cooling wort - helps if you have a working thermometer

[jboehle]

My brew last night was going reasonably well until it was time to cool the wort. Put it in a sink of ice water, quickly went through about 10 lbs of ice, temp was coming down nicely, thermometer said 94 F or so, but it stopped and just hung out there. Hmmmm. I was so concerned about the temp I forgot to stir it every 15 min or so. About 45 min in, I stir it, the temp jumps back up to 120 F! Argh! Figured there musta still be a column of hot liquid in the center or something, but didn't make a whole lot of sense. Let it go another 20 min or so, temp is only 112!? One side of my sink will just overflow to the other side, so I just start running cold water all the time, giving it a good stir every so often, temp won't come down. Not making any sense! So I go get the thermometer that came with my turkey fryer, it says 74 F. Doh! Guess I should always use 2 thermometers. Apparently boiling the probe of my $15 digital thermometer from Target killed it. Time for an equipment upgrade, I say!

[BourbonDrinker]

I actually use an analog thermometer from a turkey fryer when I brew. My stockpot lid has a small hole just large enough to put the thermometer in. I leave it in for the boil, and the cooling so I always know how hot it is.

[jboehle]

I calibrated my turkey fryer thermometer in boiling water and it said 200 F instead of 211-212. I don't know if it's off by that much throughout the whole scale, or if it's progressively worse, etc., so I'm looking for something more accurate.

[klickcue]

I calibrated my turkey fryer thermometer in boiling water and it said 200 F instead of 211-212. I don't know if it's off by that much throughout the whole scale, or if it's progressively worse, etc., so I'm looking for something more accurate.

You could check the ice point of your thermometer which is ice with just the smallest amount of water added. You will need a container as deep as the probe length. This will give you 32oF. The boiling point in Lawrence is about 211oF. Water boils at a little over 212oF at sea level. If your dial thermometer is off at the ice point, there is a hex nut on the back of the dial, hold the hex nut and turn the face to line up with the ice point. Then you can check the boiling point for your elevation.

Some of the best dial thermometer are manufactured by Taylor.

On a good glass thermometer, there will be depth mark to show how deep to expose the glass.

The quickest was to kill a digital probe on a shielded wire is to sink the probe into water to were it get to the shield. Some shield probes are made to be dunked and others will let liquid into the probe and short out the thermistor giving false readings. Just dry the probe out in the oven and it should be good to go again.

A digital thermometer with the electronics attached to the temperature probe are just for spot checks and not made for long term elevated temperature.

[Blktre]

The best calibrating thermo is a lab grade. Alcohol base lab theromos are fairly cheap. There are a few different types to be aware of.

Partial immersion - Have a line showing the immersion depth

Total immersion - Thermometer is immersed so that the depth is approximately equal with the temp on the thermometer's scale

Full immersion - The entire thermometer is immersed, usually used in a site tube on equipment

Here is also an excellent thread that talks about calibration. But you can get as crazy as you want with it. So just use it as a guideline.

http://www.brews-bros.com/index.php?showtopic=3734&st=0