Thoughts on Espresso Preparation

I was wondering, as I do, about "polishing" the espresso before brewing. For all those that aren't baristas or at-home-baristas, after you pack the coffee into the brewing device (the portafilter), many spin their tamper to "polish" the top of the espresso. The question, of course, is why?

Before that got to me, though, I was wondering about proper polishing technique. Pressure or no pressure? Back and forth or unidirectional? 360, 580, 720 degrees around or just a little teaser?

I wound up here. I can't post on Coffeed (I'm not part of the club), but I do read it from time to time. Basically, what I learned from this thread confirmed in my mind the number one rule of espresso preparation:

Everything is relative.

Does it taste better with a pressurized spin? Then do it. A convex tamper? Then do it. An expensive tamping grinder? Then do it. No spin? Then do(n't) it. Digging your finger into the middle like a mole? Then do it. With little bits of hair? Then due it. With yellow soda? Then Dew it. And so on.

The strange thing about espresso, and one of its most wonderful qualities, is that it is a mystery, even to those who have worked with it for a long time. What is polishing for? Maybe to lock in the oils, maybe to develop an intricate architectual framework for water passage, maybe to keep the puck clean, and maybe for nothing. There is no scientific basis for any of the conclusions, except taste. That fickle, subjective, allusive, elusive property that snagged me in the last post.

It makes it hard to train folks, however. It takes awhile before someone is ready to start experimenting with their technique; a lot longer to break habits (over and over again). The uncertainty is hard to deal with. Especially when there are so many other factors that go into making a decent, not to even mention an excellent, shot of espresso.

The one factor that I didn't notice having mention in the thread was one of blend. Do different beans, roasted at different levels, need different preparation techniques to bring out their best? I guess this relates more to the last post, but it is something that should be considered.

Here's to chasing that delicious shot! Bottoms up.