Like surprise parties and camping trips, cold brew is a planner’s dream. With a bit of foresight and some basic instructions, the Filtron method is the most reliable and delicious way to achieve a single origin iced coffee at home. Set your stopwatch for a 12-hour countdown and you’ll be generously rewarded—a crystalline, concentrated brew, with plenty with zing, is your prize.
Measure out 2,000 grams (two liters) of water.
Place the Filtron’s rubber cap in the hole at the bottom of the device.
Wet the wool filter and place it in the circular groove at the bottom of the Filtron. You’ll want to make sure this is in evenly; otherwise, the extraction may be subpar.
Unfold your filter and place it in the Filtron. It will be a slightly loose fit. Secure it evenly and fold where necessary.
Grind the coffee finely into a large nonreactive bowl.
Add your coffee to the Filtron, then give it a few shakes to level the bed.
Pour your water over the grounds—gradually and carefully—in a series of concentric circles.
Submerge the grounds with a butter knife or bamboo paddle.
Place the plastic disc filter on top of the filter, then place the plastic top component on top of that. Let steep for 12 hours.
Here’s where you’ll need a friend. Carefully position the Filtron over your carafe and swiftly pull out the rubber stopper. Often, you have a couple of seconds before the flow of coffee begins.