There are times when experienced cooks need to rely on more than just touch, smell and sight for success. An instant-read thermometer eliminates guesswork in cooking. Beyond checking a roast for doneness, a good thermometer can help you find the right temperature for proofing yeast or tempering chocolate, and it can tell you whether your burgers are medium or well done. Toni Lydecker surveys the available types of thermometers, from pocket dial instant-reads and pocket digital thermometers, to the digital thermometer with probe that can remain in food as it cooks, to the high-end thermocouple thermometer. She assesses the strengths and limitations of each type, and also includes information on how to use instant-read thermometers, and where to buy them.