While the Costa Coffee lab manager doesn't quite hold what's arguably the most expensive tongue in the world — his colleague, coffee-taster Gennaro Pelliccia's tongue is insured for 10 million pounds — Hugo Castaneda possesses an intrinsic chemistry with coffee.

The Colombian grew up working on his grandfather's coffee farm, where he'd learned how to grow coffee, manage the plant and pick out the colours in the coffee. His education and experience in food engineering and chemistry soon landed him in the London-based role as Costa Coffee's laboratory manager — where quite simply, his job's to ensure that all of Costa Coffee's coffee tastes the same. On average, he tastes at least four double espressos a day. Fortunately for him, the effects of caffeine don't really sink in.

Hugo Castaneda
"I don't get shaky, nor do I get headaches or digestive problems — I'm lucky", shares Castaneda over a cup of coffee (what else?) on a wintery London morning. We were en route to the company's roastery in Lambeth, a 15-minute walk from Westminster Bridge in the heart of London. Founded by Italian immigrant brothers Sergio and Bruno Costa in 1971, the brand has since expanded internationally to locations in India, the Middle East and Singapore, where it has eight outlets.

In 2010, Costa Coffee introduced the flat white, complete with an appearance by Aussie singer Peter Andre at the launch. The Australian's answer to the latte, flat whites have taken the world by storm. Made from two short double shots of espresso, hot steamed milk is prepared and poured at an angle to add a velvety smooth micro-foam that tops the brew. It sits smugly in a ceramic cup on the countertops of industrial chic cafes, singling out connoisseurs from poseurs. The flat white presents a silkier, denser alternative to the latte, and someone with a well-groomed beard is most likely to serve it.

But in an industry where specialty coffee shops are a dime a dozen, what makes a good flat white stand out? As Castaneda's subordinate pours us a cup, he points out the qualities to look out for:

Costa Coffee's mocha, flat white and latte


1. Look: Visually, if you see a weak contrast between the colours of the milk and coffee, it indicates a poorly foamed crema. You should be able to see a clear difference between the two.

2. Aroma: Look out for sweet aromas with hints of toast and white chocolate. If you smell something carbonic, it's an indication that the coffee was burnt during production, badly extracted from the machine, or the espresso was left alone for more than 25 seconds.

3. Taste: What makes a bad flat white? When the taste is very wet. This means that the coffee has a lot of liquid milk and wasn't foamed in the right way. A good flat white has to be creamy. It also has to have a bit of sweetness due to the lactose of the milk. Typically made by whole milk, the flat white's creaminess is attained when the fat in the milk is warmed. 

You don't have to look far and wide for a good flat white. Sometimes, the nearest friendly coffee chain might very well surprise you.

To find out where your nearest Costa Coffee outlet is, click here. To read our interview with the author of Costa Book Awards' Book of the Year, click here.