In one of the posts we discussed about the shelf life of coffee beans.

The deterioration of shelf life (in simpler words, freshness level) of coffee beans speeds up as it moves from green bean to roasted bean to ground form. Once the roasted coffee is broken down to the ground form, the freshness of coffee goes downhill in matter of time.

Exactly for this reason, we recommend home brewers to invest in a good grinder (either a hand grinder or a manual one) so that they grind the coffee beans just before they want to brew their cup. 

Further, we recommend buying a burr grinder rather than a blade grinder. Burr grinder ensures the uniformity of the grains once coffee is ground. With blade grinder, one may experience huge variation in grind size in a single batch. With burr grinder, it is easier to accommodate right grind size suited to a particular brewing method. 

This will eventually ensure we get to experience the aromatic coffee with a balanced taste. 

In case, one is interested in getting into the hassle of grinding coffee everyday, they should order ground coffee in small quantities in shorter time intervals. This will ensure that the coffee gets consumed within shorter timeframe when all the chemistry of coffee beans in still intact. 

Coffee is still edible when old but the freshness level will change once it is kept in ground form for long time (with whole bean, deterioration of freshness takes slightly longer time). 

Cheers