Iconic Blends & Explainers

Cold Brew Blend —
Built for the Slow Steep

Cold extraction isn't just drip coffee made cold. It's a different process that rewards a different blend — one designed around low temperature, extended time, and what those conditions actually do to sweetness, body, and texture.

Medium-dark to dark Chocolate & brown sugar Low acidity Concentrate-first design 12–24 hour steep
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Why Cold Brew Needs Its Own Blend

Cold water extracts coffee compounds differently than hot water — more slowly, more selectively, and with fundamentally different results. A light, bright blend that's excellent as a pourover will produce a flat, sour, under-extracted mess in a cold steep. A blend built for cold extraction needs to account for these physics from the start:

Cold water extracts slowly — and selectively

Low temperatures mean less extraction efficiency overall. Certain acidic compounds don't extract well in cold water, which is why cold brew tastes naturally smoother. But this also means weaker-flavoured components get lost entirely. You need more of the right compounds from the start.

Acidity reads differently cold

Bright, citric-forward coffees taste pleasantly lively in hot water — but in cold extraction, that same acidity can read as sour or hollow rather than bright. Cold brew rewards coffees with lower natural acidity and more developed sweetness compounds that survive the long, slow steep.

Body becomes the primary texture

Without heat, the "brightness" cues of hot coffee are absent. Body and texture carry the drinking experience — a cold brew that's thin or watery, even if technically correct, feels unsatisfying. The blend needs components that contribute to a full, round, syrupy character at cold temperatures.

Roast depth does more work

A slightly deeper roast brings forward the compounds — caramel, chocolate, malt — that hold up through cold extraction and dilution. Not over-roasted or bitter; calibrated to provide the structure the concentrate format requires when served over ice or with milk.

The Cold Brew Blend principle: every component is chosen for how it performs at low temperature and long contact time — not for how it tastes as a hot cup. This is a purpose-built blend for a fundamentally different extraction process.

The Science

What Cold Extraction Actually Does

Lower chlorogenic acid extraction

Many of the compounds responsible for bitterness and sharp acidity in hot coffee extract poorly at cold temperatures. This is what makes cold brew naturally smooth — but it means the blend must deliver flavour without relying on these compounds.

Sucrose & melanoidin preservation

Cold extraction is gentler on sweetness compounds. Sucrose and melanoidins (roast-developed sweetness) survive the long steep and translate into the smooth, brown-sugar character that defines great cold brew. Roast depth is calibrated to maximise these.

Extended contact time = different balance

12–24 hours of contact extracts differently than 3–4 minutes with hot water. Some compounds that extract quickly in heat barely appear in cold brew; others — body-building lipid compounds especially — have time to fully dissolve, producing the characteristic richness.

The Build

How We Choose Components

Low-acid, high-sweetness Latin American base

Colombia, Brazil, Honduras, or Guatemala lots selected for natural sweetness potential and lower inherent acidity. Provide the chocolate, brown sugar, and caramel backbone. Washed or natural depending on the target flavour profile for the season.

Selective Indonesian or naturals for body

When a natural-processed or low-acid Indonesian lot is available and traceable, it can contribute the full body and earthy-sweet texture that makes cold brew feel rich and satisfying at cold temperatures and high dilution.

Calibrated roast depth

Medium-dark, landed precisely to develop maximum sweetness and body without generating the sharp or ashy bitterness of a dark roast. The target is chocolate, malt, and caramel — not charcoal or smoke.

Seasonal components, consistent promise: The specific origins rotate with fresh harvests, but the flavour target stays constant — rich, smooth, chocolate-forward cold brew with a clean finish and genuine body. Each release lists specific partners and origins on the product page.
Steep Parameters
1:7–1:8
Concentrate Ratio
coffee to water (by weight)
12–24h
Steep Time
cold water, room temp or fridge
Coarse
Grind Size
sea salt texture; very coarse
4–7°C
Serve Temp
fridge cold, over ice
Concentrate Format — Three Ways to Use It

Cold brew is almost always made as a concentrate (higher ratio) and then diluted to serve. This gives flexibility — the same batch can produce multiple different drinks depending on dilution ratio:

Strong Concentrate
1:7

Steep ratio. Produces a rich, intensely flavoured concentrate with full body and deep chocolate notes.

Dilute 1:1 with water to serve straight over ice. Use undiluted as a shot-style base for coffee cocktails or heavily milked drinks.

Best for: cafés, milk drinks, cocktails
Balanced Concentrate
1:8

The everyday home sweet spot. Full flavour at reasonable coffee-to-water use, versatile across most serve formats.

Dilute 1:1 to 1:1.5 with water or oat milk over ice. The starting point for most home cold brew drinkers.

Best for: home daily use, straight over ice
Ready-to-Drink Style
1:12–1:15

Steep straight at a lighter ratio for a cup that's ready to pour directly over ice without additional dilution.

Best enjoyed the same day. Lower caffeine and lighter texture than concentrate — better for casual sipping over a long afternoon.

Best for: casual sipping, lighter preference
In the Cup
Dark Chocolate

The defining note — deep, rich, slightly bitter chocolate that reads as complexity rather than bitterness. The kind of flavour that makes you think "this tastes like a serious cup" rather than "this tastes sweet."

Brown Sugar & Caramel

The sweetness register that makes cold brew drinkable without anything added. Brown sugar, molasses-edge sweetness, caramel — developed through roast and preserved intact by cold extraction's gentleness on sweet compounds.

Syrupy Body

The texture that distinguishes well-made cold brew from cold regular coffee. Full, rounded, slightly viscous at cold temperature — holds up through ice dilution, milk addition, and a long afternoon glass without getting flat or watery.

Smooth, Low-Acid Finish

The absence of sharpness is a feature, not a flaw. Cold extraction's natural gentleness on acidic compounds, combined with components chosen for inherent smoothness, makes for a finish that's clean and inviting without any bite.

Ways to Serve It

Classic Over Ice

Concentrate diluted 1:1 with filtered cold water over a large ice cube. The purest way to taste the blend — chocolate, brown sugar, smooth finish. Nothing added.

Ratio1 part concentrate : 1 part water

With Oat or Dairy Milk

Cold brew's chocolate-caramel character makes it a natural match for milk — the blend was designed to hold up through it without getting lost. Oat milk is the best pairing: it adds sweetness that mirrors the coffee's own without competing.

Ratio1 part concentrate : 1–1.5 parts oat milk

Japanese Iced Style

Steep slightly less time (10–12h) and at a lighter ratio (1:10) for a clean, ready-to-serve style. Pour directly over a large clear ice cube. No dilution needed. A cleaner, lighter-bodied expression of the same blend.

Ratio1:10 steep · pour straight over ice

Affogato-Style Float

Strong concentrate poured over a scoop of vanilla ice cream. The cold brew's chocolate-caramel profile meets the cream in a way that's noticeably better with a purpose-built concentrate than with repurposed drip coffee.

Ratio60–80ml concentrate · 1 scoop ice cream

Nitro Cold Brew

If you're running nitro on tap or using a cream charger whipper at home, this blend is designed with the right body and sweetness for nitrogen infusion. The smooth base picks up the creamy, cascading nitro texture particularly well.

Start with1:7 concentrate before nitrogen charge

In Baking & Cooking

Cold brew concentrate is a natural kitchen ingredient — the chocolate-forward, low-acid profile makes it an excellent flavour addition. Use it undiluted in tiramisu, chocolate cake batter, coffee ice cream, or brownies wherever a recipe calls for espresso or strong coffee.

UseUndiluted concentrate as 1:1 espresso substitute

How to Steep Cold Brew Blend

Cold brew is one of the most forgiving brew methods — no precise temperature control, no timing to the second. What it does require is the right ratio, the right grind, and enough patience. Here's the full framework:

Format Ratio Time Notes
Fridge Steep 1:8 18–24h The safest, most consistent method. Slower extraction at fridge temp (4–6°C) requires more time but produces a cleaner, more stable concentrate. Best for meal-prep batches. Coarse grind — sea salt texture.
Room Temp Steep 1:8 12–15h Faster extraction at room temperature (~20°C). Transfers to the fridge to halt extraction at the 12–15 hour mark. Slightly richer flavour in a shorter window. Coarse grind — monitor carefully; over-extraction is more likely here.
Strong Concentrate 1:7 18–22h fridge For cafés, batch drinks, or if you want to dilute 1:1 to a full glass. Intensely flavoured, rich body. Excellent for milk-based iced drinks where the coffee needs to hold up through the dairy.
RTD Light 1:12–1:15 10–14h fridge Ready-to-drink format — pour straight over ice, no dilution. Lighter caffeine and body; designed for casual afternoon sipping rather than morning fuel. Best consumed same day.

Storage: Strained concentrate keeps in the fridge for up to 2 weeks in a sealed container. Flavour is best in the first 5–7 days. Do not freeze — ice crystal formation damages the extracted compounds and the flavour degrades noticeably on thawing. Full cold brew equipment and recipe guidance is in Bert's Brew Guide.

Cold Brew Blend — Common Questions

Can I use the Cold Brew Blend as a regular hot coffee?
Technically yes — it won't harm you — but it's not the best version of either experience. The medium-dark roast and component selection are optimised for cold extraction: the flavour profile will read as heavier and flatter as a hot pour-over or drip compared to a blend designed for those methods. Use the House Blend or Breakfast Blend for hot brewing and the Cold Brew Blend for what it's built for.
Why is cold brew less acidic than hot coffee?
Two reasons working together: First, cold water extracts fewer of the specific acidic compounds (chlorogenic acids) that contribute to the bright, sharp flavour of hot coffee — the low temperature simply doesn't give those molecules enough energy to dissolve efficiently. Second, this blend is designed with inherently lower-acid components (Latin American lots, controlled roast depth) that reinforce that smoothness. The result is a naturally low-acid cup — not pH-neutral, but noticeably gentler on the palate and stomach.
Does cold brew have more caffeine?
Concentrate has significantly more caffeine per millilitre — because you're using a lot more coffee per unit of water. But when diluted to standard serving strength (1:1 with water), a glass of cold brew has roughly the same caffeine as a comparable hot coffee. The higher caffeine reputation of cold brew comes from serving it undiluted or at concentrate strength, which many cafés do. Ready-to-drink ratios (1:12–1:15) have considerably less caffeine than a standard drip cup.
Can I steep for longer than 24 hours?
We don't recommend it. Beyond 24 hours (especially at room temperature), cold brew begins to over-extract — the pleasant chocolate and sweetness compounds become overwhelmed by harsher, more bitter compounds that cold water does eventually extract given enough time. If you've left it too long and it tastes bitter or hollow, that's why. Strain at 24 hours max and refrigerate. If you need to buy time, transfer to the fridge early — the cold temp slows extraction significantly and gives you more margin.
What grind size should I use?
Very coarse — think sea salt or even coarser. Cold water moves slowly through finely ground coffee and will over-extract very quickly, producing a bitter, murky result. Coarse grinding gives you the right extraction rate for the long steep time. If your cold brew is consistently bitter, go coarser on the grind before adjusting anything else. If it tastes weak and flat after the correct steep time, go slightly less coarse (but still well coarser than drip).
Do I need special equipment?
No — the simplest setup is a large mason jar, a kitchen scale, and a fine mesh strainer or cheesecloth. Combine ground coffee and cold water by weight, stir briefly, cover, and steep. Strain when done. Dedicated cold brew systems (like Toddy or Hario Mizudashi) make straining easier and produce a slightly cleaner cup, but they're not required. The blend does the work; the equipment just holds it while it steeps.