I kept all grounds in a ziplock freezer bag in a dark room-temp cabinet. As I went from freshest to least-fresh I found that there were flavors missing and more bitterness and acidity.
What I meant about wine is that there is a lot of stuff in the wine world that people obsess over, but is not detectable by even experts. For example, the differences in regions of origin, price of the bottle, etc. I'm not saying that everything in the wine world is BS but there is plenty of if. Even experts have been fooled with food coloring into describing white wines with adjectives normally used to describe reds.
One is whether wine experts are able to detect certain flavors or even figure out the grape variety and origin of a certain kind of wine.
The other is whether in blind tastings cheap wine is consistently rated as inferior to expensive wine.
I've found people in the wine industry can figure out where wine is from with surprising accuracy. But their skill is not in the least based on a judgment of how much they like the wine. It's about having an encyclopedic knowledge about which wine is associated with which flavors and production techniques, and then matching up what your nose tells you with one of those taste profiles in your head.
Once you know what type of wine you're tasting, you can infer the price category:
* French Pinot Noir is generally more expensive than New Zealand Pinot Noir.
* Wine that's been in new oak barrels (evident from e.g. vanilla and toasted flavors in the wine) is more expensive than wine that hasn't been.
* Wine that tastes only of red and black fruit is probably young and thus cheap, wine that tastes of weird things like truffles and what-not is likely to be older and thus more expensive.
* Sweet white wine which tastes like marmalade and honey and nuts has a good chance of being made from grapes with noble rot, which are picked individually, berry by berry, and thus result in incredibly expensive wine.
* ... and so on.
So the link between quality and price in wine is very tenuous, but that doesn't mean professionals "can't tell the difference". They can.
Exactly so. I just wanted to note that "expensive wine doesn't always – or even often – taste better" and "experts can reliably spot the difference between cheap and expensive wine" are not incompatible statements.
What I meant about wine is that there is a lot of stuff in the wine world that people obsess over, but is not detectable by even experts. For example, the differences in regions of origin, price of the bottle, etc. I'm not saying that everything in the wine world is BS but there is plenty of if. Even experts have been fooled with food coloring into describing white wines with adjectives normally used to describe reds.