It’s a question that has plagued Thanksgiving cooks for generations: When is your turkey perfectly done?  Getting the right answer is key—undercook that bird and you risk making your guests sick with food poisoning; overcook it and the white meat is tough and dry—although safe to eat.

For decades, one purported solution to this holiday hassle has been the pop-up timer that comes with some birds, a device invented to take the uncertainty out of poultry cooking times, especially for Thanksgiving turkeys.

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Testing Pop-up Timers

But are these timers safe and reliable? To find out, we tested 21 pop-up thermometers in whole turkeys and turkey breasts. Our testing covered pop-up timers bought online and put into place by cooks before sliding the bird into the oven, and models pre-inserted in the meat at the processing plant. To determine the pop-ups’ accuracy, we also measured the internal temperature of the meat with a calibrated reference thermometer. Our findings may make a few eyebrows pop:

Self-inserted and manufacturer-inserted timers generally “popped” in our tests at internal temperatures above 165° F—the minimum safe temperature for all poultry. But three timers popped up when meat was still below that safe zone, one as low as 139.5° F.

The low readings are a concern. Cooking poultry to 165° F helps ensure that potentially harmful bacteria that can cause food poisoning—such as campylobacter and salmonella—are destroyed. Serving undercooked turkey means you risk sending your guests home with a nasty case of food poisoning.

Our food safety experts recommend that cooks not rely on these timers to tell whether their holiday bird is done. Instead, use a conventional meat thermometer to check the internal temperature in the thickest part of the breast and in the thigh between the drumstick and the body, and take several readings.

The Best Meat Thermometers

In a separate round of testing, our experts assessed instant-read and leave-in analog and digital meat thermometers for temperature accuracy, repeatability, response time, and product features.

Based on this testing our experts recommend that home cooks purchase a digital meat thermometer. (They make nice stocking stuffers, too.) Overall, compared with analog models, instant-read and leave-in digitals are more accurate, are easier to read, and have faster response times. Testing found that analog thermometers are also not suitable for use in thinner cuts of meat such as most steaks and boneless chicken breasts.

Among instant-read thermometers we tested, the CDN ProAccurate TCT572 was the top model. Accurate and consistent, it also features a foldaway probe. But at $80, it’s also one of the most expensive recommended instant-read digitals. Another highly rated model, the Polder Stable Read THM-379, performed almost as well as the CDN yet costs just $18. 

Leave-in digitals that remain in the meat while it cooks offer more features—such as audible alerts and the ability to transmit temperature readings to a wireless unit or smartphone—but generally cost more than instant-reads. Williams-Sonoma’s Smart Thermometer 87072 was the top-rated model of all those tested; at $200 it was also the most expensive. When connected to WiFi and paired with a free app, the Smart Thermometer sends temperature readings and other alerts to any Apple mobile device. Two less costly leave-in wireless models are Oregon Scientific’s Wireless BBQ/Oven AW131, $40, and iGrill’s mini Bluetooth, $40. The Oregon Scientific doesn’t offer as many features as the Williams-Sonoma thermometer but performed very well in our testing.