Cold Brew Coffee
It’s Summertime in Australia, perfect weather for gelatos, slushies and iced coffees. The Melburnian Summer, with its sporadic hot days, brings about a change in my morning coffee palate. From my usual homemade piccolos, I find myself occasionally reaching for cooler, lighter alternatives.
I started appreciating cold drips a year ago. The slow ‘cool-brewing’ process somehow stretches the flavour characteristics of the beans ‘sideways’, turning it into a sort of nuanced, tea-like drink with slightly deeper flavours. I find cold drips perfect for mornings following warm nights, or as a refreshing drink to go along with mid-afternoon sweets and pastries. But the science behind making cold drips is complicated, and the equipment to make it, while sexy-looking (tortuous glass tubes, alchemist’s taps, wooden frames), is expensive.
The home alternative is called a cold brew… almost like a ghetto cold ‘drip’. Add water to ground beans, refrigerate, then filter. The end result is still pretty good, not to mention the method’s quite easy! I will share it with you here.
There’s still a bit of science and logic behind making a good cold brew. Special thanks to Lachy, who gave me a few pointers. I’ll share the tips here before placing the (incredibly simple) recipe at the end of the post. Please note that I’m not a barista, so my ‘science’ and recommendations here may not be all that accurate or expert. Still, I have enthusiasm on my side. =)
The most important decisions you have to make with cold brews are:
What beans you use, how coarsely it’s ground, and your brew time.
Ideally, you should use beans roasted for filter coffee. Espresso roasts tend to impart bitter characteristics with cold brews. Filter roasts are roasted lightly, before or just past first crack ~ 205ºC. These lighter beans suit longer cold brew times and allow you to taste the ‘soil and climate’ of where the beans came from. When buying, look out for logos or words on the packet saying ‘filter’, or just ask your barista. The ideal age of beans for making cold brews stands at 10-20 days from roasting date, if you use it too young it tends to taste ‘leafy’.
But if you’re anything like me, you probably can’t justify buying a 250g bag of filter roast beans because that makes 3-4 litres of cold brew, too much! So the alternative would be to still buy espresso roast beans, but from roasters who make lighter roasts. In Melbourne, Market Lane Coffee, Proud Mary and Seven Seeds comes to mind. This way, you can toggle between making cups of espresso, and then a small batch of cold brew for warm days.
Recommended grind size varies between downright chunky pieces used for plunger coffees to the medium gritty texture (like coarse sand) that’s used for filter coffees. Larger coffee particles allow for longer contact time in water. The darker the roast is, the coarser your grind should be. If you don’t own a grinder, you can ask your barista to grind it for you, but please note that the beans lose a lot of fresh volatile compounds within minutes of grinding.
Once you got the beans and grind size organised, the rest is easy. Just add a bit of hot water (ideally coffee machine water at 92-96ºC) to the freshly ground beans and steep it for 30-60 seconds. Then dilute the ‘bloom’ with room temperature water. Cover and place the container in the fridge.
After brew time is completed, run the brew through a coffee filter… it drips quite slowly, so be patient. I didn’t have the right equipment, so what I ended up doing looked very ‘ghetto’ indeed! A more stylish way would be to use V60 drippers (for filter / pour overs), but I’ll only invest in that if I start to enjoy filter coffees more.
You may think the caffeine levels in cold brews and cold drips are less than what’s in espressos. Guess again. An espresso shot has a short contact time of 30 seconds with hot water, while a cold brew has a contact time of 3-24 hours. Caffeine levels can end up being quite similar.
For variety, cold brews can also be served mixed with cola or ginger beer. Also, listen to your taste buds and make adjustments. If the brew is bitter – grind coarser or brew shorter the next time. And vice versa if it ends up tasting ‘thin’.
Cold Brew Coffee
In a clean glass vessel, add:
200ml hot water
to 60-70g of fresh ground coffee (preferably filter roast)
Allow to steep for 30-60s, then add 800ml water. Stir.
Cover, place in fridge for the recommended brewing time (as listed in the table below).
When finished, filter it with a coffee filter.
Keep in fridge, covered. It stays fresh for a week.
Serve with ice.
Brew Time / Grind Size
Ideal: Filter Roast – 18-24hrs / Filter Grind (medium coarse)
Middle Ground: Light Espresso Roast – 6-8hrs / Plunger Grind (coarse)
Less Ideal: Regular/Dark Espresso Roast – 3hrs / Plunger Grind (extra coarse)