So I was wondering how you all take your mash temperature. Where do you put the probe to get your measurement? I get different readings depending on where it is. Obviously hotter up top and cooler near the bottom. Just trying to get a consensus. Gracias and Cheers!
Mash Temp Measurment
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I stir until the temperature is the same throughout. If the temperature is different, I stir some more. Once it's all equalized, I cover it and walk away. It doesn't vary after that.
Ill probably get killed for this, but Ive about given up on trying to measure mash temp. I depend on getting my strike temperature right. Experience tells me where I need to be.
The mash is pretty chunky and the sweet spot on the probe is pretty small. Stir it as well as you can and sample in different places. You should see a trend and you can kinda average it in your mind.
I have noticed better results with a (gasp) analog thermometer, it seems to have a bigger sweet spot. I used a cheap ($8) 12" lab thermometer from the LHBS. I have recently upgraded to an NIST traceable high dollar ($12) thermometer.
Yooper probably has a Blichmann on her pot. It is good to be the queen.
The mash is pretty chunky and the sweet spot on the probe is pretty small. Stir it as well as you can and sample in different places. You should see a trend and you can kinda average it in your mind.
I have noticed better results with a (gasp) analog thermometer, it seems to have a bigger sweet spot. I used a cheap ($8) 12" lab thermometer from the LHBS. I have recently upgraded to an NIST traceable high dollar ($12) thermometer.
Yooper probably has a Blichmann on her pot. It is good to be the queen.
BrewingGunner
Well-Known Member
I use a keggle and notice variation and temp drop as well. I've fixed this by adding a RIMS tube to my rig, I just got it from Bobby at brewhardware. On a test run my temp at the output of the RIMS is within 1/2 of a degree of the mash tun. I believe the constant recirculation, adding heat as necessary, keeps the temp solid. A pump and RIMS tube is definitely worth the $.
Heck, no! I don't have any Blichmann gear at all. Oh, except for a free hat he gave me at NHC.
Well, he didn't even give it to me. It was tossed into a crowd, and since I'm bigger than John Maier (who I was standing next to, talking) I caught it. But it does have the Blingman logo. I do have a nice thermometer, a Thermapen, that I've had for about 6 years. I open it, check the temperature in about 5-6 places and when it's the same (or within .5 degree), I'm done stirring.
For initial dough in I measure a couple spots, when they all more or less agree I know I've stirred enough and put the lid back on. After that my RIMs monitors the temp on it's outflow, which corresponds pretty well to what I see on the kettle thermometer.
Well Yooper, you have a cool hat and a pretty good thermometer. Your sensor has a bigger effective area, what Im calling sweet spot than the cheaper digitals. http://www.thermoworks.com/products/thermapen/thermapen_sensor.html
Well,I use my 5 gallon SS stock pot for partial mash/partial boil biab. I add the grains to the mash water when the floating thermometer lashed to the kettle handle reads 150F. I stir the grains till I break up all the doughballs & evenly wet them. When the temp reads 152F generally,I clap the lid on & wrap it up in my winter hunting coat for the 1 hour mash. The floating thermometer stays in,but has to be pushed downa little to get the lid seated.
So it's floating at an angle through the center of the mash. I wind up gaining 1 degree from the trapped steam in the kettles' dead space.
So it's floating at an angle through the center of the mash. I wind up gaining 1 degree from the trapped steam in the kettles' dead space.
BigRedHopHead
Well-Known Member
+1 on the thermapen, I use it for everything temp related. I have a big SS mash paddle which tears through the mash and mixes really well. I believe this helps to distribute temp more evenly. My thermapen is rarely more than .3-.5 degrees off in several places.
The infrared laser pen thing I bought has about the same accuracy so far. Gunna experiment with it further against readings from the floating thermometer. The clip on dial thermometer I got is so easy to knock out of adjustment & doesn't adjust itself to start temp of sparge water,for example,that it seems to me a waste of money. No dang better than quick check thermometers I go through left & right. The laser & floater are the clear winners thus far...
dyqik
Well-Known Member
The infrared laser pen thing I bought has about the same accuracy so far. Gunna experiment with it further against readings from the floating thermometer. The clip on dial thermometer I got is so easy to knock out of adjustment & doesn't adjust itself to start temp of sparge water,for example,that it seems to me a waste of money. No dang better than quick check thermometers I go through left & right. The laser & floater are the clear winners thus far...
IR thermometers only work on sufficiently black surfaces (i.e. with high and uniform emissivity in the IR), and only measure surface temperatures. They're great for most painted surfaces and dirty engine blocks or bearing housings, but they don't work accurately through glass or water, or on reflective surfaces (e.g. water on the top of the mash - the reflection from the surface will mix the temperature of the mash with the temperature of the background). You may see some weird effects using one for bulk liquid measurements, but you might get away with it.
A high quality 12" probe clip-on thermometer that's been calibrated is the best bet for getting a stable and representative measurement. If yours is easy to knock out of adjustment, then there's a serious issue with its calibration adjustor.
Nope. Not according to the description of the IR pen;http://www.midwestsupplies.com/alltemptm-digital-wine-food-thermometer-with-clip.html
And that dial one is just like any other dial type;guaranteed to be a pain in the butt to keep adjusted & get a good reading. I've tried. It worked the firsttime. But bump the dial,& you're fooked.
And that dial one is just like any other dial type;guaranteed to be a pain in the butt to keep adjusted & get a good reading. I've tried. It worked the firsttime. But bump the dial,& you're fooked.
http://www.thermoworks.com/emissivity_table.html
As you can see in this chart, the emissivity of water is .95, glass is .92. You dont measure through water or glass, you are indeed measuring the surface temperature.
In my experience, the most serious limitation of IR thermometers for cooking is with simmering liquids. The water vapor clouds the surface and the reading goes all over the place.
That, and it doesnt work with stainless steel. I can however measure the temperature of the water in a stainless pan, as long as it isnt too hot, I just cant measure the temperature of the pan directly.
As you can see in this chart, the emissivity of water is .95, glass is .92. You dont measure through water or glass, you are indeed measuring the surface temperature.
In my experience, the most serious limitation of IR thermometers for cooking is with simmering liquids. The water vapor clouds the surface and the reading goes all over the place.
That, and it doesnt work with stainless steel. I can however measure the temperature of the water in a stainless pan, as long as it isnt too hot, I just cant measure the temperature of the pan directly.
Looks like I'll just have to do it all again & report back. Failing this,I'll just stick to floating thermometers. That thermopen requires sticking your hand in a steaming hot kettle to take measurements with what looks like a 3" probe.
MisterGreen
Well-Known Member
Heck, no! I don't have any Blichmann gear at all. Oh, except for a free hat he gave me at NHC.
I do have a nice thermometer, a Thermapen, that I've had for about 6 years. I open it, check the temperature in about 5-6 places and when it's the same (or within .5 degree), I'm done stirring.
+1 on the Thermapen.
I tend to think as mash temps as more an approximation than an absolute number. For instance 152..ish. I would be happy with anything between 150-154. If it gets above or below that range than I either heat or cool the mash. Even when I nail my mash temp I notice temperature variability in different parts of the keggle.
I would be happy with anything between 150-154. If it gets above or below that range than I either heat or cool the mash. Even when I nail my mash temp I notice temperature variability in different parts of the keggle.
dyqik
Well-Known Member
That brief description (from someone selling them for measuring liquid temperature) doesn't say whether it measures the surface or bulk temperatures. They are different, and IR thermometers can not measure the temperatures inside the bulk of the liquid, as water is opaque to them (I design far-IR telescopes and instrumentation for a living - I have know the IR radiation properties of a lot of materials). The attenuation constant of water in the mid-IR is between 50,000 and 200,000 1/meters, which means that 63% of your signal is coming from the first 10 microns of liquid, and 99.9% of the signal from the top 40 microns (~0.2 mil).
Dial thermometers shouldn't change calibration when bumped - none of my three do. They all need a wrench applied to them to change the calibration.
