How to Make Decaf Cold Brew Coffee
Cold brew is almost always talked about as a summer coffee — the refreshing drink you make when it's too hot for a flat white, or the thing you batch-brew on Sunday and pull from the fridge for the rest of the week. The way most people drink it, it's already an afternoon and evening thing.
Which raises an obvious question that most people don't ask: if you're drinking cold brew at 4pm because you want something cold and coffee-flavoured, why does it need caffeine?
Decaf cold brew isn't a compromise. It's what you make when you've thought about it. This guide covers why, plus everything you need to actually brew it.
Why Decaf Cold Brew Makes Sense
Most of what people enjoy about cold brew coffee has nothing to do with caffeine. The smooth body, the low acidity, the natural sweetness that comes from the long cold steep — none of that comes from the caffeine molecule. It comes from the brew method. Take the caffeine out and the drink is essentially the same.
The argument for decaf cold brew is really an argument about when and why people drink cold brew in the first place. It's rarely the morning cup. It's the afternoon drink, the evening drink, the "I want something cold and coffee-flavoured but I've already had enough caffeine today" drink. Decaf cold brew is purpose-built for exactly that.
The afternoon and evening case
Caffeine has a half-life of around five to six hours in most adults. A regular cold brew at 3pm means meaningful caffeine in your system at 9 or 10pm. Cold brew made with regular coffee beans is often more caffeinated than standard espresso — a 300ml glass of ready-to-drink cold brew can contain 150mg of caffeine or more, depending on the ratio and steep time. That's most of your daily budget in one afternoon glass.
Decaf cold brew made with Swiss Water processed beans contains roughly 2–7mg of caffeine per glass. You can drink it at 5pm and go to bed at 10pm without doing the mental arithmetic. For coffee drinkers who want to keep drinking coffee in the evening — and a lot of people do — this is the point of it.
The flavour argument
Cold brew's slow extraction in cold water pulls sweetness and body from coffee beans more than it pulls acidity and bright aromatic notes. The flavours that come through best are caramel, chocolate, and malt — the same notes that survive the Swiss Water decaffeination process well. Full-bodied, lower-acidity decaf beans suit cold brewing for the same reason they suit the decaffeination process: both reward origins with inherent sweetness and structure rather than delicate floral or fruit notes.
Light roast single origin decaf can taste a bit lost in cold brew — the volatile aromatics that make it interesting as filter coffee disappear in the long steep. Dark roast decaf cold brew can taste heavy, with the roastier notes amplified by the extended brew time. Medium roast is the sweet spot. It has enough body to hold up and enough sweetness to come forward in cold water without tipping into bitterness.
A medium roast Swiss Water decaf — particularly one with caramel and vanilla notes — makes cold brew that's genuinely hard to distinguish from regular cold coffee. The caffeine isn't what you're tasting. The bean is.
Does Decaf Behave Differently in Cold Brew?
Marginally, but not in the way you'd assume.
If you've read our guide to making decaf espresso, you'll know that decaf coffee beans are slightly more porous than regular beans as a result of the decaffeination process. On an espresso machine, this causes the shot to pull faster and can lead to under-extraction if you don't adjust your grind. It's a real consideration.
Cold brew inverts the problem. Cold brewing extracts coffee slowly using cold water over a long period — typically 12 to 18 hours. The low temperature slows extraction dramatically regardless of how porous the bean is. The two effects — increased porosity from decaffeination, reduced extraction rate from cold water — largely cancel each other out. In practice, decaf cold brew behaves very similarly to regular cold brew in the same steep time.
The one adjustment worth knowing: if your decaf cold brew tastes slightly over-extracted at 18 hours (a bit harsh or astringent), try pulling it at 12 to 14 hours next time. It's an occasional issue, not a rule. Most people won't encounter it.
How to Make Decaf Cold Brew
You don't need a dedicated cold brew maker for this. A large mason jar or jug, a coffee grinder, and something to filter through — a coffee filter paper, a piece of cheesecloth, or a fine mesh sieve — is everything you need. The process takes about five minutes of active work. The rest is waiting.
Step 1: Grind coarse
Use a coarse grind — similar to cafetière, or slightly coarser. Cold brewing is forgiving of grind inconsistency, but coarse ground coffee produces a cleaner, less muddy cup than a medium or fine grind because the large particles don't slip through your filter. If you're using a Baratza or Wilfa grinder, set it at the highest or second-highest setting. If you're grinding on a Sage with a burr grinder, use the coarsest filter setting.
For decaf specifically, erring toward the coarser end makes sense. The long steep will extract plenty from large coffee grounds without pushing into over-extraction.
Step 2: Choose your ratio
Two approaches, depending on what you want:
Cold brew concentrate: 100g of ground coffee to 400ml of cold filtered water (1:4 by weight). Steep, filter, then dilute 1:1 with cold water or milk before drinking. Good for iced lattes and for keeping in a smaller container in the fridge. A decaf cold brew concentrate works particularly well as a base for milk drinks — oat milk especially.
Ready-to-drink cold brew: 75g of coffee grounds to 600ml of water (roughly 1:8). Drink straight over ice. More sessionable, lower caffeine per glass, simpler to serve.
For most people making decaf cold brew, the concentrate approach is worth trying — you can dilute to your preferred strength and it takes up less fridge space.
Step 3: Combine and steep
Add the ground coffee to your jar or vessel. Pour cold or room-temperature filtered water over the grounds and stir gently until everything is wet. Cover the jar — a lid, a plate, cling film — and put it in the fridge.
Steep for 12 to 18 hours. Start tasting at 12 hours by spooning a small amount out and trying it. If it tastes smooth and complete, it's done. If it tastes thin, leave it for a few more hours. An hour or two of additional steep time won't ruin a cold brew — it's far more forgiving than espresso or filter.
Room temperature steep: if you want cold brew faster, steep at room temperature for one to two hours instead. The warmer temperature speeds up extraction significantly. Check it at one hour. Room temperature brewing produces a slightly different cup — a bit brighter, slightly more acidic — than cold water brewing.
Step 4: Filter
Pour the steeped cold brew through a coffee filter paper set in a fine mesh sieve over a jug or bowl. A Chemex filter, V60 filter paper, or standard coffee filter paper all work. Cheesecloth works too — fold it over a few times so the weave is tight enough to catch the fine grounds.
Cold brewing takes longer to filter than hot brewing because there's no heat driving the liquid through. Be patient. If it's taking a long time, don't press the grounds — this pushes sediment through and makes the cup muddy. Let gravity do it.
Step 5: Store and serve
Decanted cold brew keeps in a sealed airtight container in the fridge for up to two weeks. Serve over ice, diluted with cold water, or with milk. A cold brew tonic — cold brew poured over ice and topped with tonic water — works well with medium roast decaf if you want a slightly more interesting afternoon drink.
Which Decaf Beans Work Best for Cold Brew?
Roast level
Medium roast is the right call for cold brew, decaf or otherwise. Dark roast cold brew can taste heavy and roasty because the long cold steep draws out more of those darker, more bitter compounds than a hot brew does. Darker roasts aren't bad in cold brew, but they tend to taste one-note. Light roast cold brew loses what makes light roast worth buying — the brightness and delicate aromatics get left behind in the long steep. Medium roast lands between them: body, sweetness, clean finish.
For decaf specifically, this matters more. Light roast decaf has already lost some of its most volatile notes through the decaffeination process. Submitting what's left to a long cold water steep doesn't help. Medium roast decaf holds more in reserve.
Origin
Full-bodied lower-acidity origins — Peru, Brazil, Colombia — are the best decaf coffee beans for cold brew. Their character transfers well to cold water extraction: the sweetness, the caramel and chocolate notes, the round body. High-acidity origins like Ethiopian naturals are more interesting as hot coffee; cold brew flattens their distinctiveness.
Swiss Water vs solvent-based decaf
For cold brew specifically, the decaffeination method matters more than people assume. Solvent-based decaf can carry a subtle flatness — sometimes a very faint chemical edge — that is more detectable in cold brew than in hot coffee or espresso. The reason is that nothing else is masking it: no heat, often no milk, just cold brewed coffee. Swiss Water decaf, which uses no chemical solvents, doesn't have this issue. The bean tastes like the bean.
This isn't a dramatic difference with a decent solvent-processed decaf. But if you're making cold brew specifically because you want to drink large volumes of it over an afternoon, it's worth starting with the cleanest decaf you can find.
How Much Caffeine Is in Decaf Cold Brew?
Less than you might think, even by decaf standards.
Swiss Water processed decaf contains approximately 2–5mg of caffeine per cup in a standard hot brew. Decaf cold brew made at a ready-to-drink ratio (1:8) produces a similar range — roughly 2–7mg per 300ml glass, depending on steep time and exact ratio.
Cold brew concentrate before dilution is more concentrated: around 4–10mg per 100ml. After diluting 1:1, you're back to the ready-to-drink range.
For context, regular cold brew concentrate can contain 150–200mg of caffeine per 100ml before dilution. Decaf cold brew concentrate is somewhere around 95–98% lower.
For anyone tracking caffeine intake during pregnancy, the NHS recommends a maximum of 200mg from all sources per day. A large glass of decaf cold brew moves that number by about 5–7mg. You can drink it freely alongside tea, filter coffee in the morning, or whatever else you have across the day without the mental arithmetic.
Simmer Down Decaf in Cold Brew
We've been making Simmer Down as a cold brew for a while. The Peru Cajamarca origin — Bourbon and Typica varietals, washed process — suits cold water extraction well. The vanilla fudge and caramelised biscuit profile that's evident as espresso comes forward cleanly in cold brew too. At 12 hours in the fridge at a 1:8 ratio, it produces a cold brew coffee that's smooth, sweet, and clean-finishing without any of the flatness you sometimes get from lesser decaf.
With oat milk at a 1:1 concentrate dilution, it's one of the better iced lattes we've made. Great Taste awarded — and the judges scored it without knowing it was decaf, which is the most relevant endorsement we can think of for a guide that's essentially arguing decaf cold brew tastes like coffee.
Available whole bean (grind fresh before brewing for the cleanest cup) or coarse ground at checkout if you're ordering specifically for cold brewing.
If you want some caffeine — enough to notice, not enough to keep you up — Simmer Down 50% Decaf is the same bean as a half caff blend. Cold brew made with the 50% version sits at roughly 30–50mg per glass before dilution. A reasonable middle ground if you're cutting back rather than cutting out.
Frequently Asked Questions
Can you make cold brew with decaf coffee beans?
Yes. Decaf coffee beans work well for cold brew and require minimal adjustment from your standard process. Use a coarse grind, steep for 12–18 hours in the fridge, and filter as usual. The long, cold steep is actually the most forgiving brew method for decaf — the low extraction temperature compensates for the slight porosity increase that comes from decaffeination.
Does decaf cold brew taste different to regular cold brew?
With a good quality Swiss Water decaf, not noticeably. Cold brew's slow extraction accentuates sweetness and body rather than brightness or delicate aromatics — and those are the attributes that decaffeination preserves best. A medium roast Swiss Water decaf produces cold brew that tastes like cold brew. The caffeine is absent. The flavour isn't.
How long should I steep decaf beans for cold brew?
12 to 18 hours in the fridge is the standard range. Start tasting at 12 hours. Decaf beans are marginally more porous than regular beans, so on occasion they extract slightly faster — if the cold brew tastes over-extracted at 18 hours, start pulling it at 12 to 14 hours next time. It's not a common issue, but worth knowing.
What grind size should I use for decaf cold brew?
Coarse — similar to cafetière, or slightly coarser. Coarse ground coffee produces a cleaner cup with less sediment and is less likely to over-extract in a long steep. For decaf specifically, the coarser end of the range is sensible. A long cold water steep will extract plenty from large particles without pushing into bitterness.
Can I make cold brew concentrate with decaf?
Yes. Use a 1:4 ratio by weight — 100g of ground decaf coffee to 400ml of cold filtered water. Steep for 12 to 18 hours, filter, and dilute 1:1 before drinking. Decaf cold brew concentrate works well as an iced latte base. Diluted with oat milk and poured over ice, it tastes like a proper café iced coffee. The caffeine per glass after dilution is around 2–5mg.
How much caffeine is in decaf cold brew?
Very little. A glass of ready-to-drink decaf cold brew (1:8 ratio, 300ml) contains roughly 2–7mg of caffeine. Decaf cold brew concentrate before dilution contains around 4–10mg per 100ml. Both are well within the NHS recommended limit of 200mg per day, including for pregnant women who are monitoring their caffeine consumption carefully.
Is it worth making decaf cold brew at home?
Yes, especially if you want to keep drinking coffee in the afternoon or evening. A batch takes five minutes of active time, keeps for two weeks in an airtight container in the fridge, and produces something that genuinely tastes like cold brew coffee — not a reduced version of it. The effort is the same as regular cold brew. The payoff is a drink you can have at any hour without thinking twice about it.
