The (Apparent) Importance Of Coffee Lids

I’m a coffee fan and since my wife and I purchased a Breville Barista Touch Impress for ourselves Christmas of 2023. We’ve been making espresso-based drinks at home nearly every day. It’s straightforward to use, has a built in tamper, has auto milk foaming, but can also run in manual mode.

I take a latte, cappucino, or flat white to work with me in the morning using either my Hydroflask or Corksickle travel mugs but one time I was in dire need of a mug and just snagged a regular old pint sized glass and took it with me.

When I took an open-top glass I realized that I normally drink the coffee goodness well before it get’s meaningfully cold. Often, I’m polishing off the last dreggs soon after daily standup meetings (approx 8:45). This quick consumption means that heat loss isn’t too much of a worry, I’m plenty used to coffee cooling down in to-go cups and it didn’t seem much different.

So, I switched to just pouring my drinks into one of the same travel mugs and leaving the lid at home. I was coordinated enough not to spill, drank the coffee before it got cold, and had one less part to clean.

I started noticing something: the foam would dry up along the side of the mug as I drank it. I considered this a draw back to drinking coffee in the winter since a coffee cup does the same thing with a good cappucino in it.

But, this last week I decided I’d like some warmer-than-normal coffee and what did I find…

Not only that, but the condensation on the lit pointed me to a revelation: The lid is useful not only because it keeps the coffee inside, it also maintains a humid environment which either makes it slipperier or less likely that the foam will condense/dry on the walls of the mug.

Further investigation is required, maybe a humidity chamber for an open top mug while it’s not being drunk.