Cold brew is a big deal across much of the English-speaking coffee world. But in the UK, it’s never caught on. However with rising temperatures we think that’s set to change very soon.
A sunny day in the city, all short sleeves and sunglasses and sitting outside watching the world go by. For once, it’s not the gleaming pair of Speedsters in MacIntyre Coffee, sitting low in the bar that draw our attention, but the shapely new bottles of Sandow’s cold brew.
The bottle is a beauty – a hip-flask sized vessel you’ll recognise from the spirits aisle, done up with contemporary branding and filled with 200ml of London roasted, brewed and bottled cold brew coffee.
The brew itself, poured over ice, is refreshing and sweet and subtly complex; the perfect companion to a sunny day.
Cold brew is a bona fide big deal in Australia and the US, where Stumptown has a whole roastery dedicated to its manufacture. In the UK, things have been slower to get going, but this year looks like it could be the year cold brew comes in from the cold and makes it big.
Unlike iced coffee, cold brew never comes into contact with hot water. Instead, the grounds are steeped in cold water for around 16 hours to achieve a proper extraction, a process that develops a unique flavour profile.
“When you brew hot coffee, you’re using energy to extract the coffee,” says Paul Whitehead from Alchemy Coffee. “In espresso you use heat and large amounts of pressure, so the process is quick. In a pour over you’re using heat and a bit of gravity. With cold brew you’re using time.”
“Last summer when it was hot, we had the cold brew drippers in Tap,” says Luke Suddards of Sandows. “We just found that we couldn’t keep up with demand. It’s really hard to maintain consistency and keep an eye on things when you’re trying to run a cafe in Soho. So we decided we wanted to be the ones who made it available to everyone at really high quality.”
And so Sandow’s bottled cold brew was born. Nearly one year later, after much experimentation and hard work, the bottles are appearing in coffee shops across the capital with more to come. So what’s the attraction?
“There are different ranges of flavours within coffee, and brewing with a cold brew method extracts a different range of flavours,”, says Suddards. “Generally, we find it gives you a fresher, cleaner, sweeter taste, because brewing cold doesn’t pull out anywhere near as much acidity as when you’re brewing it hot.” That lack of acidity makes cold brew easier on your stomach, and contributes to sweetness because, as Duffie says, “people associate acidity with bitterness.”
There are two methods of brewing cold – drip and immersion. In the drip method, water drops onto a bed of coffee, passing through the grounds then through a filter into a vessel below, at a rate of around one drip per second. This is the method preferred by Alchemy: “We think the coffee from a drip has a little better clarity”, says Paul Whitehead.
The problem with the drip method is that it’s not particularly efficient in bulk, a problem that led them to the Toddy method, a full immersion process, named after the American Toddy cold brew system. To get round any irritating murkiness to the final product, they double filter the resulting brew, having learnt a lot from London’s craft beer brewers.
“A lot of the equipment we use and the filtration stuff we do comes straight from the beer scene”, says Suddards. “We’ve taken a lot of inspiration from how you brew beer to how you make coffee.”
That affinity with the beer scene is likely to lead to the next big thing in cold brew: cold coffee on tap, carbonated cold brew, and Nitro cold brew, where the coffee is kegged, then forced through the line with nitrogen, producing a Guinness-like head.
“When you have cold brew in a keg, the way you get it down the line and out through the tap is by pushing it out with CO2,”says Suddards. “You leave a small gap between the fill level and the top of the keg and fill that with CO2,” says Duffie. “The other thing we can do is carbonation, so instead of just hooking it up on the day, we could put the CO2 in 24 hour early and that would create a sparkling cold brew.”
Cold brew is typically brewed stronger than pour over coffee. Sandow’s recommend a ratio of 80-120g of coarsely ground coffee per litre of water, while Simon Lewthwaite of Caravan at King’s Cross, says their default ratio is between 350 and 370g per three-litre brew. Brewing stronger allows for ice to be added when the coffee is served. And if you can hold off serving a few more hours after the 16-hour brew period, you’ll be rewarded. “Generally the coffee benefits from sitting in the fridge overnight,” says Paul Whitehead. “It seems to develop the flavours somehow, and once it’s served really, really cold it’s delicious.”
With regards to what coffees work best with cold brewing methods, everyone has a different take on it. Alchemy has found success with naturally processed coffees (where the cherry is left intact during the drying process), with Whitehead saying that: “washed coffee can taste incredibly clean on the finish, which is a good thing. But if you’re after quite a bit of depth, complexity and a kind of booziness,
we’ve had a lot of success with natural processed coffees.”
Sandow’s on the other hand prefer a washed coffee (where the cherry is removed before drying). “The natural thing could be interesting later down the track, but our whole mission is to be the iconic British cold brew, so for the time being we’re just trying to brew really clean coffees. For now we’re using mostly fully washed”, says Suddards.
Continuing the beer theme though, don’t be surprised to see some special-edition brews from Sandow’s, especially on their pop-up bar situated on the South Bank this summer.
If you’re interested in making cold brew at home, Sandow’s recommends looking out for fresh-crop Kenyans, while Paul Whitehead recommends Alchemy’s current Ethiopian Suke Quto, saying, “it’s a washed process but it’s got all the fruitiness and character that can make a successful cold brew.”
Simon Lewthwaite, on the other hand, says that Caravan is currently using a Guatamalan coffee, and “I think we’ll be moving onto another Central American for our next cold brew batch.”
Cold brew equipment needn’t be expensive – a Toddy system for home use can cost under £50 from places like CoffeeHit – but the chances are you could make a passable brew using just the equipment you already own.
Caffeine took everything we learnt from Sandow’s, Alchemy and Caravan and brewed 80g of Caravan’s Kenyan Kikai AB (ground to our grinder’s coarsest setting) with 900ml of Tesco Ashbeck Spring water in a cafetiere and left it to steep for
16 hours in a cool, dark room.
We plunged the cafetiere as a first filtration, then passed the remaining brew through a wet V60 as a second filtration. The result was bottled and refrigerated for a few hours before tasting, and while it wasn’t as good as any of those we tasted from the professionals, as a first attempt, it was sufficiently interesting for us to want to try again.
Cold brew is undoubtedly a great drink on a hot summer’s day, but more than that, it’s a distinctly different drink to hot, brewed coffee – one that shows many coffees in a completely new light. If you haven’t tried it yet, make sure you do this summer, over ice. And if you want one last tip, try it though a straw. You’ll like it.
This article first appeared in Caffeine Magazine in June 2014 - Sandows is no longer trading - Images by Gary Smith