Is That Little Hole in The Lid of Your Slow Cooker Meant for a Thermometer?

What's up with those little holes in glass pot lids?

Published Jan 17, 2024

 (Jack Izzo)
Image Via Jack Izzo

Let's set up a hypothetical situation here: It's cold out, and you break out the slow cooker to make a delectable stew. But once you start the cook and put the lid on top, you notice a little hole in the otherwise all-glass lid. "That's odd," you think. "Why is that there?"

It’s a small cookware design feature that’s puzzled us all, and in December 2023, a user on X posted a potential solution: a picture showing a meat thermometer fitting perfectly in the hole. The post went viral, gathering over 20 million views.

But users in the comments questioned that usage. So really, why is that hole there?

Searching on the internet, Snopes found plenty of other explanations. Listings on retailers like Amazon referred to them a steam-vent hole. We also found claims that the hole prevented glass lids from rattling or shattering, or that it equalized the pressure between the inside of the pot and the outside, preventing the lid from physically popping up.

With a variety of theories in our back pocket, we figured the best place to start answering the question was by asking the people who make such lids. Snopes reached out to five cookware brands — Hamilton Beach, Crock Pot, Calphalon, OXO and Caraway. While Hamilton Beach and Crock Pot make slow cookers, we also queried companies that make stovetop cookware, since those lids also often feature a hole.

The answer? All of the above, as it turns out. Newell Brands, the parent company of both Crock Pot and Calphalon, did not respond to a request for comment. Neither did Caraway. But both Hamilton Beach and OXO provided answers.

An OXO customer service representative told Snopes via phone call that the holes vented a bit of the steam out, adding that it prevented the pot lid from rattling and equalized air pressures between the inside of the pot and the outside of the pot.

On an FAQ post, Hamilton Beach also noted that the hole in the slow cooker lid “allows excess steam to escape to avoid build up.”

However, a customer service representative for Hamilton Beach said that some, but not all, of its slow cooker models contain a hole specifically designed for a thermometer, and some models even come with a temperature probe.

But regardless of whether your slow cooker contains a hole for a thermometer, Snopes could find no evidence suggesting that inserting a thermometer in a vent hole changed the quality of the food, or adversely affected the functioning of a slow cooker.

We found two potential downsides in those cases: plugging the hole with a thermometer might make water boil over faster, and depending on the type of thermometer used, the reading of the food temperature could be inaccurate.


Beach, Hamilton. “Top 10 Slow Cooker Questions, Answered.” Hamilton Beach, 25 June 2020,
Crystal. “Should Slow Cookers Have a Hole in the Lid? What Is It For?” Ceramic Cookware Hub, 8 May 2020,
Hamilton Beach FAQs. Accessed 10 Jan. 2024.
“Https://Twitter.Com/Joeflateau/Status/1739337419827081253.” X (Formerly Twitter), Accessed 10 Jan. 2024.
“Slow Cooker with a Hole in the Lid.” Reddit.Com/r/Slowcooking,
“Why Do Lids Have Holes in Them?” Reddit.Com/r/Cookware,

Jack Izzo is a Chicago-based journalist and two-time "Jeopardy!" alumnus.

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