Cold Brew

Cold brew coffee has roots in Dutch trading in the 17th century, where cold water extraction was used to make coffee that could be transported on ships. The method became popular in Japan (where it is known as mizudashi) and Latin America. In the United States, cold brew gained mainstream popularity in the 2010s, with companies like Blue Bottle, Stumptown, and Starbucks popularizing the method.

Cold brew's origins are traced to Dutch traders in the 1600s, who used cold water extraction to create coffee concentrate for sea voyages. The modern cold brew movement in the US was popularized by specialty coffee roasters in the 2000s-2010s. The Toddy cold brew system, invented by Todd Simpson in 1964, was an early commercial cold brew device in the US.

Coarse ground coffee is steeped in cold or room-temperature water for 12-24 hours. The long extraction time compensates for the low temperature. The resulting concentrate is filtered (usually through paper or cloth) and served diluted with water, milk, or ice at a ratio of 1:1 to 1:3.

Cold brew uses time instead of temperature to extract coffee compounds. Cold water dissolves different compounds than hot water: it extracts fewer acids and bitter compounds, resulting in a smoother, sweeter, and lower-acidity brew. The long steep time (12-24 hours) allows sufficient extraction of sugars and other soluble compounds. The result is a concentrate with a different chemical profile than hot-brewed coffee: less acidity, different aromatic compounds, and higher caffeine content per serving.

No active flow during brewing. Coffee steeps in still water (immersion). The filter is used only after brewing to separate grounds from the concentrate.

Typical Extraction Yield: 18-22%. Cold brew extracts within the standard range, but extracts different compounds than hot brewing.

Typical Strength (TDS): 3-5% TDS (concentrate). When diluted 1:1, the strength is approximately 1.5-2.5% TDS, similar to strong filter coffee.

• •Grinding too fine, causing over-extraction and cloudy, muddy concentrate
• •Steeping too long (over 24 hours), which can extract undesirable bitter compounds
• •Not filtering thoroughly, leaving sediment in the concentrate
• •Using old or stale coffee, which produces flat-tasting cold brew
• •Diluting too much or too little at serving time

• •Use a coarse grind to prevent over-extraction and make filtering easier
• •Steep in the refrigerator for a cleaner, smoother taste
• •Agitate (stir) the slurry once at the beginning to ensure all grounds are saturated
• •Filter twice: first through a coarse mesh, then through paper for clarity
• •Store the concentrate in the refrigerator for up to 2 weeks
• •Dilute with cold water, milk, or serve over ice at 1:1 to 1:3 ratio

• •Slow drip (Kyoto-style): use a tower that drips cold water over coffee at 1 drop per second for 6-12 hours for a different flavor profile
• •Nitro cold brew: infuse the concentrate with nitrogen gas for a creamy, stout-like texture
• •Hot bloom cold brew: bloom the coffee with hot water for 30 seconds before adding cold water to extract aromatic compounds that cold water alone misses
• •Coffee-cocktail base: use cold brew concentrate as a base for coffee cocktails

• •Cold brew has less caffeine than hot coffee. Actually, cold brew concentrate often has more caffeine per serving because the long steep time extracts caffeine efficiently. However, when diluted, the caffeine content per cup is similar.
• •Cold brew is just iced coffee. Iced coffee is hot-brewed coffee served over ice. Cold brew is brewed with cold water over many hours. They are fundamentally different beverages with different flavor profiles.
• •Cold brew is always low-acid. Cold brew is lower in acidity than hot-brewed coffee, but the degree depends on the coffee, ratio, and steep time. Light roasts still produce a brighter cold brew than dark roasts.

Clean the brewing vessel with warm soapy water after each use. If using a Toddy system, clean the felt filter thoroughly and store it damp in the refrigerator. Paper filters are single-use. Clean the dispensing valve or spigot of any brewing vessel regularly.

For Toddy-style systems, replace the felt filter every 10-12 uses or when it becomes clogged. For mason jar systems, replace the mesh filter if it tears. Glass vessels are durable but fragile; handle with care. Keep the dispensing valve clear of grounds.

• •Chapter 3: Core Brewing Variables
• •Chapter 8: Immersion Brewing

• •Specialty Coffee Association
• •Toddy
• •National Coffee Association