Hi-tech coffee: What's the buzz?

From computerised percolators to ergonomic espresso-machines, making coffee has become a hi-tech affair. Rob Sharp reports from the cutting edge of caffeine

To the untrained eye, the PC base unit belonging to Tim Quax, a computer programmer based in the Netherlands, looks like any other electric-green metal shell with huge black flames licking its sides. But inside the garish carapace of Quax's Compaq Deskpro lies neither motherboard nor disk drive. Instead, it contains a chamber for boiling water, a filter, a plastic nozzle and a place to store finely-ground Arabica beans. According to the machine's maker – who has melded the external parts of a computer with the functioning innards of a coffee machine – this is neither PC nor beverage generator. "It is a coffee-maker integration project," he says.

Among the countless millions of who enjoy a hot cup of coffee in the morning there is a breed apart. These are the caffeine freaks who want to harness technology to make their brew even better, whether it is home-grown aficionados like Quax – who've now taken to modifying their hardware, and posting the results on specialist "modding" websites like ByteMods.com – those posting on coffee blogs like the US-based Coffeegeek.com, or head honchos at international coffee companies and thirsty thinkers seeking the ideal cup of joe.

The latest piece of hi-tech kit providing a buzz Among these obsessives is the Slayer. Since it was launched last summer in the US the £12,000-a-piece machine has been sold to 20 coffee shops scattered close to the Seattle-based company that makes it; there are now plans to launch the machine in Britain. Its appearance has given coffee-lovers the jitters. With its rustic design and cutting-edge technology, it gives baristas a never-before-seen amount of control over how they pull an espresso shot. "The design alone is mesmerising," writes Erin Hulbert, a blogger on US food website Seriouseats.com. "The ergonomics provide smooth movements much easier for your body to withstand. The short height of the machine allows ample visibility for the barista and client to connect, creating better relationships."

According to bloggers such as Hulbert, the Slayer is part of the latest evolutionary waypoint in coffee consumption, something known colloquially as "third-wave coffee". Third wave, goes the theory, involves the rise of independent coffee shops – in London, there is the boutique coffee house London's Taylor Street Baristas, for example – which source a relatively small number of beans from small-scale farms. Starbucks – by dint of its size – is often unable to deliver this.

"What we're doing is a complete departure from the kind of coffee conventionally sold in bigger chains," says Eric Perkunder, one of the Slayer's designers. "Coffee has always been looked at as this monolithic property, bought in bulk. Nowadays the sourcing of beans is viewed much more in the way wine is. People source them from specific farms; often you can get a certain taste from a specific place. In order to make use of that specificity a new breed of machines has had to emerge."

By definition, espresso – which involves forcing boiling water through finely-ground beans at a pressure of around nine bars and a temperature just below boiling – employs the most complex technology. Its evolution began with a piston-powered machine invented in 1945 by Italian entrepreneur Achille Gaggia, still seen in traditional coffee shops, where the barista forces the water through the coffee with a lever. These days the process is more likely to be driven by steam or electric pump. Steam-powered machines often double-up by providing a facility to froth milk for cappuccinos.

The most cutting-edge commercial machines – along with the Slayer, there are the Seattle firm Synesso's Hydra, and Italian espresso manufacturer La Marzocco's Paddle – employ a process known as "pre-infusion". This sees the barista saturating the coffee at low pressure before hot water is pumped through at a higher, espresso-necessary pressure; it mitigates against "channelling" in which water unevenly passes through dry coffee grounds, resulting in certain parts of the coffee being exposed to too much water, and affecting the taste. La Marzocco's next machine, Strada, a prototype of which was unveiled in September, contains electronics that record the pressure employed by the barista at different points during an espresso's production to create a specific "profile". The attendant will then have the option to replay these profiles when making subsequent cups.

Meanwhile, the £7,000 Clover is revolutionising the market for filter coffee. Launched in 2006, the machine created such a buzz that in March 2008 Starbucks bought its manufacturer, the Coffee Equipment Company. Hand assembled, the Clover fully automates the process of mixing coffee grounds with water. It works as follows: the user adds their coffee to a chamber on the top of the machine. A tap automatically adds boiling water. After the coffee has steeped, a piston raises a mesh-screen platform within the chamber, now carrying the used coffee grounds. A vacuum is created beneath the platform which draws the coffee through the screen. The vacuum is destroyed by the opening of a valve; this causes the coffee to flow through pipes and out of a tap at the bottom. The process ends with the platform raised, allowing the spent coffee grounds to be disposed of. The barista can control brewing time, temperature and the amount of water added to the mix; the machine's electronics allow the user to save combinations. "The Clover has become a fetish object among the coffee-obsessed," writes technology journalist Mathew Honan in US Wired, after Starbucks acquired its maker. "Long queues signal its arrival in new cities, and self-described 'Cloveristas' post videos on YouTube demonstrating the machine's flashy brewing process."

While the hi-tech equipment behind the Clover is yet to filter through to the domestic market, home brew buffs have a host of other options. If you're talking about a classic cup of filter coffee, most operate on the simple premise of dripping boiling water through coffee and employing a filter. The espresso experience is harder to replicate. The Bosch Tassimo, at £160, employs "flash heater" technology – where water is heated as it is needed, rather than a tank being warmed up – meaning hot water is almost instantly accessible. Users insert different coffee cartridges with different barcodes that the machine's electronics recognise. Instead of water being forced through at pressure, it is pushed through the cartridges at speed; this produces gas, which replicates the "crema" – a thin layer of foam – of commercial espressos.

Then there's the Gaggia L'Amante, at £300, which also uses a capsule system that helps keep the coffee fresh – and avoids the process of tamping, where the barista will compact the coffee before it is put in the commercial machine. At the high end, machines retail at around £700 – features include water hardness settings and a multi-lingual display. Siemens has collaborated with Porsche to deliver Nespresso coffee, the capsule system owned by Nestlé and boasting revenues of up to £500m annually. Essentially, though, all these capsule systems operate in similar ways, employing pre-packaged blends of coffee which are subjected to a variety of temperatures and pressures.

The purists maintain that unless you are sourcing from small farms and grinding, tamping and pulling the shot in the right environment, the coffee just isn't really the same. "I've got a Gaggia, which gives you a good result, you get a decent crema and the taste is pretty authentic," says John Sherwood, chairman of the British Barista Championship (the London heats of the World Barista Championship, for which he is a judge, are being held this week). "The water heating is pretty instantaneous. As technology goes forward the quality gets just gets better. It's my opinion, though, no home machine will ever perform as well as the ones in shops. They just don't have the power."

In order to more closely replicate the coffee-shop experience, some users have taken to modifying their home machines. One way of doing this is by fitting a PID – a proportional-integral-derivative controller, if you will – which helps maintain consistent espresso-quality temperatures. Be warned – they will invalidate your warranty and involve complex wiring to replace your thermostat (to find out more, just Google "PID" and "coffee machine"). Putting coffee-makers into PC shells is also popular. As well as Quax, the US modding website tomshardware.com shows off the efforts of another modder who spent almost £2,000 on components.

"I used to work full time with computers," says Quax. "Since automation is key, I used my experience to automate what I like best; coffee. I built the computer that makes coffee, which is controlled completely by computer software. Though you still have to walk, type, etc, the second version automated those obstacles as well; the full automatic coffee maker. It makes coffee every morning and brings the mug to my bed using a rail." So why does he do it? Surely it's not entirely healthy obsessing over the perfect cup of something that in large doses can feed anxiety and keep you awake at night? "I simply love it," he explains. "I love tweaking electronics, computers, software, to do what I want them to do. From there to coffee mods is just a small step for a coffee addict."