If you've cooked a turkey you've probably seen a pop-up meat timer. These nifty devices are designed to pop up when the bird is done. But how does it work? This STEM investigation will answer that question and give the kids something to do while you're busy in the kitchen preparing for the feast.
This post contains affiliate links, meaning I will receive a small commission (at no additional cost to you) if you make a purchase after clicking a product link. Please see disclosures page for more details.
|Photo by M. Rehemtulla [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons|
Background Information: Turkey STEM Investigation
Here is the background information, or "spoiler", for this investigation. Depending on how open-ended you would like your student's or children's investigation to be, you can feel free to divulge this at the start, or let them make hypotheses of their own before sharing.
Inside a turkey timer is a thin piece of metal. The metal is a combination, or alloy, of lead, cadmium and bismuth. This alloy melts at a specific temperature, which is the same as a turkey needs to cook to, 180 degrees F, or 83 degrees C. When the piece of metal melts, the "pop-up" part of the timer is released.
To investigate pop-up turkey timers in action, you'll need the following supplies:
- pop-up turkey timers
- pan or beaker
- candy thermometer or probe thermometer
- oven mitt or heat resistant gloves
- stove or hot plate
- a turkey! (optional for Thanksgiving day extensions)
|by Freddyz at the French language Wikipedia [GFDLor CC-BY-SA-3.0], via Wikimedia Commons|
When the red part of the pop-up timer pops, record the temperature of the water. How accurate was the timer?
Try it again- to reset the timer, pull it out of the hot water and push down the red part. Allow to return to room temperature. This will solidify the alloy inside once again. To speed up the process, hold the timer closed in ice or ice water.
What do you find in subsequent trials? How consistent is the timer? Does it lose its effectiveness when it's been used more than once? Be sure to record all of your results.
Extend this activity on Thanksgiving! Here are some ideas:
- When you are cooking the bird on Thanksgiving, watch for the timer to pop. When it does, use a meat thermometer to check the temperature near where the timer is inserted into the bird. How does this compare to your experiment?
- Engineer your own pop-up thermometer model with this lesson idea from the National Science Teacher's Association.