What I'm going to write today about is a product that had really help me to realize the full potential of my espresso machine, the La Pavoni lever espresso machine. It is the Orphan Espresso temperature sensitive strip: http://www.orphanespresso.com/Pennys-Hot-Shot-Group-Strip-Thermometer_p_2133.html
The temperature strip is a flexible liquid crystal that can be glued onto the bell of the group head of direct lever machines such as the La Pavoni and the Cremina or the Elektra Microcasa. The range is from 90-120 degree Celcius in five degrees interval or 194-245 degree Fahrenheit in about nine degrees interval.
So what is the big deal about this? Why such a temeperature measuring device with such a large margin of error be of any of use to us in making the shots better? Afterall, there are PID espresso machine that can heat and deliver water exactly +/_0.1F ! It is indeed hard to explain the exact reason, but this is analogous to how Heat-exchanger machines work, the point is to provide a reference of what is a hot shot, normal shot or cool shot. The La Pavoni (and I might be generalizing to include other makes such as Cremina or Microcasa) were not designed to delivered exact water temperature, rather, they were designed to extract flavor from coffee group efficiently, quickly and with a great sense of style. As such, there are limits in term of the type of coffee and roast you can expect these machines to perform well.
With this temperature strip modification, the temperature managment ability of the Pavoni approach that of a good HX espresso machine. I'm able to pull a cooler shot, normal shot or relatively hot shot; this make dialing in different coffee really easy. My routine is the following:
-Turn on machine
-Release false pressure
-Flush until I see the first bar (90C) barely lit up, the flush water warm up the demitase as well.
-Put in tamped coffee basket and pull the shot, the temperature indicator will shoot up to the second bar or possibly barely light up the 3rd bar.
For cooler temperature, I flush less so that I don't see any bar light up, for hotter tempearature, I flush so that the first bar light up all the way. In my opinion, this modification had greatly increase the flexibility and usability of the La Pavoni. It certainly removed a lot of frustration I had before with this machine. I think this is something that any Pavoni owner must get!