When it comes to plunger coffee, everyone knows best. If you’ve ever been dive-tackled as you go to plunge the coffee, or had a spoon wrestled from your grip mid-stir, then you’ll know what I’m talking about. I’m a big fan of plunger coffee, but it has certainly tested more than a few relationships over the years.
Which is why I decide to spend an hour studying the secret art of plunger coffee with someone I’d never dare argue with – Peoples roaster and human encyclopedia of coffee, Rene.
He begins by introducing me to the holy trinity of plunger coffee: grind size, brew ratio and water temperature. While every step of the process is important, varying these three factors will affect the taste of your coffee more than anything else.
So let’s start with grind size: Coffee should be ground much coarser for a plunger than for an espresso machine, to a gritty sand-like consistency. And it goes without saying that you should grind your beans fresh each time.
“Coffee degrades when exposed to oxygen, so you should use it within about a minute of grinding.”
Water temperature is also key. You shouldn’t use boiling water straight on ground coffee, as it produces bitter and sour flavours. To cool the water down, either let the kettle sit for three minutes after boiling, or pour it into another vessel before pouring it into your plunger. (I know, waiting is not my strong point either. But trust me, the coffee will thank you).
Once you’re ready to pour, half-fill the plunger and give it a good stir (but not for more than ten seconds, says Rene). “By stirring it you’re activating more infusion and encouraging that extraction of flavour.”
Let it sit for a moment, then pour the rest of your water in and leave it to brew for another three minutes before serving.
Now for the big one: brew ratio.
I’ve spent the last five years heaping coffee into a plunger like the world was about to end. But this is one of those times where less is more.
To prove the point, Rene makes two plungers, one with 18g of coffee and one with 20g (to 300mL of water). And although it’s only a matter of grams, the contrast between the two brews reaches up and slaps me in the face. The 18g brew is much lighter and fruitier. The 20g brew has a stronger coffee taste, and while delicious, it‘s definitely missing the more subtle flavours of the first cup.
“The golden rule is one part coffee to sixteen or seventeen parts water,” Rene tells me. But how is the average person supposed to figure that out? Simple. You use scales and a calculator.
“It’s geeky, but if you want to have a perfect cup every day, you’ve got to use them,” says Rene. “I’d like to arm all the people who are passionate about coffee with a set of scales.”
(You can pick up a set at the Constable St store).
Rene is an exceptional sort of coffee geek, so if you’re not quite there yet, then he recommends you at least weigh it once to see what it looks like in a measuring spoon. Then measure the water into the plunger and see where the level rises to. From then on, you should stick to those measures like your life depends on it.
“It’s important to do the same thing every time, unless you’re experimenting. If you’re not aware of what you’re changing, you’ll never be able to replicate a good cup.”
So there you have it. Plunger coffee 101. Any arguments, see Rene.
(Or you could leave him a comment, below)
December 14th, 2011