OK – many of you are aware that I became an Espresso geek – well more or less. As many home baristas I also ended up with an affordable Rancilio Miss Silvia. Of course, not the ultimate machine like a LS S1 or GS3, but if you learn how to treat her, a very very good machine. With some modifications she can even beat machines worth two or three times.

As I got Silvia, I though, OK – easy going now – just start producing good Espresso. WRONG :)

I had to learn that with a more professional machine (compared to my old machine) all the variable parameters are much more important, and THERE ARE problems :) Just to list some of the things you have to keep constant to allow reproducibility:

Beans & blending
• Roasting
• Grinding (grain size & equal distribution of grain size)
• Tamping needs to be constant (e.g. always 20kg)
• Constant temperature of brew-head from shot to shot
• Predefined (90-95°C) and precise (optimally +/- 0.5°C) brew temperature
• Constant pressure (8 bar)
• Constant flow rate
• Result of about 25ml at around 65-75°C in a nice cup :)

Changing these variables to constants doesn’t mean that the resulting Espresso is good … that’s then the right combination of those parameters, but at least you can reproduce your beverage.

GRINDER

The first, most important and (not always) most obvious thing: you need a good grinder. I have the simplest solution (Demoka M203/M205) which is officially known as the only good grinder at a price level below 200€.

Update June 2006: I have upgraded to a Rancilio Rocky SD – wow – what a difference in terms of quality for only a bit more money. In retrospect I would say: never buy a Demoka if you can afford the Rancilio Rocky. It is just solid, precise piece of engineering! The reason for the upgrade was that my Demoka grinding gear was defective and it was replaced … which took over a month and in the meanwhile … :) :) :)

PID

If you search for “PID SILVIA” you’ll get a view thousand hits. You get some positive and some negative recommendations, but overall the modification is highly recommended. I also like to tinker and I disliked the temperature surfing method to allow constant brew temperature. The principle is fairly easy; you use an industrial temperature PID controller which allows Silvia to keep temperature at at least +/- 1°C, which is ultimately better than the hysteresis of about 20°C without this modification. Some things I did different compared to most instructions: Use of a thermocouple Type T and mounting it close to the thermostat at the boiler water inlet, so the PID is immediately responding to water intake. After some parameterisation of P, I and D, the machine is back at my desired temperature after finishing the grinding for the next shot – WOW – what a change!

So the question is, whether this helps producing better espresso? I have to say it helps producing not better espresso, but you can keep the procedure of brewing espresso constant at a specified temperature which indirectly leads to better espresso. So you can direct the Espresso extraction and get a feeling of how it tastes different at 2°C more or less (YES, even a beginner tastes the difference!).

I was wondering why my coffee tasted still sour, partly bitter, even at temperatures above 97°C, which is even the upper limit for some exceptional beans. Well, the BIG CHANGE in Espresso quality was a complete different, from my point of view neglected modification: pressure!

PRESSURE

This pressure modification was the final breakthrough. I have a portafilter with a pressure gauge. Guess what? I had 12 bar and accepted that for almost half a year. Now I changed it to 8-8.5 bar and man, what a difference. Dry puck, neat clean extraction, no channelling, great great great great (x1000) taste – like with a complete different machine! This makes a huuuuuge difference, much more than I ever imagined.

Again: This makes the biggest difference I’ve ever experienced!

CONCLUSION AND FINAL REMARKS

DO the pressure modification, it only takes you a view minutes! From my point of view the most important mod if your machine’s pressure is running too high.

DO the PID modification, it will result in a good temperature stability and reproducibility!

NEVER use the original single basket! If you need to use a single basked, get the LM basket! It makes a HUGE difference, although the shots are still not as good as with the double Rancilio basket!

The option of a 2nd PID for the group-head is unnecessary, at least for me. I did some measuring of the brew temperature at the water outlet of the group-head. After half an hour warming up and one clean water shot before you start grinding, everything is at the desired temperature :)

Finally get FRESH (!!!) roasted beans from your preferred roaster (forget about preground or old coffee, you won’t need a Silvia for that!) and enjoy your coffee!

LINKS

• CoffeeGeek
• Kaffee-Netz
• Home-Barista