There has long been discussion about what happens when you brew espresso somewhere at relatively high altitude (above 2600 meters).
According to James Hoffmann's blog and post from 2011, at an altitude of above 2650 meters, water will boil at a slightly lower temperature of 91.2°C, below the level of 93.5°C that is generally acceptable in barista circles.
According to Hoffman, when brewing espresso at high altitude the system is under increased pressure (9 bars mostly), much greater than the normal pressure produced at sea level.
One of the unique aspects of brewing under pressure is that water is able to dissolve a lot more CO2 than it usually can at atmospheric pressure. When the coffee liquid leaves the basket it is therefore unable to retain that CO2 which forms the bubbles that contribute to what we all know as the white fluffy surface on top of the coffee or 'crema'.
If you have experienced altitude coffee, it's often commented that the coffee appears as though it hasn’t had a chance to rest or degas. The espresso tends to have very large bubbles, and often lacks strength.
Although a number of us are die hard coffee fans, when it comes to scrutinising the characteristics of what we brew, our satisfaction is reached usually by colour, aroma and taste.
Nonetheless we were pleased to have served over 800 espressos to the participants of this years Alpenbrevet, Switzerland's toughest and most iconic Gran Fondo on offer. Our coffee was well received and filled the Service Corse Cafe with an aroma of urban familiarity.
On a day that can only be described as stunning, the custodians of cycling weather, had well and truly done their bit to provide a backdrop perfect for the 2500 participants, that incidentally sold out in record time.
A sky full of blue and still conditions made the first climb up and over the Grimselpass at 2164 meters almost mythical. The first riders arriving at the summit just on 08.00am.
The scent of coffee was in the air and small crowds had gathered signalling cow bells and shouting roadside cheers as the first and fast chilly descent awaited.
Apart from the stunning roads and climbs on offer to all riders who take on the Alpnebrevet, logistically the event runs to Swiss precision. From the bottom of the first descent, riders begin to splinter off depending on the course selection. The Silver Tour of 132km featuring 3 climbs continues up and over the Furkapass which hits an altitude of 2429 meters. The Gold and Platinum riders take a slightly southern turn towards the Italian speaking region of Ticino as they head up an equally challenging second climb of the Nufenenpass at 2478 Meters.
With riders disappearing down the first descent throughout the morning, the Service Corse Cafe moved across to the Sustenpass which serves as the 'uniter' and final climb of the day for all riders irrespective of course chosen.
At 2224 meters and with the midday sun starting to warm things up, the cafe was pumping and provided respite for many riders throughout the afternoon. As the late August sunshine continued to bounce off perfect roads, temperatures of 30 plus celsius added to the challenge and complexity of taming what on paper should be a straight forward climb.
For many participants of the Alpenbrevet and local riders in the region, the Sustenpass has a remarkable ability to consistently make you suffer. Partly due to the fact that you can see this climb layed out before you from a number of vantage points. Long stretches of 4 - 5 km segments with a gradient averaging 7% somehow creep into your head.
For those riders who take on the Gold Tour, it's a stark contrast to the beautifully meandering 5km cobbled climb of the Tremola, representing hairpin heaven with recovery points at every bend.
With perfect conditions, impressive ride times across all 3 courses and faultless organisation, we could not think of a better place to bring out Spartabus (our 1966 Volkswagon Bus) and serve our best coffee...with crema to a much appreciative bunch of Gran Fondo riders.
Until next year...it's Your Ride!
Words: Carlyle Ware
Images: Rahel Bieri