This summer, we've fallen in love with cold brew coffee. Not only is it refreshing on a warm summer day, but the process of brewing coffee using only cold water results in a uniquely smooth and pleasant summer drink.  Propeller Coffee Co, based in Toronto , serves up some of our favourite cold brew in the city. We caught up with owners Geoff Polci and Losel Tethong to get their expert tips on how to prepare the very best cold brew coffee at home.

Canadian Living: How did your passion for coffee come about?
Losel Tethong/Geoff Polci: Geoff's passion for coffee came from years owning and running a restaurant with his wife in Costa Rica. He first founded Toronto's Crema Coffee Co when he returned to Toronto. My passion for coffee and sustainability came about from being one of Crema's earliest customers and fans, which began a near-decade long learning process on what it takes to source, roast and serve great coffee.

CL: How did you start making cold brew?
LT/GP: Crema has been making cold brew in small batches at each of its three locations for years, using a cold water extraction process called Toddy. At Propeller, we've been preparing and serving small batch cold brew in our cafe since last summer.
With huge demand from our wholesale cafe and restaurant customers for a premium cold brewed coffee - we decided this past winter to step up our game and have created our official Propeller Cold brew in 330ml stubbies and nitrogenated in kegs!

CL: What kind of coffee beans would you suggest using when making cold brew?
LT/GP: We suggest using a high quality, high elevation light-to-medium roast with lots of acidity. We find that African coffee works really well when brewed cold and can produce unique flavour profiles compared to a traditional pot of coffee that's brewed using hot water.

CL: How long should you steep coffee when making a batch of cold brew?
LT/GP: Firstly, it's important to grind your coffee on the coarser side - somewhere between a filter grind and a french press grind. If you’re brewing your cold brew in the fridge you should aim to steep the coffee for 48 hours, but you can also brew it at room temperature which will speed up the extraction.
A room temperature brew will be done somewhere between 30 and 36 hours. You can also experiment with brewing at both temperatures: Steep the coffee for 12 hours at room temperature, then move the brew to the fridge for 24 hours.

CL: Does the coffee intensify in flavour the longer it's brewed?
LT/GP: The coffee flavour does intensify the longer you steep it. However, there will be a point where it will start to over-extract. It’s important not to leave the coffee to steep too long. All the nuanced flavours, nice acidity and sweetness will be diminished from over extraction of the coffee so it will take some experimentation to find the optimal steeping time.

CL: What is it about brewing the coffee with cold water that enhances the taste of the final product?
LT/GP: Cold brewing extracts the acids in the coffee differently and pulls out many different flavours. You're commonly be able to detect hints of lemon, lime, orange, chocolate, honey and maple syrup. It also gives a syrupy sweetness to the coffee.

CL: How long will cold brew keep in your fridge?
LT/GP: Homemade cold brew should keep in the fridge for 2-3 weeks.

CL: What ratio of water to ground coffee do you suggest using?
LT/GP: We recommend using 85 grams of coffee per litre of water.

CL: Is there a cold brew machine you suggest using for making cold brew at home?
LT/GP: We're partial to the Toddy Cold Brew system!

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