Checking One's Oven For Proper Temperature Calibration
Several times over the past week I have read mentions on various threads regarding checking one's oven to see if it is actually baking at the temperature that is set on the dial, or the digital pad, of the oven's thermostat..Thermometers that hang semi-permanantly in the oven are OK for this purpose, although I have never found them particularly easy to read..And, as has been mentioned, thermometers kept constantly exposed to heat wear out, thus becoming less accurate as they age..
A far better option, albeit a much more expensive one than hanging oven thermometers, is to use a oven test thermometer designed to check more accurately the operating temperature of an oven..There are two basic versions of these oven test thermometers..There is the old-fashioned analogue mercury-filled glass tube thermometer, and the more modern digital versions that have a wire-mesh covered flexible probe that extends into the oven attached to a digital readout that resides outside of the oven..
When I attended culinary school I was given as a gift that first year an analogue version of the test thermometer..It is the Taylor Instruments 5903 Professional Fold-Up Oven Test Thermometer, and I can highly recommend it for its accuracy..It told me that my home oven bakes about 20F-25F hot; and that over the years that virtually every commercial oven that I have used is innaccurate..Commercial convection ovens I have especially found to be inaccurate, as well as having many hot and cold spots..Some of my comments over the past several weeks on various threads regarding convection ovens reflect my knowledge of them by virtue of having tested several dozen of them over the years..
Anyone that is interested in accurate, repeatable results in their baking I urge to have their oven tested..Just as the speedometers and odometers on motor vehicles are seldom as accurate as most people assume that they are; so too do ovens rarely bake accurately at the temperatures that people set them at..