tags: [] - coffee/brewing aliases: - Cold brew method - Cold water extraction - Cold steep

Cold Brewing¶

Overview¶

Cold brewing is the process of extracting coffee using cold or room-temperature water over an extended period — typically 12–24 hours — rather than the hot water and short contact times used in conventional brewing methods. The absence of heat produces a fundamentally different extraction chemistry: cold water extracts fewer acidic compounds and bitter chlorogenic acid degradation products, resulting in a naturally smoother, lower-acid, higher-sweetness cup character compared to equivalent hot-brewed coffee. Cold brewing produces a concentrate or ready-to-drink beverage consumed cold and is one of the fastest-growing segments in the specialty coffee market.

Cold Brewing vs. Iced Coffee¶

Cold brewing is distinct from iced coffee (sometimes called "flash brew"):

Method	Process	Character
Cold brew	Cold/room temperature water; 12–24 hour steep	Low acid; smooth; high sweetness; low brightness
Iced coffee / flash brew	Hot brewed directly onto ice; short brew time	Preserves acid structure and brightness; lighter body

Cold brewing prioritises smoothness and low acidity; flash brew preserves the origin character of hot-brewed coffee while serving cold.

Extraction Chemistry at Low Temperatures¶

Temperature profoundly affects extraction kinetics: - Slower diffusion: Dissolved compounds diffuse from the coffee particle into water more slowly at lower temperatures — requiring much longer contact time to achieve equivalent extraction yield - Selective extraction: Different compound classes have different temperature dependencies. Acids (citric, malic, acetic) and some chlorogenic acid derivatives extract less readily in cold water, producing the characteristic low-acid profile - Less hydrolysis: Thermal hydrolysis reactions that produce certain bitter compounds are absent or greatly reduced — contributing to the perceived smoothness - Volatile aromatics: Cold water retains more volatile aromatic compounds that would be driven off by steam in hot brewing

Brew Methods¶

Immersion Cold Brew¶

The most common approach — coffee grounds steep in cold or room-temperature water in a sealed vessel:

Grind coarsely — coarser than French press to reduce over-extraction risk over the long steep
Combine — coffee and water at approximately 1:7 to 1:10 ratio (for concentrate: 1:5); stir briefly
Steep — refrigerator: 18–24 hours; room temperature: 12–16 hours
Filter — pour through a fine metal mesh, then through a paper filter or coffee sock to remove fine particles
Dilute to serve — concentrates typically served at 1:1 to 1:2 dilution with water, milk, or ice

Slow Drip / Kyoto-style Cold Brew¶

Cold water drips slowly through coffee at approximately 1 drop per second over 3–12 hours in a tall glass tower apparatus. Produces a brighter, more complex cup than immersion cold brew because the continuous fresh-water contact drives more even extraction.

Brewing Parameters¶

Parameter	Immersion concentrate	Immersion ready-to-drink
Brew ratio	1:5 to 1:7	1:8 to 1:12
Grind size	Coarse	Coarse
Water temperature	4°C (refrigerator) or room temperature (20°C)	4°C (refrigerator) or room temperature
Steep time (refrigerator)	18–24 hours	16–24 hours
Steep time (room temperature)	12–16 hours	10–14 hours

Room-temperature brewing is faster but increases microbial activity risk — consume promptly or refrigerate after brewing.

Shelf Life¶

Cold brew has longer shelf life than hot-brewed coffee: - Concentrate: 10–14 days refrigerated (sealed) - Diluted / ready-to-drink: 7–10 days refrigerated - Once diluted, flavour degrades faster — dilute per serving rather than in bulk

Nitrogen Cold Brew (Nitro)¶

Nitro cold brew infuses cold brew concentrate with nitrogen gas (N₂) under pressure, served through a stout-beer tap. Nitrogen produces fine, stable bubbles that create a creamy, Guinness-like mouthfeel and a cascading visual effect. Nitro cold brew is served at cellar temperature (approximately 8–10°C), not over ice, to preserve the nitrogen head. It has become commercially significant in ready-to-drink canned coffee products.

Key Facts¶

Cold brewing uses cold/room-temperature water and 12–24 hours contact time instead of hot water and short contact time
Produces lower acidity, higher perceived sweetness, and smoother texture than hot-brewed coffee
Cold water selectively under-extracts acids and bitter compounds — not simply "slow hot brewing"
Standard concentrate ratio: 1:5 to 1:7; dilute 1:1 to 1:2 before serving
Refrigerator brewing (4°C) takes 18–24 hours; room temperature (20°C) takes 12–16 hours
Nitro cold brew infuses with nitrogen for creamy mouthfeel and cascading visual effect

References¶

Changelog¶

Date	Change
2026-04-28	Note created

This article is part of All-About-Coffee.com - The comprehensive coffee knowledgebase.