Its OK, I'm a self-confessed coffee ponce
Happy to admit it, and certainly happier to describe myself as that, than as a 'true connaisseur'
Your machine can control dose, grind and it can control the amount of water put through the coffee, but it can't taste the coffee and change those variables accordingly. That is the difference.
If I took three different coffees and pulled all three on the same variables, got you to taste and then allowed me to tweak you'd be surprised at just how much can be done.
Yer standard Italian style coffee (medium roast, heavy on the Brazil's with a bit of robusta thrown in for body and crema) is actually really easy to extract and you have to be pretty ham-fisted to end up with something bad in the cup. This is possibly the key reason why coffee in Italy is consistent, and consistently good. However, its never amazing and for that you need to go down the road of varietals that are harder to extract.
I've got three on the go at the moment, a Sumatran Jagong, an Ethiopian Yirgachef, and a Rwandan. The yirg need a fine grind and a lot of water through it, otherwise its like a mouthful of oily acid. The Jagong needs a fine grind, so that it comes out in drips, and you nneed to cut the shot at about half the volume of the yirg (ristretto) or you lose the sweetness. A machine cannot know this.
Its really weird how doing this and getting a sense of the coffee and how to best extract it seems to come naturally to me now. This wasn't always the case. It is a bit of a black art, and it is interesting how uncomfortable some people are with discussions like this and want to deny that the person doing the grinding, filling, tamping and extracting has much of an impact. I certainly am guilty of having fallen in that camp a while back.
