I never thought to buy such a serious coffee machine. I was quite happy with Silvia (Rancilio), but I got an unbelievable good offer for Brewtus 2 (almost half price, but cutting out warrenty which I don’t need – I can fix the electronics myself and the plubming are also standard parts). Brewtus is a dual boiler machine (1.5 l each!), providing rock stable brew temperature while having steam instantly from the second boiler ;)

The brew boiler is electronically adjustable in 1 ºC increments, allowing for subtle changes for different coffee blends and roasts. The temperature stability is further supported by an E61 system that is using a thermosyphon circuit to heat the grouphead.

All this makes it a big step forward from Silvia (single boiler with about 300ml, passiv group heating), especially in terms of consistency. Surely, milk drinks are very easy to serve now as well ;) In my opinion only the legendary LM GS3 can top that machine, but that is surely too much for an amateur! There are a few similar dual boilers around, e.g. the La Spaziale S1 or Reneka Techno, but both with a significantly higher price tag …

I fitted a new OPV (OverPressureValve) for Brewtus, that allows me to adjust the brew pressure to my own preferred setting. That part is available from BellaBarista in the UK, which have an extremely good reputation for their products and support. However, as far as I know the newest Brewtus II machines already come with a fitted new OPV that is adjustable.

You might hear some more news about Brewtus in the future in my coffee section :)

PS: Of course the roasting season outside has started, instead of roasting under the hood in the kitchen! Currently I try all sort of green beans from HasBean and also his very good blends. Today I roasted his Has Bean Espresso Blend and the Cop Of Excellence Blend.

So, we are all (I mean, we coffee geeks) well aware of many tips for the ultimate microfoam, e.g. follow these instructions at CoffeeResearch.org or this one at CoffeeGeek.

However, to become perfect microfoam with Silvia, you have to change some parameters as compared to a heat exchanger machine:

• Where to place the steaming tip? This is actually crucial, especially for the expansion phase: Hold the pitcher slightly beveled and put the wand directly towards the edge of the pitcher, but make sure that the milk starts spinning while you do so. Place the wand to the middle of the pitcher – and you won’t get perfect results. Touch one wall and perform your milk expansion and you’ll be surprised by the result! After expansion sink the wand and start turbulating as usual.
• The milk stretching/expansion phase shouldn’t be too long – as a rule of thumb stop expansion phase at about body temperature (40 ºC or 100 ºF). The final spinning/swirling of the milk needs to be a bit longer (up to about 65 ºC or 150 ºF) with Silvia, as she is not as powerful as heat exchangers. Another reason is if you expand the stretching phase you also end up with too much foam.

Enjoy milk frothing with Miss Silvia!

After using the coffee roaster for quite a while now and being very happy with the results it is time to do some refinement in terms of modifying the taste by various roasting profiles ;)

The questions I want to answer: Experiment No. 1: Find the best roasting time of my favourite green coffee blend. Experiment No. 2: Then using the favourite roasting level from Experiment No. 1 but roast with different profiles, e.g. no preheated vs. preheated drum and roasting temperatures (essentially longer vs. shorter roasts).

Experiment No. 1: Gene Cafe Roaster CBR 101, preheat drum to 250 degrees, roast 3 batches close to my favourite roasting level – with the HasBean Espresso Blend accordingly 16.5 min, 17.5 min (middle of second crack) and 18.5 min at 250 degrees. Cool down externally within 3 min to room-temperature.

The kind of roasting level I prefer from these experiments is just the right balance between not sour but not too (sweet)bitter. Therefore it works out quite well if I stop roasting just with the beginning to middle of the 2nd crack ;)

Experiment No. 2:
After many more roasts I think I have found my ultimate roasting combination for this particular blend. Using the HasBean Espresso Blend, preheat drum at 245 degrees and roast them to just the beginning of the 2nd crack at 245 degrees (here it was 17.5 min).

There is not more to say, one has to experiment with a variety of blends and various temperatures and times. It is a lot of fun and an amazing experience if you taste the difference and find the right balance …

Have you every thought about roasting your own Coffee ? Why not ? You can blend and roast your coffee according to your own taste from single high quality estate beans (use blended green beans for the beginning) yourself. You lean about the roasting process, about the different beans, how to make the best roast for a special blend and how to optimize the taste according to your taste (rather than the taste of an external roaster!). I thought it might be a good idea, especially as I was so tired of the available roasted coffee beans, especially here in Cambridge it seems to be even a bit harder to find fresh roasted good beans.

My first roast was great, although it’s hard to hear the 1st and 2nd crack, probably I am simply not used to it. But the good thing about my coffee roaster (Gene Cafe CBR101) is that you can observe the whole process throughout the glas cylinder. BTW: I do like the roaster. Rock solid and perfect simple but functional design. It is worth the money and it will amortise anyway, as green beans are about half the price of roasted ones.

Now, I simply can’t wait to taste the beans!

Some links you might be interested:
The best home roasting resource around: http://www.sweetmarias.com
The best green beans shop in Europe: http://www.hasbean.co.uk

Amendment statement after 5 roasts (30.5.2006):
The best decision I’ve done on my way to espresso nirvana *hehe*. The pressure thing of Silvia was absolutely inevitable, the PID is helpful and the home roaster just supplies you with good fresh roasted coffee. The difference I experienced in taste between fresh roasted beans and some you buy e.g. from an Internet roaster is immense! In terms of taste I think it is much more worth than e.g. an upgrade to a dual boiler machine or other things you might consider. Try and get a roaster, or ask a friend of yours to roast the coffee and taste the difference!

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