Good day,

I was able to spend some more time learning the nuances of pulling shots on my Europiccola this weekend, as well as dialing in my HG-One. I am learning the subtleties of the grind and surprisingly the tamp, which has a big effect.... and of course the freshness of the bean. I hooked up a multi-meter for thermometry of the group, which also has a big effect. (is there anything that does not have a big effect? LOL) I also upgraded to the Caefelat bottomless portafilter. All these variables are independent and I am learning how to control each one and trying to combine them all for a great shot. This is much more difficult than most people newbies realize. I still have not pulled a great shot, but am getting closer. I was using CC Big Trouble that I purchased locally for practice and it was roasted well beyond 2 weeks ago. I figured if I could get this to taste ok, I am doing well.

After a few attempts and some cool down time, I finally got decent crema (see pic). I pulled the shot when the group temp was 197 deg F, but it shot up to 205 def F. I knew I had dial in the grind and tamp when the lever required a bit of force and the shot took much longer than I have been pulling. It looked great, but was quite sour....or was it bitter?....but it reminded me of most shots I have received from Starbuck..et all. Far from the drinkable shots that I have read about here.

So now, I need to solve the bitterness or sourness. Perhaps it was the beans themselves which were not fresh. Perhaps the group temp was too high. I have all the right tools, now it comes down to time and patience.

I gradually came to the conclusion in the years that I have had second generation La Pavonis that one should never lock down the portafilter until the handle is up and near the point of releasing water and steam. For the first shot it is best, as I have pointed out in earlier posts, it is best to have the portafilter off and the cup next to it. After being sure the machine is well bled and that the top of the group is free of air, one can raise the handle and let a bit of water and steam escape, lower it enough just to stop it and then IMMEDIATELY put the portafilter in place and lock it down. Put the cup under it and pull the handle down just enough to allow a few drops of espresso to emerge, raise it all the way to the top immediately, wait only a second or two and pull the shot. The REAL important thing is what the temperature profile of the shot is. You cannot do anything about it after you have pulled the shot, but you can do things to change the next one. You can measure the temperature of the espresso as it emerges from the machine with an infra red thermometer. You will need an assistant to do this, and you need to experiment exactly where the sensitive area is relative to the IR thermometer laser. The first espresso will emerge at about 50-60 degrees and then shoot up into the 80s, and, for an ideal pull, I like it to end up as close to 93 as possible at the end. If you have done all correct, the handle should NOT move up when you release it after making the pull. That means you had a lot of air trapped inside. (I made a thermometer well spout that gives essentially the same ability to measure emerging espresso temperature, it gives essentially the same results as the simpler IR thermometer.)

After the second shot one always needs cooling. This can be accomplished by many means, simplest is probably drawing water into the group with a ramekin between shots.

The grind is terribly important. The time since roasting is important. Ambient temperature matters a bit too. The one thing I found that introduces consistency is NOT to lock down the portafilter until the handle is near the position of releasing hot water. Pulling air through the puck often fractures it. That is the usual cause of "gushers", I think.

I never use a wired thermometer on my La Pavoni. It is brass and has a coating of high emissivity. You can scan the group with such a device and find what temperatures are in different points on it. With a chrome plated one, you will need to stick tape on places you want to measure that way. I only use thermometers when the results are not what I want. Otherwise I rely strictly on timing because physical properties of matter do not change!

Hi Robert, I really appreciate all the information you and others provided. Without, I never could understand this thing.
Whats the problem if the handle move a little up when finished the shot? I couldn't understand the effect to taste.

If the handle should move up at the end of a shot it means that there is a lot of air trapped below the piston, the end of a spongy pull. When air is trapped here it reduces the shot volume, but the problem is that it does so erratically, so that the shot volumes will vary. It is particularly prone to happen when the group is not hot enough for the incoming burst of steam to drive out most of the air before the top of the grounds becomes covered with water. If you want a "shorter" shot you can remove the cup before the end of the pull! If one raise the handle until a bit of steam is released, stop the steam release by lowering the handle just a bit, and then attach the portafilter and raise the handle all the way, most of the space under the piston is then water vapour instead of air.

With pressurestat machines one can use the "olive jar test" to be sure the group is properly bled:

Bleeding Pressurestat lever machines. (Especially 2nd gen La Pavonis)

Hi Mike:

Sour is like the juice of a lemon, bitter is like the lemon rind. Often these get confused if you have a high brew ratio, where the amount of water is slight compared to the amount of grinds used. This gives you a shot that's "in your face." This classic post has that information.

Espresso 101: How to Adjust Dose and Grind Setting by Taste

The variables you are describing more broadly are all included in the Four M's.

If you are using two week old beans, they will channel, the flow won't be right, and it won't taste nearly as good as it can. You really, truly need fresher beans, the "miscela" item in the Four M's.

"My coffee is stale..."

Please read this, if you haven't done so yet.

/espresso-guide.html

Thank you all once again for the good info. It is hard to keep track of it all as you are doing it....just takes practice.

It's no wonder people go to automatics! ; )

Thanks a lot. Very clear now.
Another question, during pre infusion I always get drips from the edges first.
But later the pour becomes normal and cone is formed.
Is it normal?

Initially espresso will begin to emerge from all of the holes on the bottom of the filter basket. Until it gets wet drops will tend to form from where it has emerged. When the flow becomes greater the flow will consolidate and move toward the centre along the surface of the filter basket before it flows down.