Freshly ground coffee, how fresh should it be? I 'know' that freshly ground coffee is the best there is (within the quality of the beans, that is).

The question is whether this is true. Freshly ground coffee smells great, but does that affect the flavor after brewing? How long do these volatile flavors or smells last before the coffee goes 'stale'.

Can anybody (experts) taste the difference between freshly ground and brewed or not so freshly ground coffee? If so, what differences can be observed?

Edit as per talon8's link:


Freshly ground: brighter acidity, richest flavor.
9 hours: very similar to the freshly-ground coffee, although a bit mellower; less “bright” notes.
24 hours: some of the fruity flavors have faded; a bit less flavor in general.
7 days: duller, significantly less flavor overall.


To the people that notice the difference in taste, do you agree with these observations?
Coffee begins to lose its flavour and freshness as soon as the roasting procedure is complete. Whole beans are best used within a month of roasting. The best way at looking at ground coffee is that it is similar to the whole bean, only with a whole lot more (pardon the poor english) surface area. That means that any of the breakdown that occurs to the bean will occur exponentially faster with a grind. You should always grind beans for each use, if you wish to have maximum flavour.
I am no expert, but I can tell the difference between freshly ground beans (like my wife and I do), or not so freshly ground (like my in-laws do).  I am no scientist, but the older the grind, the 'flatter' the flavour. It is definitely noticeable.