How To Make The Perfect Flat White - The Coffee Beverage That Charmed London And Is About To Take New York By Storm

The flat white - an espresso-based beverage prepared with steamed milk - has for a long time been as ubiquitous as sourdough bread and vintage cocktails on the cosmopolitan streets of London and Melbourne.

In wider Europe, Australia, and New Zealand, it has been providing a more refined and delicate option for many others who want to enjoy coffee that has got a milky hit, without the excess that comes in a cappuccino or latte.

It is a winning method.

Now, the flat white is infiltrating the US market. It started catching on in New York City this year, served at coffee houses like Culture Espresso on 38th Street and Little Collins in Midtown, according to the New York Post. Previously, the coffee concoction proved hard to find in North America.

In the UK, the drink went mainstream in 2010, when Starbucks added it to the menu. Others followed, however, and the chain was soon outflanked by rival coffee shop Costa - doing wonders, says the Guardian, for the company's sales given the drink's popularity with coffee "aficionados."

For many, however, the flat white remains a specialist drink - a choice for the hipsters of independent cafes and pop-up bars manned by gurus of the caffeinated game.

There are plenty who order it, but do not really know what it is exactly. And be warned, because it's not simply a cafe latte with slightly less milk, which to many is a statement that amounts to blasphemy; a mistake too readily made.

Artisan coffee shop and training school's Alessandro Bonuzzi agrees: "I still find that the consumer doesn't quite understand the distinction between a latte and flat white."

Business Insider UK spoke to two more experts to clarify the process.

"The key is the milk steaming stage," explains Scott Bentley, who runs Caffeine Magazine. "The milk needs to be steamed to increase the volume by about 25% - this must be done in a specific way to not split the milk and so the milk is a similar texture throughout, like that of paint.

"The old style cappuccino you'd get from a chain cafe would overheat the milk and split it into very airy foam and hot milk at the bottom.

The secret, says Bentley, is "microfoam" - the small, fine, velvety bubbles extracted from coffee pitchers by only knowledgeable hands. It uses free-poured milk so the foam is folded through the whole drink. There's no distinct layer between coffee and foam.

Bentley continues: "The microfoam needed for a flat white is produced by introducing the steam so it swirls the milk in the pitcher and getting the milk hot but not scalding, which is why people sometimes complain that speciality coffee is never hot enough.

"This temperature is also important as it's when the sugars begin to be released making the milk sweeter - again a reason why you shouldn't need sugar in your quality coffee as the coffee isn't bitter and the milk is sweeter."

London's St Clements Cafe has seen flat white sales soar. The cafe's Olivia Grant says it's as much about "ratio" as method. Also essential is a 160 milliliter cup, she says.

She explains: "The milk should be textured but not too foamy, hot but not too hot. It's for true coffee lovers. If poured properly the milk will be put in centrally so the coffee sits at the rim.

"Lately, sales of flat whites here have almost exceeded cafe latte sales."

With its roots in New Zealand and Australia (there's an argument about which nation truly invented it), a rosetta or fern is often put on a flat white to illustrate the Kiwi flag.