Grilling meat without a thermometer is like transplanting corneas while blindfolded: There’s a good chance things will end badly. Hot dogs are hard to ruin, but when you’re tackling a big and expensive cut of meat, accurate readings matter.
In the cooker
Don’t trust the thermometer on your grill or smoker lid. Those gauges are notoriously inaccurate. For one, they’re not even near the meat. No surprise that readings can be up to 40°C out of whack.
Good: A $5 to $10 oven thermometer sitting on the grate is the same type of thermometer as the one on the lid, but at least it’s in the right place.
Better: A $20 to $30 digital oven thermometer with a thermistor probe goes inside the cooker, with a wire connecting it to an external readout.
In the meat
To check doneness, you need to know the temperature within the meat.
Good: It’s basic and costs less than $10, but a bi-metal instant read dial thermometer is also slow (up to 30 seconds) and not very accurate. Then again, at least it’s not one of those forks that says “done” when you poke the roast.
Better: Faster and more reliable is a digital pocket thermometer or a leave-in the meat remote wire thermometer ($15 to $30) with a thermistor.
Best: Top-of-the-line thermometers ($100 and up) use a thermocouple probe, which is super-fast, hair-splittingly accurate, and tiny (for precise readings right at the tip).