There are four things that factor into making great coffee. Each of these is necessary to achieve truly great coffee (not what you get at the truck stop). The emphasis here is on espresso-type coffee, or the epitome of what the coffee bean is capable of (I know, I'm ending a sentence with a preposition. I don't care.). If you are in the search of the "god shot", the following should interest you. If however, convenience is a higher priority than quality... well, I'll stop short of recommending instant coffee, but other than that - hey, do what you want. As much as I love Ruth's Chris steak house, I still eat at McDonald's.
- Miscela (blend) – You have to start off with the right ingredients. This could consist of straight, 100% Jamaican Blue Mountain. I couldn't fault you for that. I love the stuff. Cheap (i.e. Folgers, Maxwell House and the ilk) coffees are often a combination of lower quality beans, for example, low-grown Brazilian beans that are mass-harvested, with better quality Arabica beans to provide better flavor. Big companies change their blend throughout the year in an attempt to maintain the same flavor while using what is available/economical at the time. Premium coffees are hand-picked at high altitude (known sometimes as "hard bean" and do not include sticks and stones in them. This is another good reason to buy whole-bean: you see what you are getting. Mass-harvested beans include many immature and overripe beans in addition to ripe ones, which does terrible things to the flavor. Coffee needs to be fresh. Ideally you will be drinking coffee that was roasted within the past week, and ground within the past few minutes.
- Macinadosatore (grinder-doser) – This really doesn't receive the attention it deserves. It is possibly more important than the espresso machine itself. A consistent, adjustable grind is required. Ristretto requires the finest grind, next espresso, drip-type machines need a medium grind, and the coarsest is for the french press, or perhaps, Turkish coffee. I recommend the Mazzer Mini, which is what I have. A doser is a grinder accessory that consistently delivers the same quantity of beans. Hopefully.
- Macchina espresso (espresso machine) – This supplies hot (about 202F, 95C seems to be preferred by Americans, I hear of 190F, 88C being used by Europeans. For a french press I personally use 195F, 90.5C) water at elevated pressure (about 130 psi, or 9 BAR) that is forced through the portafilter (that thing you put the grounds in - and I don't mean the fertalizer pile). If a cappuccino or latte is desired, it should also include a frothing spigot for milk, which is used to heat (to about 150-155F, 60-68C) and froth the milk. Actually, I prefer to use heavy whipping cream (not whipped cream, that's quite different).
- Mano dell'operatore (hand of the operator) – Even with all the automatic features that so many machines have, a skilled and well-trained barista is essential. Not a coffee jerk.
This is of course a quick introduction to the basics of quality coffee making. I don't pretend that reading this will you make you the best coffee-preparer in the world. But hopefully it will help and point you in the right direction.
update: I don't eat at McDonald's anymore. That whole "Super Size Me" thing kinda freaked me out.