Bezman wrote:Another thing I noticed is that sometimes the puck comes out pretty dry after the shot and fall out of the portafilter easily and sometimes it is soaked a leaves a lot of sticky grounds stuck inside. What causes this?

For the second time this month, I will be lazy and repost my reply from Dry puck below:

matt1203 wrote:what make a dry puck ?

If the puck doesn't make contact with the dispersion screen when the coffee expands, the puck's surface will be wet with a sandy/lunar-esque texture. As long as the puck is consistent, wet or not, it's fine. For reference, see prior discussions 1, 2, 3, 4, 5, 6, 7, 8, 9 ... or just puckology in general. If you want a dry puck, dose a few grams more and/or wait longer before removing the portafilter.

allon wrote:There are a couple of things that can be diagnosed from a puck...

I've not discovered a correlation between the appearance of the puck post-extraction and the taste of the espresso. Moreover, there's nothing inherently wrong with small puddles of water on the puck's surface, though it should be consistent from shot-to-shot. That is, if you see big puddles one time, dry as sand the next, that's a problem. But if the puck's surface looks and feels basically the same each time, I believe you've exhausted the value of puckology.

That's why I am wary of claims that one can see evidence of channeling on the puck's surface. Afterall, most espresso machines have 3-way valves and they depressurize from 130 PSI to 0 in an instant. I think that any fissures are as likely caused by rapid depressurization as channeling during the extraction.

mitch236 wrote:Most likely your doses are varying and a couple grams are hard for the inexperienced to notice.

allon wrote:How about aiming for the best taste, regardless of the cleanliness of the screen? If you can get a clean screen without affecting the taste, go for it, but I would focus on flavor.

I agree with these replies and will add that I can teach the mechanics of espresso preparation in about 20 minutes. Identifying the source of shot-to-shot inconsistencies in technique is a little harder, but not much. Identifying the source of taste defects requires more experience, but thankfully there's lots of online documentation pointing to places to start (e.g., here and here and here, to name only three).

A scale is nice for consistency, but dosing by volume works too. The key is not to (unintentionally) compress the grounds when dosing. So, for example, dose directly into the basket until it's overflowing. If you're using a doser, pull the handle such that each portion drops along the perimeter of the basket (i.e., don't create a huge pyramid in the middle and then push the coffee around; you'll end up with more coffee in the middle due to settling). The video in Stockfleths Move for Dummies demonstrates this point. Once the basket is filled past the top, strike off the excess into the doser. This will produce the "standard" dose for that basket, typically 14 grams for a double. If you want to dose more, gently tap the portafilter to settle the grounds, then dose/strike off a second time. With practice, each tap will add approximately 1 gram.

My final piece of advice: Don't overthink it. While inconsistencies may be a bit frustrating, making espresso at home is like any new endeavor. It requires experience and the development of skills. Nobody I've known has ever learned to ski, skate, or ride a bicycle without falling a few times. You'll enjoy the learning experience more if you see these initial steps as the beginning of a journey.