Article by Wayne Kwok
The weather’s been unpredictable, but we’re starting to get some hot days. I’m feeling more frequent cravings for iced coffee. Cold brewing (or cold extraction) produces a rich concentrate that’s a great ingredient in iced coffee drinks.
Cold brew produces a smoother cup with less bitterness, astringency , and sharpness. It extracts lower levels of acids, caffeine, and oils which makes it less jolt-inducing and easier on stomachs. I agree with the many critics that cold extraction has its faults. Still, I like it for two reasons: It makes a coffee strong enough to hold up to lots of ice and milk; and, I find it the most forgiving extraction method when using older beans.
It’s not just for iced drinks. Add some hot water for a finer cup of instant coffee. Compared to coffee crystals, you’re starting with much higher quality beans and you’re not losing volatile aromas to the process of making instant coffee.
You might be surprised that making instant with cold brew concentrate can be just as quick in the morning and taste better than pod coffee.
This is my adaptation of Dan Souza’s cold brew method. Dan uses a French press, but I prefer a jar and a coffee sock. A French press makes the straining process easy. A sock strainer is better for squeezing more liquid out of the saturated grounds after brewing. I encourage you to tweak and experiment with the recipe to suit your taste. Share your results!
1. Choosing your coffee
Start with a medium roast. Medium roast beans allow you to taste more of the unique characteristics of the coffee and less of the burnt flavour from the roasting process.
For great coffee, use a water filtration system that removes chlorine and contaminants, but not all the mineral content. Leaving some minerals in the water will give coffee more body and a richer taste.
Coffee starts losing precious aromas within seconds of grinding. It’s best to grind immediately before brewing. Most cold extraction recipes will call for a coarse grind. Use a fine grind to get the most flavour from your beans. Don’t worry about over-extracting when using room temperature water. The downside? Finer grounds are harder to strain out after brewing.
Use 1 part coffee and 4 parts water by weight. 1 mL of room temperature water weighs approximately 1 gram. Even though the exact ratio varies with the temperature of the water and your elevation, a scale keeps dosing consistent. It’s hard to be consistent when measuring by volume. Coarser grounds will take up more space than finer ones. The volume also varies by how compacted the grounds are. If you don’t have a scale, start with 1:1 by volume.
Stir room temperature water into the ground coffee. Make sure all the grounds get saturated. Wait ten minutes and give the slurry a few more stirs.
Cover the container with plastic wrap and leave it at room temperature for 24 hours.
Push down the plunger on the French press to strain. If you used a jar, strain through a coffee sock or fine cloth strainer.
8. Filter (optional)
For a cleaner cup, strain again through a paper coffee filter. Depending on your grind size, you may need a spatula to help unclog the bottom part of your filter.
The concentrate will keep well in the fridge for two weeks.
Making Iced Coffee
Once you have your concentrate, dilute it with water, milk, or combination of the two. Add ice. Start with 1 part concentrate to 2 parts milk/water and adjust to taste. Depending on your coffee beans and grind, you may be able to dilute it as much as 1:4.
Dan Souza suggests that sugar is unnecessary in a super-smooth cold brew. He recommends stirring in a pinch of kosher salt instead. Sounds foreign, but a little salt will enhance the flavour. Other variations include adding a quarter slice of lemon to your black cold brew or mixing with coconut water. Go crazy!
Making Instant Hot Coffee
When you’re rushing to get out the door in the morning, you’ll be thankful you have the concentrate on hand and not have to settle for the crystals. Use water that’s a few degrees from boiling. You can turn on the kettle and come back to it later. Start with 1 part concentrate and 4 parts hot water and adjust to taste.