Cold coffee has long been associated with huge coffee chains, vats of whipped cream, sweet artificial syrups and other such miseries.
This summer, however, New York City introduced me to cold-brew coffee – a very different, far more refined creature that made me realise the magic of cold coffee, just in time for a warm English summer.
We have it easy here; the crowds and sweat of New York City in the height of summer are no joke. It’s dangerously hot – so much so that long, cold coffee is not so much a component of daily summer routine for New Yorkers as it is a tool for survival.
As it happens, though, my first experience of cold coffee in America was a simple iced coffee – standard filter coffee poured over ice – from a bodega in Bushwick, Brooklyn. It was cheap (a dollar, in fact) and over-bitter, and as I dragged myself through the blistering heat, sipping slowly and grimacing, I cursed it and all those who’d gotten my hopes up about this drink.
The next day, however, I was taken to a nearby café for a breakfast bagel and a “proper” cold coffee. I ordered a warm bagel stuffed with cream cheese and tomatoes and dripping with hot sauce (seriously, man, that bagel) and a black cold-brew coffee, which was served in the same manner as the previous day’s disappointment: over ice in a clear plastic cup, with the end of the paper wrapper covering the protruding end of the straw (as is the style). I sipped, and gasped – it was subtly sweet, rich in flavour but not overwhelming, ice-cold but far from watery, utterly refreshing, and somehow had everything I love about coffee whilst absolutely unlike anything I’d ever tasted.
A chat with the team running the café revealed that cold-brewed coffee is ground coffee steeped in cold water and strained, and iced coffee is generally brewed hot and poured over ice. Elementary.
The difference in flavour between the two methods is immense. Iced coffee is a very fast process, but has to be brewed to be stronger than standard coffee to make up for the severe dilution caused by the ice. This method tends to make for a more bitter drink, because of the intense and rapid extraction of flavour from the beans by the hot water. Cold brew, on the other hand, takes a formidable 18—24 hours. However, the far gentler infusion process produces a drink of lower acidity, which is why cold brew coffee is naturally sweeter. It can also be served over ice without such extreme dilution because it’s already cold. For these reasons, cold brewing is generally regarded as the better method for producing cold coffee.
There are a couple of home-methods for this, and they are all variants of a basic formula: cold water, coarse coffee grounds, and an overnight brew. Changing a variable will produce slightly different results, from a longer brew or stronger coffee-to-water ratio producing a stronger cup, and a finer grind producing a cloudier drink.
There are things you can buy designed for the cold-brew process, such as the monstrous Yama Drip Tower – something you may have seen act as the centrepiece in trendy cafes. Intricate inventions like this, while absolutely delightful to look at in a very Wallace-and-Gromit way, are completely unnecessary for home-brewing (unless you really do have a glut of cash and space). A far more practical tool is the highly regarded Toddy system – the Volvo of cold-brew methods. Like its hot-brew cousin, the AeroPress, the Toddy is ugly as sin, affordable, remarkably simple in process and produces a consistently superb cup of coffee. You can even brew cold in a cafetière (or French press, to our American friends) by following the guide below and simply pressing down with the plunger after the brew is finished – the only negatives being how much you can make at one time and the effectiveness of the steel filter.
That said, you actually needn’t buy anything to brew cold coffee at home, as you probably have everything for a DIY version already: all you really need is a big jar, a big bowl, a sieve, and either a sheet of muslin or a roll of paper towel.
How to cold-brew coffee at home
- Set your grinder to its most coarse setting, and check a little of its output before doing the full grind – you are looking for roughly the same consistency as breadcrumbs. Any finer and you risk cloudy, grimy-tasting coffee.
- Sterilise a large mason jar (or any large receptacle with a lid). Working to roughly a 1:8 coffee-to-water ratio, place your grounds in the bottom of the jar, and cover with cold water.
- Stir gently until well combined, then cover and leave to steep for 18-24 hours, either in or out of the fridge.
- When brewed, strain into a large bowl through a sieve to remove the larger grounds. Discard these (ideally into compost), and then, tucking either your muslin or a few sheets of paper towel into the cleaned sieve, strain back into the jar.
- Repeat two or three times, until you are seeing no murky residue at the bottom as you finish your pour. If you cannot seem to sift it all out, don’t worry – it simply means your grind was too fine. Practice makes perfect with these things.
- Serve over ice, with milk and sugar, if that’s your thing. Cover and refrigerate the rest – the wonderful thing about this stuff is that, if stored properly, it will stay good for a month or so due to the brew’s low acidity.
Brew your cold-brew strong enough and you can even mix it with boiling water and serve it hot. This is a really special way of doing things – the gentle, sweet flavours survive being combined with hot water because there aren’t any grounds left in the mix.