What Shall the Stem of a Meat Thermometer Be Constructed Of?

The FDA Food Code does not prescribe one universal metal. It prohibits glass sensors or stems unless the glass is enclosed in a shatterproof coating, so the device must be durable and not present a breakage hazard in normal use.

Only under the Food Code exception: a glass sensor or stem must be enclosed in a shatterproof coating, such as the coating used on some candy thermometers.

A metal probe is durable, cleanable, and able to conduct heat to the sensing element. The manufacturer must still design the complete device for its intended food and temperature range.

Its reach can help place the sensing area near the center of thick foods or deep containers. Confirm where the model senses temperature, because the active zone may extend beyond the tip.

Not by itself. Accuracy depends on the device, calibration, placement, sensing-zone depth, and correct use; stem length mainly affects reach.