Afternoon Coffee has an "Edge"

[MikeW]

(Hope this is the right category for this subject.) Here's a problem I've been working on for a while. When I make coffee in the morning it almost always tastes wonderful and has no flaws. But when I make it in the afternoon, my coffee has a slight bitter edge to it. Same for the evenings, a slight bitter edge.

This has happened with two grinders I've used over the months, a Bodum Bistro Burr, and Mazzer Mini. There have been rare instances where afternoon coffee is as smooth as morning, but I think it's happened only twice. This is extremely consistent.

Suspecting the grinders I've tried "sacrificing" a few beans to flush out the path before making a cup. No difference. Cleaning out the grinders made no difference. I thought it might be caused by opening the bean jar "a second time" during the day, but it happens when I open a different jar in the afternoon.

It might be the humidity or some other factor involving stale grounds that I haven't accounted for. I could also try waiting til afternoon to make the first cup. That's going to be hard!

Anyone else find afternoon coffee to taste not as good?

-Mike

[asfolks]

Yes, even my second cup in the morning does not taste as good as the first. I always assumed it was my taste buds and the interference of competing flavors on my palate.

[bigbells]

Although I don't personally experience a decrease in tastefulness, I do experience a change. The first cup in the morning, when I'm breaking my fast, encounters hungrier taste buds.
With the current heat wave, hot coffee in the afternoon is on its face not a necessarily appealing proposition even if one is in an air-conditioned environment because the human body has warmed up as the day has progressed. Even when I'm cold, coffee so hot that it must be carefully sipped is too hot for me. This morning's pot was poured back and forth repeatedly between the carafe and my mug until it had cooled enough that I could take big sips. By the time the sun is high today, I won't want coffee that's too warm to gulp.

[MikeW]

I hear what you guys are saying. But, my second morning cup, taken after breakfast, does not have the bitter edge; whereas in the afternoon or evening, that bitter edge is always there.

I agree it may well be a matter of perception, but I think there's a chance it could be something different in the coffee itself.

-Mike

[arjaybee]

I had a similar issue where cups I brewed at the office weren't quite as good, even when I tried to control for every variable. I eventually figured it out.

The tap water at the office is terrible. Even though I wasn't using it to brew my coffee, I was washing my mug and Aeropress using the tap before brewing with bottled water. I didn't bother to dry things off and even the small pool of water in the bottom of the mug seemed to be enough to effect the taste just enough that I noticed.

I'm talking REALLY nasty tap water, btw. I even tried a Brita water filter and even the filtered water tasted bad and would leave a white residue when it evaporated.