Grind 100g of coffee coarsely — it should look like raw sugar.
0:05Use a quality burr grinder for consistent coarseness. Blade grinders create too many fines.
Add grounds to a large jar or pitcher. Pour 700ml of room-temperature filtered water over them.
0:05Stir gently to ensure all grounds are wet. Cover and place in the refrigerator.
0:02Steep for 14-18 hours. Do not agitate during steeping.
16:00:00Steeping longer than 20 hours can introduce woody, astringent flavors.
Strain through a fine mesh strainer, then filter again through cheesecloth or a paper filter for clarity.
0:10Store concentrate in a sealed container in the fridge. Dilute 1:1 with water or milk to serve.
Concentrate keeps for up to 2 weeks refrigerated.