I will have to run a controlled test- melted ice in a glass to create freezing temp of 32f, and boiling water at 210f at my elevation, then compare each devices readings in the freezing and boiling points.

You should also check what they're all reading at 150 or so.

[Wort-H.O.G.]

"You should also check what they're all reading at 150 or so."

Can't really replicate 150f. That's why you measure 32 and boiling point temps as a calibration measurement.

[AmandaK]

I use the ThermoWorks RT600C: http://www.thermoworks.com/products/low_cost/rt600c.html

Works VERY fast (3-4 seconds) and costs 25% of the Thermapen. Mine is accurate within 1.2*.

[HoosierBrew]

FWIW I have the previously posted $30 lollipop NIST-traced thermometer, alongside a bimetal. I feel that my temp acccuracy has improved dramatically.  Used the lollipop for the 1st time on my current batch on tap (an APA) , mashed @ 152, and I love the beer . I think the accuracy is there. $30 very well spent.

[Hokerer]

"You should also check what they're all reading at 150 or so."

Can't really replicate 150f. That's why you measure 32 and boiling point temps as a calibration measurement.

Except that you don't care whether your thermo is accurate at freezing or boiling.  The mash temp range is what you care about, hence calibrating it around 150.  Just because your thermo is accurate at freezing and/or boiling (real fun getting both ), means nothing about it's accuracy around mash temps.

[Wort-H.O.G.]

Disagree on your analysis of freezing and boiling for calibration. It's a well accepted way to calibrate thermometers , considering most do not havens calibration block. The point being, you don't care about the temps of 32 and 210-212, they just provide references on both ends of temperature spectrum so you can establish a calibration curve for your thermometer.

How would you replicate 150f or similar mash temp and know its that temp without a calibration block??

[BrewQwest]

I guess I will have to run a controlled test- melted ice in a glass to create freezing temp of 32f, and boiling water at 210f at my elevation, then compare each devices readings in the freezing and boiling points.

You should also check what they're all reading at 150 or so.

+1 to the 150F... we don't mash at freezing (is the slush supposed to be 32 or is the frozen water supposed to be 32 or is 32 somewhere within a degree or two different) and we don't mash at boiling (is 210 actually boiling at your elevation utilizing your brewing gear or is it a degree or two different)? And with only one thermometer, how do you verify its accuracy when you do get to mash temps?
I now standardize on an RTD probe (+/- 1%) hooked to a PID previously calibrated with a lab thermometer. Prior to this I ran a digital thermometer, stem thermometer, and a submersible thermometer at mash temps while heating up some water.. Make up a chart of any differences in any of the readings at any temp between them... cheers!!

[fmader]

At work we have a NIST-traceable calibration block that is used to cal all the thermometers used at work, so I can check mine in that block.

But that's a pain  so I just got one of these:

http://www.thomassci.com/Instruments/Digital-Thermometers/_/Thomas-Traceable-Lollipop-ShockWaterproof-Thermometer/

$30 for a waterproof nist-accurate 10" probe lolipop thermometer. works great.

+1

[denny]

At work we have a NIST-traceable calibration block that is used to cal all the thermometers used at work, so I can check mine in that block.

But that's a pain  so I just got one of these:

http://www.thomassci.com/Instruments/Digital-Thermometers/_/Thomas-Traceable-Lollipop-ShockWaterproof-Thermometer/

$30 for a waterproof nist-accurate 10" probe lolipop thermometer. works great.

+1

+2