Flash Brewing
Definition
A Japanese iced tea technique where hot water is poured over tea leaves directly onto ice, rapidly cooling the brew while preserving bright, aromatic compounds that slow cold-brewing cannot capture. Flash brewing produces a vivid, complex iced tea in minutes rather than hours.
Details
Flash brewing (also called Japanese iced tea method or kooridashi variation) bridges the gap between hot brewing and cold brewing for iced tea. The method uses half the normal water volume at full temperature, brewed directly onto an equal weight of ice. As the hot brew contacts the ice, it cools almost instantly, locking in volatile aromatic compounds that would dissipate during slow cooling or remain unextracted during cold brewing. The result is an iced tea with the brightness and complexity of hot-brewed tea but the refreshing temperature of a cold drink. The technique works exceptionally well with Japanese green teas (sencha, gyokuro), which develop vibrant umami and floral notes under hot extraction that cold water cannot access. It also produces excellent iced Darjeeling, where the muscatel character shines in a way that cold brew cannot replicate. The key ratio: use 1.5x the normal leaf amount, half the normal water volume at full brewing temperature, and fill the serving vessel with ice before pouring the hot brew through. Stir briefly and serve immediately. Flash-brewed tea should be consumed within 30 minutes for optimal flavor.