Bloom

Blooming is the first step in pour-over and some drip brewing, where you pour just enough hot water to saturate the grounds, usually two to three times the coffee's weight, and let it sit for thirty to forty five seconds before continuing. Fresh coffee holds carbon dioxide gas from roasting, and that gas needs to escape before water can evenly soak into the grounds.

Skipping the bloom or rushing through it causes uneven wetting, where water channels around gas bubbles instead of soaking the coffee bed evenly, leading to inconsistent extraction and a cup that can taste both sour and bitter at once. Watching the bloom is also a useful freshness check, since coffee that barely bubbles or swells is likely stale and past its best flavor window.

A gooseneck kettle makes blooming easier because its thin spout lets you pour slowly and evenly over the whole coffee bed rather than dumping water in one spot. A common mistake is pouring too much water during the bloom, which starts extraction too early, or not waiting long enough for the gas to fully release before the main pour.