Although some experienced cooks rely solely on sight when gauging whether meat is cooked, a meat thermometer ensures a safe internal cooking temperature, as recommended by the United States Department of Agriculture (USDA).
One of the best sources for meat thermometer reviews is ConsumerReports.org, which published a comprehensive review of 11 models in late 2008. Another excellent source, Cook's Illustrated magazine, has published three separate reviews of meat thermometers. As a group, editors find leave-in thermometers are more prone to defects than instant-read thermometers. Good Housekeeping magazine has two separate reviews covering a large number of models; in one review, editors test 22 models of leave-in and instant-read thermometers, judging speed as well as how easy they are to insert and see the readout.
In addition, we consulted less comprehensive meat thermometer reviews at other publications, some of which only discuss a single model. Most recent is a 2009 review by Joe Yonan at The Washington Post, in which he names favorite kitchen items for holiday gifts, including one thermometer. ConsumerGuide.com rates one model of leave-in thermometer on value, performance and features in a 2007 post. Meanwhile, a 2004 review in Bon Appetit magazine recommends four instant-read and leave-in thermometers, and an article at Food & Wine magazine from the same year recommends two thermometers. It's not clear whether the models were tested.
We read reviews at retail websites like Amazon.com and Cooking.com, where owners can rate their meat thermometers and post opinions. Generally, we found meat thermometers receive lower average ratings than many other kitchen items.
There are two kinds of meat thermometers: oven-safe (also known as leave-in) and instant-read. The probe of a leave-in thermometer is inserted into the meat before cooking and left there, while the digital monitor remains outside the oven or grill. That makes leave-in meat probes best for cooking large cuts like roasts or whole poultry. You can continually monitor a single piece of meat without opening the oven or grill, allowing heat to escape. One criticism, however, is that certain parts of the meat cook faster than others and incorrect placement of the probe could result in overcooked or undercooked meat.
The probe of an instant-read thermometer, on the other hand, is inserted into the meat periodically while cooking to check whether it's done or not. Instant-read thermometers usually cannot be left in the oven or grill without becoming damaged from the heat. That makes them better for spot-checking food. Instant-read thermometers are more versatile than most meat probes since you can easily use them to check smaller items, such as cut-up chicken, steaks, or fish. They can also be used to check liquid temperatures, though most aren't true replacements for a candy thermometer or deep-fry thermometer. Some models do have a pot clip, however.
After reading professional and owner-written reviews, we discovered that the probes on many meat thermometers are not particularly durable, especially when cooking with high heat on a grill. Some probes never work, and some stop working after only a few uses. It's clear from reading owner reviews that some of the durability problems are due to misuse, such as leaving an instant-read thermometer in a closed oven or grill. In other cases, the probe simply stops working with no apparent cause. For this reason, consumers may want to test a new thermometer's accuracy in boiling water before cooking an expensive cut of meat. Some cooks argue that it's better to buy cheap a meat thermometer (since durability seems iffy in general), or select a more expensive model that sells replacement probes at a lower cost than replacing the whole thermometer.
Another observation: Some meat thermometer models are sold under more than one brand name. For example, the Polder Classic Cooking Thermometer/Timer (*Est. $20) is exactly the same as the ThermoWorks Original Cooking Thermometer/Timer (*Est. $25). Consumers should compare prices and choose the model that offers the best value and warranty.