The tampless temptation
I have always been interested in the theory that many support that one can prepare espresso without tamping at all and still produce results just as good as the results you get with any other form of typing. There are especially a lot of people who use lever machines who swear by this method or by the minimal tamping solution, where you tamp, but with almost no pressure at all.
It seems to make sense that this would work well and perhaps even not matter too much either way when you think about all the pressure that the water puts onto the coffee – far more than the 30 pounds of pressure that an individual would produce.
On the other hand perhaps the key is having the coffee already compacted some, so that when the initial water hits the puck it stays relatively uniform until the water has gotten up to pressure. The truth is that I do not think anyone completely understands the physics of the coffee and what is going on inside the portafilter.
There has always been buzz about the mythical(?) or at least mysterious glass portafilter that Illy built to allow them to understand better what does happen during an extraction. Here is a link to a conversation about it…
I think if you want to skip the tamp it makes sense to grind a little finer to produce a little more resistance that you are giving up by not tamping.
Now I am embarrassed that I have taken until today to try this myself. I have just pulled my first tampless shot. Remarkably with a slightly finer grind I am finding the espresso tastes almost identical to the shot I pulled a little while ago with the traditional 30 pound tamp. Now I confess that neither shot was perfect. I am using up some beans that are a little past their prime and you can tell as the shots were okay, but not great. I’ll have to try this again with fresher beans to confirm, but so far it seems to indicate that yes tamping can do damage if done wrong (for example dramatically tilted), but it doesn’t add much of value even if it is done right.