5 Things You Need To Know About Cold-Brew Coffee This Summer

TORONTO - As the dog days of summer scorch on, no one wants to swelter through a hot cup of coffee, but most people still need their daily caffeine kick. At the same time, many coffee shops charge premiums for the privilege of simply watering down your hot coffee with ice.

The answer, though, is within reach: cold-brew coffee, a style that has enjoyed a recent resurgence for its natural sweetness, its lack of acidity and its simplicity.

While a hot cup of coffee will have a stronger aroma and flavour, heat also brings out the bitter flavours of a bean. Cold-brewing takes out those stomach-churning bitter acids and will allow the subtler, more floral flavours to bloom, producing an extremely smooth, drinkable coffee with all the energizing kick of a piping cup of joe.

In Toronto, the Rooster Coffee House is starting up a summer cold-brew station at its King Street location. Manager Kyle Wilson, who will compete this year in the intense Canadian Brewers Cup, has offered tips and tricks so you can beat the heat and satisfy your caffeine needs at the same time.

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1. Understand the basics

Cold-brew coffee gets its name because, rather than using hot water to extract the coffee grinds from a vessel like a French press, it involves a slow infusion in cold water over the course of 12 to 20 hours. "It's great to make the night before so it's ready for when you leave for work," says Wilson.

It's simple enough: start with a French press, fresh cold water, coffee beans and ice. Grind the coffee somewhat finely — about the consistency of gritty sand — and dump it into the French press. Using a ratio of one part coffee and five parts water, pour cold water into the French press. Place plastic wrap or a tight-fitting lid on top of your French press and leave it on the counter for at least 12 hours, and as long as 24 hours.

"It's really low temperatures, especially if you refrigerate it, so you won't be extracting much (if it's much less than 12 hours)," says Wilson.

Once the time has elapsed, filter the grounds by pressing down the plunger, then pour the liquid through a coffee filter or cheesecloth to get rid of any remaining residue. This is your coffee concentrate, and you should use an equal amount of concentrate and water for each serving. Add ice, and enjoy.

If kept properly in your fridge in an airtight container like a firmly closed mason jar, you can keep your coffee concentrate for as long as two weeks.

2. Weights and measures

The variance in the quality of your cold-brew will often come from the beans, your fastidiousness to the process and the equipment you use, Wilson says.

Wilson compares it to baking, with its specific times, weights and measurements, to achieve a consistent and delicious product every time.

He weighs the ground beans and recommends one part ground coffee to five parts water as a good baseline. (Use a scale or measuring spoon and glass measure and aim for about 10 grams/two tablespoons of ground coffee to 50 millilitres/1/4 cup of water.)

"If you are weighing it out properly, if you like something, you can replicate that, and you don't have to guess once again to make it again."

3. On the grind

The grind of the bean is also crucial. Wilson says if you don't have a burr or hand grinder, the best option is to ask your local coffee shop to grind it for you.

"You need a consistency of grind to translate over to taste. If some is coarse and some is fine, you'll get this unbalanced taste," he says. "You're left with something that's not as good as it can be."

He says he likes to buy his beans locally, and that he rarely drinks a dark roast coffee.

"People spend a lot of time developing a roast profile to bring out the most flavour of that coffee bean, and when you go too dark, you lose all that, you get into overcaramelizing, burning your coffee — you sacrifice a lot of flavour to get that bitter taste."

4. Try an advanced technique

While producing cold-brew can be as easy as pouring cold water into a French press and letting the ground beans sit and steep for at least 12 hours, Wilson swears by a slightly more advanced technique: using hot water quickly, and then finishing with cold. This will allow, for a brief time, some of the gases to escape the beans, which will bring out fruitier flavours.

"When you're making cold-brew, you don't get the acidity. This way you get some of that brightness, some of the acidity that would be lost."

For this method, you will use the same ratio of coffee and water described in the basic method above. Divide the amount of coffee you will use in half. Mix half in the French press with about the same amount of very hot water and stir for about 30 seconds. Then add the remaining ground coffee. Top with the remaining water (it should be cold). Continue as you would while using the basic method — wait between 12 and 20 hours for the coffee to steep, then add water to your coffee concentrate.

5. Be creative and have fun

Wilson honed his coffee wisdom by spending years working in the restaurant industry in Australia, where he says the culture is deeply imbued with the crema of an espresso. And so he adds that while some of these tips seem arcane and complicated, it's important to simply love what you're doing and try what works best for you.

"There are rules to follow, but sometimes not following the rules, you can get creative and stumble on something that may not be out there," he says.

The less water you add, he says, the stronger your brew will be; he also says that while he's settled on 20 hours as the ideal brew time, he's never tried doing it for longer — and says you should feel free to do so. And for those who like it hot: simply add as much hot water as concentrate you use, and your sweet, floral cold-brew is a hot, unique-tasting cup.

There are many types of equipment available on the market, all producing a different quality of brew: from the buxom leather-wrapped Chemex, the smooth single-serve AeroPress, and the cold-brew-specific filter system Toddy.