Cold brew used to be whatever was left at the end of the week, steeped overnight. It is now a product cafés order by the kilo and bottlers by the pallet, and it asks different things of a roastery than espresso or filter do. Cold extraction changes which roast level works, the grind is coarse and high-volume, resting rules differ, and the customer's ratio decides how much coffee you sell. This guide takes the roastery through all four.
What cold extraction changes
Hot water at 90–96 °C pulls acids, sugars and the more delicate aromatics out of coffee in minutes. Cold water at fridge temperature, given twelve to twenty-four hours, extracts sugars and body-forming compounds well and acids and light aromatics poorly. Two consequences follow for the roaster:
- Acidity and floral notes largely disappear. A bright washed Ethiopian that sings as a pour-over comes out of a cold brew flat and thin; its best qualities are the ones cold water does not extract.
- Body, sweetness and chocolate carry. Roasts that develop those — medium to medium-dark, with a longer development — translate well, and their consistency is easier to hold across batches.
That is why commercial cold brew leans dark: not only for flavour but for tolerance. A dark, well-developed roast varies less from batch to batch under cold extraction, takes milk and sugar without disappearing, and forgives a customer's imprecise steeping.
Roast level and profile
| Roast level | Typical use in cold brew | Trade-off |
|---|---|---|
| Light | Specialty single-origin cold brew, cold drip | Thin body, tea-like; unforgiving of steep time; needs 7–10 days rest |
| Medium | The all-round choice for cafés serving black and with milk | Caramel and chocolate, low acidity, reliable |
| Medium-dark | Concentrates, ready-to-drink, milk-based cold drinks | Syrupy body; more smoke and gas in the roast |
| Dark | High-volume concentrate | Bold and smoky; ashy if pushed; fastest to stale |
For a wholesale line, medium to medium-dark covers most demand. Roasters who specialise in cold brew describe a profile with a normal drying phase, a steady browning phase, and development extended by a minute or more after first crack — taking the coffee a step darker than the same roastery's espresso, but stopping short of second crack. Roasters commonly quote drop temperatures a few degrees above their espresso profile on the same probe; the figure is machine-specific and belongs in your own trials, not copied. Origin choice follows the same logic: Brazilian, Colombian and Central American coffees with chocolate and nut character are the usual base; bright African coffees are used sparingly or not at all.
Two production consequences of that profile. A longer roast is fewer batches per hour — an extra minute on a 12–15 minute cycle is roughly 7% of capacity — which is the arithmetic of roasting for espresso vs filter applied to a third profile. And a darker, longer roast makes more smoke; a roastery whose cold brew line grows is the one that meets the local emissions rule, covered in how to reduce smoke from a coffee roaster.
The grind is a capacity question
Cold brew is ground coarse — a texture like raw sugar, well above espresso and filter settings — and it is ground in quantity: a café making a few litres of concentrate a day uses hundreds of grams; a bottler uses tens of kilos per batch. Two things follow for a roastery that grinds for its customers.
First, an espresso grinder is the wrong tool: too slow, too fine, too much heat per kilo. A retail or industrial grinder that runs coarse at volume is the right one. Our industrial mills cover this range — the YS-1100M with 120 mm flat burrs at 15–40 kg/h (USD 608 EXW Shenzhen, USD, 2026) and the YS-2200M at 20–50 kg/h, rated 50 kg/h on a drip-coarse setting (USD 688) — and both take 110/220 V.
Second, ground coffee stales fast: grinding exposes a vast surface and most of the carbon dioxide leaves within minutes. Grind as close to delivery as possible, and prefer supplying whole bean with a recommended setting where the customer has a suitable grinder; the retail-grinding case is in bulk coffee grinders for roasteries.
Resting, packaging and shelf life
Cold brew coffee rests differently from espresso. Darker roasts degas fast — a few days, not a week — so a medium-dark cold brew coffee is usually ready to sell three to five days after roasting; light cold brew coffees need longer. The schedule for each SKU belongs in coffee degassing before packaging.
Packaging follows the customer. Cafés take 1 kg valve bags. Bottlers and larger cold brew producers take 5–20 kg bulk bags or lined boxes with a one-way valve, and they will ask for a roast date and a use-by window — commonly two to four weeks for whole bean at the roast level they want. Dark roasts oil up and stale faster, so the window is shorter than for a filter roast. The equipment for bagging at volume is in coffee packaging equipment.
The customer's ratio decides your volume
Cold brew is sold by the litre, and every litre uses a fixed weight of coffee set by the customer's recipe:
| Product | Typical coffee-to-water ratio | Coffee per litre of output |
|---|---|---|
| Ready-to-drink (served as brewed) | About 1:8 | Roughly 125 g |
| Concentrate (diluted 1:1 at service) | About 1:4 to 1:5 | Roughly 200–250 g per litre of concentrate |
A café selling 40 litres of ready-to-drink cold brew a week uses about 5 kg of coffee — a small account. A bottler producing 2000 litres of concentrate a week uses 400–500 kg — a 12 kg roaster's whole week, or a 20 kg machine's comfortable share. Knowing which product the customer makes tells you which machine class the account needs, the calculation in how to sell wholesale coffee to cafés.
Setting up the line
- One profile, medium to medium-dark, developed on a sample roaster and cupped as cold brew, not hot — brew the trial the way the customer will.
- A base of chocolate-and-nut origins, bought in whole bags on a forward contract, since cold brew demand is steady across the year in most markets.
- Roast in a block — cold brew batches together, after lighter coffees — to keep the drum's thermal state and the smoke in one part of the day.
- A coarse-capable grinder for customers who take ground coffee, run close to delivery.
- Valve packaging sized to the account, with roast date and window on every bag.
FAQ
What roast is best for cold brew?
Medium to medium-dark for most commercial use: cold water extracts body, sweetness and chocolate well and acidity poorly, so those roasts translate and stay consistent. Dark roasts suit concentrates and milk drinks; light roasts make a thin, tea-like cold brew that only a specialty menu wants.
Should cold brew coffee be roasted longer?
Roasters who specialise in it extend development after first crack by a minute or more and drop a step darker than their espresso, stopping short of second crack. That costs a little capacity per batch and produces more smoke, both worth planning for.
How coarse should coffee be ground for cold brew?
Coarse — roughly the texture of raw sugar, well above filter settings. At commercial volumes that means a retail or industrial grinder running coarse, not an espresso grinder, and grinding as close to delivery as possible because ground coffee stales within days.
How long should cold brew coffee rest after roasting?
Medium-dark cold brew coffees degas fast and are usually ready three to five days after roasting; light roasts need a week or more. Tell the customer the roast date and a use-by window — commonly two to four weeks for whole bean at these roast levels.
How much coffee does a cold brew customer use?
Ready-to-drink at about 1:8 uses roughly 125 g per litre; concentrate at 1:4 to 1:5 uses 200–250 g per litre of concentrate. A café at 40 L a week is about 5 kg; a bottler at 2000 L of concentrate is 400–500 kg — a full week on a 12 kg roaster.
Does cold brew need its own roasting profile?
Yes, if you want it to taste right and stay consistent — it is a third profile alongside espresso and filter, with its own SKU, resting time and packaging window. Roast it in a block and cup it cold during development.
Final Thoughts
Roast for what cold water extracts — body and sweetness at medium to medium-dark — and plan the grind, resting and packaging as a line rather than a leftover. We build the commercial coffee roasters the profile runs on and the industrial coffee grinders that grind coarse at volume; tell us the customer's litres and we will size both.
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Get a Quote → WhatsApp +86 184 0771 4607Last updated: September 23, 2026