We’ve been talking all about brewing coffee at home in our past few blog posts including all about water, all about ratios, all about grind, and all about filters. All these items can be for naught with a poor brewing technique. Insert the concept of optimum balance.
Through studies it’s been determined that people generally prefer a 1.25% flavor and 98.75% water-soluble concentration, called concentration or strength. The concentration is affected by brewing formula and time (basically all the pieces we talked about earlier). The flavor compounds in coffee dissolve at different rates which is why it’s essential to stop extraction before flavors turn astringent. When the flavor is extracted, acids come first, then sugars, bitterness, and astringency.
When the flavors are extracted, some of the coffee is being dissolved, such as the sugars, acids, and proteins. While 27-35% can be extracted, the best flavors occur when 18-22% of the coffee’s mass is dissolved, called soluble yield.
Beyond the previous coffee home brewing concepts, wetting is another important part. The purpose of wetting is to create a coffee and water slurry which helps to release the gasses in the coffee and influence the flow rate of extraction. Good quality drip machine will handle this automatically. For methods like an aeropress or pour over is handled through a brief stir.