There is an episode of the hit TV series Breaking Bad in which Walter White, high school chemistry teacher turned drug kingpin, meets a new colleague in front of a tangle of clamps, pipes and slowly dripping flasks. When the other character lets him taste what he has been brewing, White is stunned. “My God, that is the best coffee I’ve ever tasted,” he says. “Why the hell are we making meth?”
Coffee may not be – quite – as addictive as methamphetamines, but to some of its aficionados, the hunt for the perfect hit of bean, roast, grind and brew is as seductive as any drug. That search took another step forward this week with new research into the optimal height and speed from which to pour water on to coffee grounds.
The perfect cup of coffee, of course, is as individual a preference as the perfect partner, and if yours is a spoonful of Mellow Birds with a slug of milk and four sugars, by all means you do you. But if we can agree that bad coffee certainly exists – boiled to a bitter sludge on a roadside diner hotplate, perhaps, or tipped into tepid milk by an indifferent barista – it is possible to refine the process to make a better one.
Like a fine wine or artisanal cheese, the process of coffee making has a bewildering number of stages, any one of which can be tweaked to change the taste of the final cup of joe.
First, and to some coffee experts most important, is the bean – its variety, country of origin and even the altitude at which it is grown. Artesan producers often favour the more complex arabica beans, but the cheaper robusta variety, which releases more caffeine, can produce a creamier and more robust drink and is widely used in espresso. Much research is now focused on improving breeds and yields to meet consumer demands.
Then there are the intricacies of the roast – light, medium, medium-dark or dark – which bring out different qualities and are suited to different types of brew. Dark roasts are usually favoured for espresso, but can also be used by mass producers to ensure large scale consistency from a blend of coffees, says Kev Lewis, a coffee roaster, blogger and YouTuber based in Manchester. On the other hand, those seeking a more refined pour-over might prefer a lighter roast.
You can roast coffee at home, but it’s a faff, not least because coffee has to “de-gas” for five-10 days after roasting, says Lewis. What he does consider key is the grind, which is why he says: “If you were to spend £400 on a grinder and £100 on an espresso machine, you’d get way, way better espresso than if you flip that the other way around.”
That’s because beans ground to evenly sized grains rather than smashed to bits by a blade will brew at the same rate and give a more balanced cup. Scientists, needless to say, have worked out the perfect mathematical formula for grind dimension – a coarser grind means more consistent coffee. The wrong grind can “ruin great coffee”, agrees Tom Saxon, who fell in love with coffee while working as a barista in Australia and now runs the UK coffee subscription business Batch. “Whether you’re grinding it too fine and then overextracting the coffee, grinding it too coarse and underextracting it, adding water that’s not the right temperature or putting too much coffee in there,” he says.
How you choose to brew it is up to you – French press (cafetière) or AeroPress, espresso, drip or stovetop – but bear in mind that the composition of the water you use, the speed of infusion and even the time of day you drink it will all change the drinking experience.
On the other hand, you could just walk into any high street chain and order your usual caramel latte. “Some people absolutely love Starbucks,” says Lewis. “Personally, I wouldn’t go and get a coffee in Starbucks, but that’s because I’ve spoiled my taste buds. But good coffee is what you really like.”
How to make the perfect coffee
Coffee, as I quickly realise whenever I talk to an expert on the matter, is a complicated business – sometimes I long for the days when instant was all I knew. So, after having my mini grinder disparaged by a so-called friend (apparently they produce “very uneven results”) I tend to keep the process very simple.
I start with ground coffee (if I’m feeling flush, there’s a lovely independent coffee roastery up the road where they grind the beans to order – at the moment I’m drinking their Brazilian Santos – but if not I go with whatever nutty, chocolatey Fairtrade blend is on offer at the supermarket), eyeballed into the cafetière.
I then boil the kettle, let it stand for a minute to bring the temperature down (this minute can be elastic depending on whether I get distracted in the meantime), pour it on top, stir vigorously with a sundae spoon, then let it sit for four minutes before stirring again and plunging.
Alternatively, for a real punch of caffeine, I use an Italian stove-top moka pot filled with boiling water and slightly more finely ground coffee and then set on the hob until it splutters to life.
Whichever I go for though, I tend to drink it black, so no faffing about with milk pans or frothers for me: straight back to work.
