Ever wonder why a French press is so annoying to clean? After a few brews there is an accumulation of stuff in the filter.
That stuff is coffee. Specifically it is oil.
When you brew in a press there is no paper doing any work — the plunger screen is a mesh, and mesh does not catch oils. They collect in the screen, they go rancid over days and weeks, and then they sit in the path of every subsequent brew. If your coffee has developed an off taste that you cannot pin on the beans, this is very often where it lives.
The easy way
Most presses are dishwasher safe, and this is the part people do not realise. Take the plunger assembly apart — it unscrews into three or four pieces — and put the parts in the cutlery basket so they do not scatter across the machine.
You do not need to do this daily, or even weekly. Once or twice a month is the recommendation. Between times, soak the screen in hot water for a few minutes after each use and the oils never get the chance to settle in.
That is the entire article. It is a two-minute job that fixes a problem most people blame on their beans for years.