Food & Drink

How to make the perfect iced coffee

Because who wants a hot coffee in this heat?

The Italians might be happy to knock back short shots of espresso in soaring heat, but you needn’t be so hardcore. Cold brew and iced coffee are both much more palatable hot weather options. Don’t just tip ice into your Nespresso – chilled coffee is an art.

Here comes the science

There’s more than one way to brew coffee – drip, filter, plunge, espresso – and each has its merits, bringing out different qualities from the beans. Heat and pressure produce thick syrupy espresso swiftly, often with more bitterness. Reduce the pressure – with a pour-over method like filter or a cafetière – and the process slows, minimising the bitter notes. Reduce the temperature and you slow it down even further. The flavour you want determines the method you’ll use.

The perfect blend

Central American coffees have more chocolatey notes, African coffees are fruitier, and Vietnamese coffee uses Robusta beans for strong flavour, which are then roasted with sugar, caramel and cocoa. Whichever you choose, get beans in season and reasonably fresh. A quick espresso requires a fine grind, but a slower cool brew needs something a little coarser.

Take your time

Where an espresso can take 30 seconds to make, good cold brew coffee can take anywhere between 12 and 24 hours. ‘You extract the same amount of caffeine,’ explains Hugh Duffie, co-founder of Sandows cold brew coffee, ‘but it takes longer. The relationship between pressure, heat and brew is logarithmic. We do 16 hours, and the result is smoother and less bitter. It’s a gentle method.’

Iced iced coffee

Don’t be fooled into thinking you can just make an espresso, let it go cold and then pour ice over it. According to Rob Athill, founder of Cà Phê VN, this will make your iced coffee so weak it’s pointless. ‘Where Starbucks might use around six grams of coffee per shot, we’ll use 20 to 25 grams. Serve it as a couple of inches of coffee at the bottom of a long glass then fill it with crushed ice. As you drink it, you’re stirring it up with the straw to dilute it, which makes it a nice long drink.

One lump or two?

According to the baristas at OPSO in Marylebone, if you like your coffee a little bit sweet, you’ve got to add the sugar early to make sure it’s completely mixed in. They froth their coffee to give it foam, regardless of whether it’s black or white.

Au lait, au lait, au lait, au lait

Cold brew doesn’t have the bitterness hot black coffee does, and is best drunk black over ice. But if you do add milk, Duffie recommends reversing the proportions of a latte, making it one part milk to three parts coffee. Vietnamese-style iced milk coffee, or Cà Phê Sua Da, uses condensed milk. ‘In the UK we like our coffee less sweet and more milky than they take it in Vietnam,’ says Duffie, who recommends cutting the condensed milk with a bit of semi-skimmed for a lighter coloured drink. Serve it on crushed ice, and take your time.

Or, if you can’t be bothered to make your own…


Potent, but with the best foam, this modern Greek restaurant in Marylebone makes one of the best iced coffees in town.

Saigon Street Cafe

Arguably the first to bring Vietnamese-style iced coffee to the UK, Saigon Street Cafe’s a regular on Broadway Market.

Cold brew in a box

If you mainline coffee, keep a three-litre cold brew bag in a box in your fridge and serve yourself at will.