I am often asked why it is my preference is to sell whole bean and not pre ground coffee. Put simply you wouldn’t go to the fresh fruit market and ask for fresh apples to be cut up and put in a bag? Would you? You would use a sharp knife to cut the apples just before you eat them?
Coffee in this instance is the same. As soon as coffee is ground the quality deteriorates regardless of packaging. On average it takes approximately 50 individual coffee beans to make a shot of espresso. These beans are ground into approximately 4.5 – 5 million particles! As soon as you increase the surface area of the coffee the quality will deteriorate. Grinding whole bean on demand as close to the time of extraction is the only way to ensure the coffee has the best chance of tasting great!!
Another draw back with pre grinding coffee is accuracy of the grind. With espresso coffee each espresso machine requires a different grind due to pump pressures, material construction etc… Also, temperature and atmospheric conditions play a part, therefore; pre grinding is guess work! Not a good way to get the best out of the coffee or the capital invested in your coffee machine.
In short… BURR Grinder. Cheers.