购买新鲜烘焙的咖啡豆。 购买咖啡研磨机，或者在店里磨好咖啡豆。 使用优质的水。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
If you can’t purchase it directly from the roaster within a week or so of it being roasted, opt for a vacuum-sealed bag from a reputable national coffee-bean roaster. If possible, choose a burr grinder in place of a normal blade grinder. For best results, grind the coffee fresh right before brewing each day.  Experiment with different ground size. Although finer grounds are generally preferred, they can result in a bitterer brew than coarse grounds. Many people recommend that you aim for grounds