The trend: Filter coffee

Ever since the first British coffeehouses opened in the 17th century, coffee society has been subject to changing fashions. The espresso bar boom in the 1950s, led by Soho’s Moka Bar and its newfangled Gaggia espresso machine, gave way to the rise of the cappuccino and the slew of coffee chains in the 1990s. And then came the recent craze for flat whites, exemplified by Australian-owned coffee bars in London such as Kaffeine on Great Titchfield Street, and adopted everywhere from Pret A Manger to Costa Coffee.

But now an unlikely fad is making its presence felt, with the cognoscenti extolling the humble cup of filter coffee. Jeremy Torz, co-founder of artisan coffee roasting company Union Hand-Roasted, has no doubt about its virtues. “Filter coffee offers a longer, purer expression of the coffee. It can be delicate, aromatic and smooth, as well as intense,” he says. “People always say they love strong coffee, but actually drink very milky coffee. What a black filter coffee offers is a chance to really appreciate the subtle flavours.”

Invented in Germany in 1908 by Melitta Bentz, who came up with the idea using a piece of her son’s blotting paper to strain coffee, filter coffee took off as a quick, simple way to prepare a dose of caffeine. Embraced by the catering industry as a cheap alternative to the espresso, its reputation has suffered because of the notoriously weak filter coffee made commercially and the bitter stuff left to stew for hours on hot plates.

Nowadays, however, well-made filter coffee has its champions. Respected coffee shops and cafés, including Monmouth Coffee Company and Taylor St Baristas, offer single-origin filter coffee in addition to espressos and cappuccinos, while Starbucks will soon be offering “slow drip” coffee. “We serve filter coffee at all our stores,” explains AJ Kinnell, coffee buyer for Monmouth Coffee Company. “We have done ever since we first opened, so that people could taste the coffee and select which beans they wanted to buy.”

Like Torz, Kinnell attributes filter coffee’s superiority to its clearly defined flavours. “The advantage is that it’s the least disruptive brewing method: what you have is a lot of clarity in the cup. When you make an espresso the process intensifies the flavour of the coffee; it’s like turning up an amp. You can taste the nuances of the flavours so clearly with filter coffee.”

So, how do you make it correctly? At the new Taylor St Baristas café in Mayfair, simply decorated with white walls and a dark wooden bar, I met Torz and Andrew Tolley, who, with his brother and sister, co-founded Taylor St Baristas. “You need a certain amount of diligence to make a good cup of filter coffee,” Tolley says, as the pair explain their methods. First, use the right coffee-to-water ratio (7g-9g to 100ml). Second, the coffee must be freshly roasted (two to 21 days old) and freshly ground (“If it was ground an hour ago, you might as well not bother,” says Tolley). Last, the water should be freshly drawn and filtered to remove any chlorine taint.

While espresso addicts have their gleaming machines, filter coffee fans, too, have their gear. Torz had assembled a range of kit to test, from the Clever Dripper – a lidded filter coffee maker complete with an ingenious shut-off valve – to the Technivorm automatic filter coffee maker. But we started with the basic ceramic filter cone, using a batch of Union’s Rwandan Cup of Excellence Kopakama. (“This has vibrancy, sweetness and a silky mouthfeel,” says Torz.)

First Tolley rinses the filter paper with hot water “to wash out the starch”, then adds coffee, very finely ground to slow down the water’s passage. A little hot water (92-96°C) is poured on to the coffee grounds for what is known as the “pre-wet” – “the idea is to saturate the grounds so that they give out flavour evenly”. He then pours hot water in a fine, constant stream over the grounds for two minutes. The coffee drips through, with the cup whisked away before the last overly bitter drops fall in. No milk is added – both Tolley and Torz drink their filter coffee black, to taste the full complement of flavours.

Next we try the Aeropress, a large, clear plastic syringe that “gives a stronger, more concentrated brew than the drip filter”. The liquid coffee is pressed through the filter resulting in a “stronger, more concentrated brew than the drip filter”. All the filter coffees we sample have depth of flavour without bitterness and a noticeable brightness. “This is what we’re looking for when we make coffee,” says Tolley. “People think acidity is negative but it’s what we want,” agrees Torz. “It’s not bitterness; it’s a brightness or citrus note that good coffee has.”

We finish with a gloriously Heath Robinson piece of kit – the Syphon, which comprises two glass flasks and a burner. A leaping flame heats up water in the lower flask, with the steam pressure forcing it up into the top flask where the coffee is mixed in. After one minute, the flame is removed and, as it cools, the coffee drips down through a filter into the flask below.

The spectacle is so entertaining that there are grins all around. “This is the one to impress your friends at a dinner party,” comments Torz. Those who thought filter coffee was boring need to think again.