seafra
01-21-2009, 08:57 PM
Stickie thermometers are surprisingly accurate for a $3 investment. Unfortunately, they do not necessarily measure what a brewer really needs to know. They are good at measuring ambient temperature when adhered to glass or plastic. These materials are great insulators---even more so for plastic, and atmospheric conditions (temperature and humidity) have greater effect on an external liquid crystal strip than the core temperature of the wort/beer.
I have two good brew buddies: one still ferments in buckets (despite the fact that he is a radiologist with plenty of disposable income); the other is a chemist that, like me, has a serious case of GAS (Gear Acquisition Syndrome). The chemist and I have stainless steel conical fermenters and chide our tight wad friend for making beer in a plastic piece of shite that his son brought home from McDonald's.
In one of our many attempts to get Ebenezer to upgrade his equipment, we showed him how he had no idea at what temperature he was fermenting. Using a digital lab thermometer with a 12 inch probe, we measured the core temperature of a batch of his beer in vigorous fermentation in the bucket. The beer was 8 degrees above the reading of his stickie thermometer; however, the stickie was only 2 degrees above ambient temperature.
So, this anecdote should have ended with Dr. Skin-flint ordering a shiny new Blichmann conical. To the contrary, he said, "D@MN! Now I've got to figure out how to keep my bucket 8 degrees cooler!" Even when our friend further explained that lowering the ambient temp 8 degrees would not conduct off the equivalent through plastic, he just said, "FINE! I'll make it 10 degrees cooler."
P.S. Stickies are much more accurate on stainless steel. At the time of the temperature test above, I was still fermenting in Corny kegs. My core temp measured 5 degrees above ambient and only 2 degrees above the stickie thermometer.
P.S.S. Although we did not measure a glass carboy, Mr. Wizard estimated that a carboy should measure about 4-5 degrees off from a stickie thermometer, as the insulating properties of glass are around half that of plastic.
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Sj (http://www.suzuki-tech.com/wiki/Suzuki_SJ)
I have two good brew buddies: one still ferments in buckets (despite the fact that he is a radiologist with plenty of disposable income); the other is a chemist that, like me, has a serious case of GAS (Gear Acquisition Syndrome). The chemist and I have stainless steel conical fermenters and chide our tight wad friend for making beer in a plastic piece of shite that his son brought home from McDonald's.
In one of our many attempts to get Ebenezer to upgrade his equipment, we showed him how he had no idea at what temperature he was fermenting. Using a digital lab thermometer with a 12 inch probe, we measured the core temperature of a batch of his beer in vigorous fermentation in the bucket. The beer was 8 degrees above the reading of his stickie thermometer; however, the stickie was only 2 degrees above ambient temperature.
So, this anecdote should have ended with Dr. Skin-flint ordering a shiny new Blichmann conical. To the contrary, he said, "D@MN! Now I've got to figure out how to keep my bucket 8 degrees cooler!" Even when our friend further explained that lowering the ambient temp 8 degrees would not conduct off the equivalent through plastic, he just said, "FINE! I'll make it 10 degrees cooler."
P.S. Stickies are much more accurate on stainless steel. At the time of the temperature test above, I was still fermenting in Corny kegs. My core temp measured 5 degrees above ambient and only 2 degrees above the stickie thermometer.
P.S.S. Although we did not measure a glass carboy, Mr. Wizard estimated that a carboy should measure about 4-5 degrees off from a stickie thermometer, as the insulating properties of glass are around half that of plastic.
________
Sj (http://www.suzuki-tech.com/wiki/Suzuki_SJ)