Cold steep iced tea exists in the shadow of cold brew coffee, but it deserves equal attention. The method is identical—submerge tea leaves in room-temperature water for 8-12 hours—yet the results taste completely different. Green and white teas become impossibly clean and delicate. Black teas lose their astringency without losing their character. At Twinings' London headquarters, head blender Michael Strand explained that cold water extraction avoids the harsh compounds that hot water pulls from leaves. Chlorophyll and certain tannins stay behind, leaving a concentrate that tastes alive rather than flat. Dilute it with water or milk; it becomes a silky base for iced tea that rivals fresh-brewed quality. The Concentration Sweet Spot The ratio matters: one ounce of premium tea leaves to four cups of water produces a concentrate that stays fresh in the fridge for two weeks. Unlike hot-brewed concentrate, which oxidizes and dulls over days, cold-steeped tea holds its flavor through the week. Strand recommends using whole-leaf teas—tea bags don't work as well because the cold water temperature struggles to fully extract from finer dust particles.