What makes a bean good?

I had an odd request yesterday when I walked (ok, trudged- it was 8am and I'd been up since 6), into my local cafe. The barista had found out where I worked, and what kind of beans we use, and then he asked me to buy him some. "What?!" I thought, "He works in a cafe that uses perfectly nice beans- why would he want to spend money on the ones we sell? And at almost $40 a kilo at that?!" He must have been huffing too many espresso fumes. I know they do funny things to my brain by the end of the day.

He explained that he likes the taste of Havana beans (the ones we use- roasted by some crazy guys in Wellington) more than the ones they use at his cafe, and he wanted to take Havana away on holiday with him at Easter.

Confession time: I don't like Havana beans much, even though I REALLY want to. This isn't because they aren't good quality- they're just different. I find them bitter, other people find them fierce.

Anyway, so that got me wondering: what makes a good bean?

You need to start with Arabica (or the rarer Typica or Bourbon) plants, of course. I'm not being a snob here either- it's well understood that Arabica is bred for taste, and Robusta for caffeine content and mass production. Nothing personal.

The beans should be grown at the right altitude (this helps ensure that the they don't get too hot or grow too fast and absorb heaps of water- same thing as when strawberries take in too much water and taste bland).

They need to be picked when they're perfectly ripe, and handled carefully so that they arent damaged.

One coffee writer compares coffee cultivation to raising kids- as long as you use the right plants, the beans will start out good. It's then up to the people handling the beans once they're separated from the tree to ensure they don't get damaged (e.g. Don't throw them around too much or they will get bruised...).

But what about after they head out into the big, wide world?

Individual roasters might start out with similar beans- or even, perchance, beans from the same plantation. Yet, something happens which makes Havana beans more preferable to my barista than the ones they use in his cafe, and it has little to do with the initial product.

Both use Fair Trade beans from South America (and yes, there are differences between one coffee-growing region in S America and another, but we're not going to go into that much detail). Both roast in large batches, and both do so here in New Zealand. His cafe's brand vaccuum-packs their beans, Havana doesn't (actually, they would if our owner was willing to pay for it...).

Havana, however, have built their own custom European-style hot air roaster (pictured here), while the other company uses a traditional drum roaster (which, Havana argues, over-bakes the beans). The difference is basically that Havana's beans cook more evenly, and retain more moisture. But whatever, really- I still prefer the other brand's taste, for some reason which is probably best explained by personal quirk rather than scientific analysis. Maybe I like "over-baked" beans, and my barista likes his "moist." What implications this has for my future parenting style, I remain unsure...