What Is Cold Brew? The Complete Definitional Guide to Coffee's Smoothest Drink

Cold brew is the coffee category that confuses more drinkers than any other. It looks like iced coffee in the glass, comes from chains that also sell iced coffee, and even regular customers often can’t articulate what makes the two different. The answer is simple: temperature. Cold brew is coffee that was brewed in cold water. Iced coffee is coffee that was brewed in hot water and then cooled. Everything else — the smoother taste, the higher caffeine, the longer shelf life, the chocolatey-sweet character — flows from that one decision.

This guide covers exactly what cold brew is, where it came from (Japan, the Dutch East Indies, and Portland), how it differs from every adjacent drink, and what to expect from caffeine, calories, and variations.

The Short Answer

A cold brew is coffee made by steeping coarsely ground beans in cold or room-temperature water for 12 to 24 hours, then filtering out the grounds. No heat is ever applied. The finished drink is smooth, low-acid, slightly sweet, and naturally chocolatey, with higher caffeine than equivalent-size iced coffee.

Where the Name “Cold Brew” Comes From

The name is purely descriptive: “cold brew” simply means “coffee that was brewed in cold water.” The term contrasts the dominant historical method — brewing coffee in hot water at near-boiling temperature — and identifies a different brewing process based on temperature alone.

The English phrase entered widespread café usage in the 1990s and 2000s as American specialty coffee shops began featuring it as a menu item, but the brewing technique itself is much older. Japanese mizudashi (literally “water-extracted”) coffee has existed since at least the 17th century, and the elaborate Kyoto-style slow-drip cold brew towers — where ice-cold water drips one drop at a time through a coffee bed for 3 to 8 hours — predate the modern Western use of the phrase by hundreds of years. The English term is recent; the practice is centuries old.

A Brief History of Cold Brew

Cold brew has two independent historical roots and one modern revival. Understanding all three explains why cold brew suddenly seemed everywhere starting around 2010 — it didn’t appear from nowhere.

Japanese Mizudashi and Kyoto-Style Slow-Drip (17th century onward)

Japan has the longest unbroken tradition of cold-water coffee. Mizudashi (“water extracted”) cold brew is a tradition that dates to at least the Edo period (17th–19th centuries), when Japanese coffee culture began experimenting with cold-water immersion as a way to produce a smoother, less acidic brew suited to the warm humid summers. The simplest mizudashi method uses a glass pitcher with a fine-mesh basket: coarse coffee grounds go in the basket, cold water fills the pitcher, and the assembly steeps in the fridge for 8–12 hours.

The more elaborate Kyoto-style cold brew uses a tall glass tower with three chambers: the top chamber holds ice water, which drips at one drop per second through a middle chamber of coffee grounds, into a bottom chamber where the finished cold brew collects. A full Kyoto brew takes 3 to 8 hours. The technique is associated with Kyoto’s century-old coffee shops and produces a notably clean, tea-like cold brew compared to immersion methods.

Dutch Coffee Trade and Indonesian Cold Brew (1600s)

Dutch traders in the colonial-era Dutch East Indies (modern Indonesia) reportedly developed a similar cold-water steeping method in the 1600s. The story — though documentation is thin — is that sailors needed a coffee that could be brewed without a fire, kept room-temperature for weeks at sea, and consumed cold. Cold-water steeping fit all three constraints. Whether this was independently invented in Indonesia or learned from Japanese trade contacts is unclear, but the Dutch-Indonesian connection is the second commonly cited origin point in cold brew’s history. Some historians argue Kyoto-style slow drip itself may have been introduced to Japan by Dutch traders, in which case both stories trace to the same root.

Modern American Cold Brew (1960s–2010s)

The modern Western cold brew movement is much more recent. The Toddy cold brew system — a home cold brew brewer using a felt filter, still sold today — was invented in 1964 by chemical engineer Todd Simpson, who reverse-engineered a Peruvian cold-water brewing tradition he had encountered. Toddy cold brew quietly served the specialty market for four decades but never broke into the mainstream.

The mainstream catalyst was Portland-based Stumptown Coffee Roasters, which launched its bottled cold brew in 2011 and made cold brew a national supermarket category in the U.S. Starbucks added cold brew to its U.S. menu in March 2015, and by 2017 cold brew was a fixture at every major coffee chain. The 2010s cold brew boom was the third historical moment — after 17th-century Japan and 17th-century Indonesia — that the brewing method went mainstream, and it’s the one that brought cold brew to global café menus.

What’s Actually in Cold Brew

A traditional cold brew has two ingredients. That’s the entire standard recipe.

1. Coarsely ground coffee

The grind is intentionally coarse — similar to French press or slightly coarser. Fine grinds (like espresso or pour-over) over-extract during a 12-to-24-hour steep, producing a muddy, harshly bitter result. Coarse grinds extract more slowly and evenly, which is what you want for a long contact time.

Almost any roast level works for cold brew, but medium-to-dark roasts are the most popular choice because their chocolate, caramel, and nutty flavor notes pair particularly well with the cold extraction profile. Single-origin light roasts can produce interesting fruity cold brews — experiment once you have the basics down.

2. Cold or room-temperature water

The water is never hot. Filtered tap water at room temperature (about 70°F / 21°C) is standard; refrigerator-cold water (about 40°F / 4°C) is also fine and produces a slightly slower extraction. Some recipes start with room-temperature steep for the first 4 hours and then move to the fridge for the remaining 8–20 hours, but a single-temperature brew works just as well.

The standard concentrate ratio is 1:5 by weight — 1 part coffee to 5 parts water. For 8 oz (240 ml) of ready-to-drink cold brew, that means about 1.5 oz (45 g) of ground coffee to 7.5 oz (225 ml) of water, steeped 16–18 hours, then diluted 1:1 with water or milk before serving. For a 1:8 ready-to-drink ratio that you sip straight, use about 1 oz (30 g) of coffee per 8 oz (240 ml) of water.

After steeping, filter the grounds out using a paper filter, fine-mesh strainer, or cheesecloth. The remaining liquid is cold brew. Store in the fridge for up to 2 weeks.

For the full step-by-step recipe with French press and mason jar methods, see our cold brew recipe guide.

Why Cold Brew Tastes Different (The Chemistry)

Hot water and cold water extract coffee very differently. Hot water (around 200°F / 93°C) is fast and aggressive: it dissolves acids, oils, sugars, and bitter compounds quickly, which is why hot brewed coffee finishes in 3–5 minutes. Cold water (around 70°F / 21°C) is slow and selective: it dissolves sugars and some flavor compounds easily, but extracts acids and bitter compounds far less efficiently, even over 12–24 hours.

The practical consequences:

• Lower acidity: Cold brew measures around pH 6.0–6.5 vs. pH 4.85–5.0 for hot brewed coffee. The chlorogenic acids that give hot coffee its characteristic bright, sour edge are extracted much less in cold water. People with acid-reflux sensitivity or stomach issues often tolerate cold brew better than hot coffee.
• Smoother, sweeter mouthfeel: Without the bitter compounds that hot water releases, cold brew tastes naturally sweeter even with no added sugar. The chocolate, caramel, and nutty notes of medium-dark roasts come forward without being masked by acidity.
• Heavier body: Cold brew has a syrupy, almost oily mouthfeel compared to hot drip coffee. The long steep time extracts more soluble solids overall, even though it leaves the acids behind.
• Less aroma: Volatile aromatic compounds need heat to evaporate into the nose. Cold brew has noticeably less aroma than hot coffee, which is part of why it tastes “calmer” — less of what coffee experts call “olfactory complexity.”
• Longer shelf life: Cold brew never went through the rapid oxidation that hot coffee experiences, and what’s extracted is chemically more stable. A sealed jar of cold brew concentrate lasts 1–2 weeks in the fridge with minimal flavor change.

Cold Brew vs. Other Coffee Drinks

Cold brew vs. iced coffee

The most-confused pairing. They look identical in a glass and are both served cold, but they are made completely differently. Iced coffee is hot-brewed coffee — drip, pour-over, French press, or espresso — that has been cooled and poured over ice. The brewing happened with hot water; only the serving is cold. Cold brew is brewed with cold water from start to finish; it never sees heat at any point.

The taste difference is immediate. Iced coffee is bright, acidic, and tastes like hot coffee that’s been chilled (because it is). Cold brew is smooth, low-acid, and tastes like a different category of drink entirely. Iced coffee is best when brewed double-strength specifically for ice (so the dilution doesn’t kill the flavor); cold brew is best straight or with minimal milk. For the full breakdown, see our dedicated cold brew vs. iced coffee guide.

Cold brew vs. nitro cold brew

Nitro cold brew is regular cold brew infused with nitrogen gas under pressure at serving time. The coffee inside is identical — same beans, same cold-water extraction, same 12–24 hour steep. The nitrogen does three things: it adds a creamy, almost milky mouthfeel without any actual milk; it produces a cascading visual effect when poured, similar to a Guinness; and it masks bitterness so the drink tastes naturally sweeter than the same cold brew served still.

Nitro is served on draft from a tap, never with ice (the ice would disrupt the nitrogen bubbles). It’s a serving format, not a brewing method. Nitro cold brew at Starbucks is the same cold brew base as the regular cold brew — the only difference is the tap.

Cold brew vs. French press

Both methods use full immersion (coffee fully in contact with water), but the temperature and time are completely different. French press uses hot water (around 200°F / 93°C), 4 minutes of steeping, and a medium-coarse grind, then plunges to filter. Cold brew uses cold water, 12–24 hours of steeping, and a coarser grind, then filters through paper or fine mesh.

The drinks taste very different. French press is bold, full-bodied, slightly bitter, and has noticeable acidity. Cold brew is smooth, low-acid, and slightly sweet. Interestingly, you can use a French press to make cold brew at home — just use cold water and steep for 12+ hours instead of 4 minutes. Many home brewers do exactly this; the only adjustment is grind size (slightly coarser than standard French press) and the much longer steep time.

Cold brew vs. espresso

Two opposite extraction philosophies. Espresso uses near-boiling water forced through finely ground coffee under 9 bars of pressure for 25–30 seconds, producing a 1–2 oz concentrated shot. Cold brew uses room-temperature water steeped through coarsely ground coffee for 12–24 hours under no pressure, producing a smooth concentrate diluted to 8–16 oz of finished drink.

A 1 oz shot of espresso has 64 mg of caffeine; an 8 oz cup of cold brew has 100–155 mg. So per-ounce, espresso is about four times stronger; per-cup, cold brew has more caffeine because the cup is much larger. The flavor profiles are also opposite: espresso is intense, syrupy, and complex with prominent crema; cold brew is smooth, mellow, and quietly sweet. For more on this comparison, see our cold brew vs. espresso guide.

Caffeine in Cold Brew

The caffeine question depends entirely on whether you mean concentrate, ready-to-drink, or chain-café cold brew.

Cold brew is generally higher caffeine than equivalent-size iced coffee (which has 80–120 mg per 8 oz), slightly higher than equivalent-size hot drip coffee (95–120 mg per 8 oz), and lower than espresso on a per-oz basis but higher per-cup because cold brew is served in 8–16 oz while espresso is 1–2 oz.

Calories in Cold Brew

Plain black cold brew has essentially zero calories. All cold brew calories come from add-ins.

The pattern is clear: black cold brew is essentially calorie-free; sweet cream and flavored variations add 100–250 calories per drink. The most popular customizations — sweet cream, vanilla, salted caramel — are all in the 100–220 calorie range.

Variations of Cold Brew

Cold brew has spawned a small ecosystem of variations, each modifying either the brewing method, the serving format, or the additions.

Nitro cold brew. Cold brew infused with nitrogen gas, served on draft. Creamy, frothy, naturally sweet without sugar. The most popular café variation.

Kyoto-style slow drip. Cold water dripped one drop at a time through a coffee bed for 3–8 hours, using a tall glass tower. Produces a notably clean, tea-like cold brew. A specialty-shop offering.

Sweet cream cold brew. Cold brew topped with vanilla or unflavored sweet cream foam (a half-and-half / vanilla syrup blend lightly whipped). The signature Starbucks variation.

Flash brew. Hot brewing directly over ice, using ice as part of the brewing water (typically half ice, half hot water). Faster than cold brew (5 minutes), tastes more like iced coffee than true cold brew, but produces a noticeably less acidic cup than standard hot-brewed-then-cooled iced coffee. A common Japanese café method.

Dirty cold brew. Cold brew with a shot of espresso poured on top (similar to a “dirty chai”). The visible layer of espresso sinks slowly into the cold brew, producing a heavier, more caffeinated drink with two coffee flavor profiles in one glass.

Cold brew tonic. Cold brew over ice topped with tonic water and a citrus garnish. Effervescent, bitter-sweet. Popular as a non-alcoholic café cocktail in the summer.

Cold brew float. Cold brew over a scoop of vanilla ice cream. A nostalgic café dessert combining cold brew’s smoothness with melting vanilla ice cream.

Decaf cold brew. Same brewing method using decaf beans. Caffeine drops to 5–10 mg per 8 oz; flavor profile remains broadly similar to caffeinated cold brew, though slightly thinner.

Common Misconceptions About Cold Brew

“Cold brew is the same as iced coffee.” No — they are made completely differently. Iced coffee is hot-brewed coffee that has been cooled. Cold brew is coffee that was brewed with cold water and never heated. The flavor profiles are clearly distinguishable side by side.

“Cold brew is always stronger than regular coffee.” Cold brew concentrate is much stronger than hot drip coffee. But concentrate is rarely consumed straight; it’s diluted before drinking. At typical drinking ratios (1:1 dilution or ready-to-drink 1:8 brews), cold brew is roughly equivalent to or modestly stronger than hot drip.

“Cold brew is just hot coffee that was brewed and put in the fridge.” No — that’s iced coffee. Cold brew never sees hot water. The brewing temperature is the entire categorical distinction.

“Cold brew has no acidity at all.” Cold brew has lower acidity than hot brewed coffee — measurably lower (pH 6.0–6.5 vs. pH 4.85–5.0) — but it is not acid-free. People with severe acid sensitivity can still react to cold brew, just less than to hot coffee.

“Starbucks invented cold brew.” Starbucks introduced cold brew to its U.S. menu in March 2015, but the brewing method is centuries older (Japanese mizudashi, 17th century) and the modern American cold brew movement was driven by smaller specialty roasters in the 2000s. The bottled cold brew that catalyzed the U.S. mainstream was launched by Stumptown Coffee in Portland in 2011 — four years before Starbucks added it to the menu. Starbucks scaled cold brew. It didn’t invent it.

How to Order Cold Brew at Different Cafés

At Starbucks (US): Order by size and customization. “Grande Cold Brew” gets you 16 oz of plain black cold brew (205 mg caffeine, 5 calories). For sweetened, “Grande Vanilla Sweet Cream Cold Brew” is the most popular. For nitro, “Grande Nitro Cold Brew” — available only at locations with nitro taps. Trenta (30 oz) is iced-coffee and cold-brew only; you can’t order a Trenta latte.

At a US specialty café: Order “cold brew” and expect it to come straight (no ice, no milk) at 8–12 oz. Some specialty shops will have nitro on draft; ask. Specialty cafés often brew their cold brew to a less-diluted ratio than chains, so it’ll taste more concentrated.

In Japan: Order mizudashi (水出し) at any traditional kissaten or specialty café, or look for “水出しコーヒー” on the menu. Kyoto-style slow-drip cold brew (京都式コーヒー) is also widely available. Both are offered alongside iced coffee (アイスコーヒー), which is the hot-brewed-then-cooled variety.

In the UK and Europe: Most specialty cafés now offer cold brew under that English name. Some menus distinguish “cold brew” from “slow drip” (Kyoto-style) and “flash brew” (hot-brewed-on-ice). When in doubt, ask.

In Australia and New Zealand: Cold brew is widely available at specialty cafés, often labeled “cold brew” or sometimes “cold drip” (which is technically Kyoto-style slow drip, though the terms are used loosely).

How to Make Cold Brew at Home

The full step-by-step recipe (concentrate vs. ready-to-drink, mason jar method, French press method, ratios, brew times, and storage) is in our cold brew recipe guide. The short version:

1. Coarse-grind 1.5 oz (45 g) coffee — about 1/2 cup of whole beans ground to French-press coarseness.
2. Add to a 1-quart mason jar with 4 cups (about 950 ml) cold filtered water. Stir to fully wet the grounds.
3. Cover and steep 16–18 hours at room temperature (or 20–24 hours in the fridge).
4. Filter through a paper coffee filter or fine-mesh strainer. For extra clarity, filter twice.
5. Store in a sealed jar in the fridge for up to 2 weeks. Dilute 1:1 with water, milk, or ice when serving.

The 1:5 ratio above produces a concentrate. For ready-to-drink cold brew that you sip straight, use 1 oz (30 g) coffee per 4 cups (950 ml) water, steep 12–18 hours, and skip the dilution.

Bottom Line

Cold brew is coffee made by steeping coarsely ground beans in cold water for 12 to 24 hours. The cold extraction produces a fundamentally different drink from hot-brewed coffee: smoother, less acidic, slightly sweeter, with higher caffeine when undiluted and a 1–2 week shelf life in the fridge. The brewing method dates to 17th-century Japan (mizudashi) and 17th-century Indonesia (Dutch trade); the modern American cold brew movement is much more recent — Stumptown bottled cold brew in 2011, Starbucks added it to the menu in 2015, and the 2010s cold brew boom made it a global café category.

Cold brew is not the same as iced coffee. Iced coffee is hot-brewed coffee that has been cooled; cold brew is coffee that was brewed cold and never heated. The flavor difference is immediate and clearly distinguishable.

For the full how-to-make-cold-brew recipe, see our cold brew recipe guide. For the iced coffee comparison, see cold brew vs. iced coffee. For the espresso comparison, see cold brew vs. espresso. For the cold foam topping, see how to make cold foam. For a sweet cream variation, see vanilla sweet cream cold brew.

Frequently Asked Questions

What is cold brew?

A cold brew is coffee made by steeping coarsely ground coffee beans in cold or room-temperature water for 12 to 24 hours, then filtering out the grounds. No heat is ever applied at any point in the process. The result is a smooth, low-acid, slightly sweet coffee concentrate that is typically diluted with water or milk before drinking. Cold brew is not the same as iced coffee — iced coffee is hot-brewed coffee that has been cooled and poured over ice. Cold brew never sees hot water. Because cold-water extraction does not pull out the same acidic and bitter compounds that hot-water extraction does, the finished drink tastes noticeably smoother, less sour, and slightly chocolatey or caramel-like compared to a hot-brewed equivalent.

What is in cold brew?

Two ingredients: coarse-ground coffee and cold water. That’s the entire standard recipe. The typical ratio is 1 part coffee to 4–5 parts water for a concentrate (which is then diluted), or 1:8 for ready-to-drink. The grind is intentionally coarse — the same as for a French press or even slightly coarser — because finer grinds steeped for 12+ hours produce muddy, over-extracted results. The water is room temperature or refrigerator-cold; never hot. After 12 to 24 hours of steeping, the grounds are filtered out (paper filter, fine mesh, or cheesecloth) and what remains is cold brew.

Where does the name “cold brew” come from?

Literally from the brewing temperature. “Cold brew” simply means “coffee that was brewed in cold water,” distinguishing it from the much older standard of brewing coffee in hot water. The term entered widespread English-language café usage in the 1990s and 2000s as American specialty cafés began offering it as a menu item, but the brewing method itself is centuries older — Japanese cold-water “mizudashi” coffee dates to at least the 17th century, and Kyoto-style slow-drip cold brew has been a tradition in Japan for hundreds of years.

Is cold brew the same as iced coffee?

No. They look similar in a glass but they are made completely differently. Iced coffee is hot-brewed coffee that has been chilled or poured over ice — the brewing happened with hot water. Cold brew is coffee that was brewed with cold water and never heated. The two taste different: iced coffee retains the bright acidity and complexity of hot extraction (then cooled), while cold brew is smoother, less acidic, and slightly sweeter because cold water doesn’t extract the same acidic and bitter compounds.

Where did cold brew originate?

The brewing method has two independent origins. In Japan, “mizudashi” (water-brewed) coffee has been a tradition since at least the 17th century, and the elaborate Kyoto-style slow-drip cold brew tower is a centuries-old Japanese specialty. Separately, Dutch traders in colonial-era Indonesia in the 1600s reportedly steeped coffee beans in cold water for sailors who needed a stable, room-temperature coffee for long sea voyages. The modern American cold brew movement is much more recent: Portland’s Stumptown Coffee Roasters launched its bottled “Stumptown Cold Brew” in 2011, and Starbucks added cold brew to its U.S. menu in 2015.

What’s the difference between cold brew and iced coffee?

Brewing temperature is the entire difference. Cold brew uses cold water and 12–24 hours of steeping; iced coffee uses hot water (about 200°F / 93°C) and a few minutes of brewing, then is cooled. The downstream consequences: cold brew is less acidic, smoother, slightly sweeter, has higher caffeine when undiluted, lasts 1–2 weeks refrigerated, and has a heavier mouthfeel. Iced coffee is brighter, more acidic, less sweet, has lower caffeine, lasts only 1–2 days, and has a lighter mouthfeel.

What’s the difference between cold brew and nitro cold brew?

Nitro cold brew is regular cold brew that has been infused with nitrogen gas under pressure, creating a creamy, frothy texture and a cascading visual effect when poured. The coffee inside is the same — same beans, same cold-water extraction, same 12–24 hour steep. The only difference is the nitrogen infusion at serving time, which adds a velvety, almost milky-tasting mouthfeel without any actual milk or sweetener. Nitro is typically served on draft from a tap (like beer) and is not topped with ice.

What’s the difference between cold brew and French press?

Brewing temperature, brewing time, and grind size — though they share an immersion brewing principle. French press uses hot water (about 200°F / 93°C), 4 minutes of steeping, and a medium-coarse grind. Cold brew uses cold water, 12–24 hours of steeping, and a coarser grind. You can actually use a French press to make cold brew at home — just use cold water and steep for 12+ hours instead of 4 minutes — and many home brewers do exactly that.

How much caffeine is in cold brew?

It depends on whether you mean concentrate or diluted ready-to-drink cold brew. Cold brew concentrate (1:4 or 1:5 ratio) typically contains 200–280 mg of caffeine per 8 oz. Diluted 1:1 with water or milk, that drops to about 100–140 mg per 8 oz of finished drink. Ready-to-drink cold brew (1:8 ratio, sold pre-diluted) contains about 130–155 mg per 8 oz. A Starbucks Grande (16 oz) cold brew has about 205 mg of caffeine; a Starbucks Grande nitro cold brew has 280 mg.

How many calories are in cold brew?

Plain black cold brew has essentially zero calories — about 5 calories per 16 oz cup. All cold brew calories come from add-ins: simple syrup (about 50 calories per pump), 2% milk (about 30 calories per oz), sweet cream cold foam (typically 100–150 calories per topping), or chocolate / caramel / vanilla syrups (60–80 calories each). A Starbucks Grande Sweet Cream Cold Brew has 110 calories.

Is cold brew stronger than regular coffee?

It depends on how it’s served. Cold brew concentrate is much stronger than regular hot coffee. But concentrate is rarely consumed straight; it’s diluted 1:1 with water or milk before drinking. Diluted cold brew is roughly 100–150 mg caffeine per 8 oz, comparable to or slightly stronger than hot drip coffee. The “cold brew is stronger” belief is true in absolute caffeine terms when comparing concentrate to drip, but at typical drinking ratios cold brew is roughly equivalent or modestly stronger than hot coffee.

Why does cold brew last so long in the fridge?

Three reasons. First, cold brew was never heated, so it never went through the rapid oxidation that gives hot coffee its “stale” taste within hours of brewing. Second, the cold extraction pulls out fewer of the volatile aromatic compounds that degrade quickly. Third, refrigeration slows microbial activity and chemical degradation. A sealed jar of cold brew concentrate keeps for 1–2 weeks in the fridge with minimal flavor change.

Can you heat up cold brew?

Technically yes, but it defeats most of the point. Heating cold brew destroys some of the smooth, low-acid character that makes it special — heat extracts more of the acidic and bitter compounds that cold extraction left behind in the grounds. Some cafés do offer “hot cold brew” as a winter menu item, and it’s perfectly fine, but if you want hot coffee that tastes like coffee, brew it hot.

How do I order cold brew at Starbucks?

The base “Cold Brew” is plain unsweetened black cold brew, available in Tall (12 oz, 155 mg caffeine), Grande (16 oz, 205 mg), Venti (24 oz, 310 mg), and Trenta (30 oz, 360 mg). Variations include Vanilla Sweet Cream Cold Brew, Salted Caramel Cream Cold Brew, Chocolate Cream Cold Brew, and Nitro Cold Brew (only at locations with nitro taps; Tall and Grande only).

What’s the best ratio for making cold brew at home?

For a versatile concentrate that you dilute when serving, use 1:5 by weight (1 cup of coffee grounds to 5 cups water). Steep 16–18 hours at room temperature or 20–24 hours in the fridge. For ready-to-drink cold brew that you sip straight, use 1:8 (about 1/2 cup coffee to 4 cups water) and steep 12–18 hours. Use a coarse grind, filter through paper or fine mesh after steeping, and store in the fridge for up to 2 weeks.