My favorite tech news site, Ars Technica, recently published a short article called The science behind a good cup of coffee. While the entire article is worth a read, here’s a couple of my favorite bits.
On this site I’ve said that darker roasts have less caffeine than light roasts before, but that might not be the case:
Contrary to some common beliefs, the amount of caffeine in the beans doesn’t change that much with roasting. Some studies have reported slight decreases in caffeine in darker roasts, but some have found no differences.
That said, the article does validate my preferences for espresso:
As for taste, researchers have noted that espresso has some of the richest flavor and creamy texture, owing to a layer of emulsified oils that create a homogenized foam over the liquid. Those oils are likely cut down in drip coffee—thanks to paper filters—but may remain (although not in homogenized foam form) in boiled or steeped coffees.
Anyway, if this science-based approach to coffee interests you, give the whole article a read for more details about what’s in your coffee, the differences between different types of beans, and — of course — differences between various brewing methods.