Whether it be a lid for a rice cooker, slow cooker or traditional pot, one design feature stands out: a small hole.
And the purported reason for the hole varies depending on where you look online. In December 2023, for example, an X user floated the idea of it being used for thermometers to measure food temperature.
Can't describe how dumb I feel not knowing before today that this hole in the crockpot is for a thermometer pic.twitter.com/aBkmhJudsj
— Joe Flateau ??? ??? (@joeflateau) December 25, 2023
In the comments, users questioned whether that was really the purpose of the hole — which, according to listings on retailers like Amazon, is called a "steam-vent hole." We also found claims that the design feature prevents glass lids from rattling or shattering or equalizes the pressure between the inside and outside of pots, preventing lids 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. In early 2024, 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 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 said the holes vented a bit of steam out, prevented the pot lid from rattling and equalized air pressure between the inside and 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.