Half caf is the bit of the coffee aisle that nobody quite explains. You can find it on roaster websites, on the menu at independent cafes, occasionally in a supermarket. Almost nobody tells you what it actually is, or what makes one bag worth buying and another one not.
Half caf coffee, sometimes written half caff, is a blend of 50% regular coffee and 50% decaffeinated coffee. It delivers around 40 to 70mg of caffeine per 8oz cup, against 80 to 120mg for full-strength and 2 to 15mg for decaf. Roasters can pre-blend it. You can also mix your own at home, which is cheaper and gives you control over the decaf method. It’s a sensible middle ground for anyone reducing caffeine, extending an afternoon cup, or testing whether they actually mind the taste of decaf.
The part nobody else covers, and the part that matters most, is the decaf half. A half caf blend is only as good as the decaf inside it. Most articles on this topic are written by roasters selling their own blend. This one isn’t.
What is half caf coffee
A 50/50 blend of caffeinated and decaffeinated coffee beans. The ratio is by weight, not volume. Both spellings, half caf and half caff, are in active use, and Google’s own autocorrect will swap between them depending on the query. There is no consensus on which is correct. We have settled on half caf because it matches the way most UK roasters label the product.
Other terms you’ll see for the same thing: half caffeine coffee, 50/50 blend, reduced caffeine coffee, low-caf. They all mean the same drink.
Half caf can be made two ways. A roaster blends two coffees, usually after roasting them separately so each component hits its own ideal roast curve. Or you do it yourself at home with two bags from the shelf. The roaster version is more consistent, since the recipe stays the same each batch. The home version is cheaper and lets you choose the decaf method, which, as we’ll see, is the part that matters.
Half caf is distinct from naturally low-caffeine varieties like Laurina. Laurina is a real coffee species with roughly half the caffeine of Arabica, but it’s commercially rare and not what you’re buying when you order half caf.
Half caf vs decaf, how they differ
The shorthand: half caf still has meaningful caffeine. Decaf has trace amounts only.
| Half caf (8oz) | Decaf (8oz) | Regular (8oz) | |
|---|---|---|---|
| Caffeine per cup | 40 to 70mg | 2 to 15mg | 80 to 120mg |
| Caffeine removed | About 50% | 97% to 99.9% | None |
| Caffeine in espresso shot | 30 to 50mg | 2 to 5mg | 63 to 95mg |
| Method transparency | Depends on the decaf component | Usually visible on packaging | N/A |
| Taste vs regular | Close, if the decaf is quality | Slight loss of volatile aromatics | Baseline |
EU and UK decaf regulation requires 0.1% caffeine or less of roasted coffee dry matter; the limit for soluble and extract products is 0.3%. The US standard is 97% removal. Either way, decaf is not zero. The full picture on residual caffeine sits at how much caffeine is in decaf coffee.
The practical implication is bedtime. Caffeine has a half-life of approximately five hours in most adults, though individual variation means the range runs from around three to seven hours. A 3pm cup of regular coffee at 100mg still has around 50mg circulating at 9pm. A 3pm half caf cup at 50mg leaves around 25mg. Not zero, but meaningfully less. If you want closer to zero, you want decaf. If you want a real caffeine hit at 11am and something more forgiving at 3pm, you want half caf.
How much caffeine is in a cup of half caf
A standard 8oz cup of half caf coffee contains around 40 to 70mg of caffeine. Most product testing clusters at the lower end, around 40 to 50mg. The upper end of the range, towards 70mg, accounts for blends with a Robusta-heavy caffeinated component or unusually strong brews.
A few real reference points. WBRoast reports half caf espresso shots at 30 to 50mg per shot. Volcanica Coffee measures their half caf at roughly 47mg per 8oz. UK pod brand Crukafe lists their half caff pod at a maximum of 35mg.
Four variables move the figure:
- Bean variety. Robusta contains roughly double the caffeine of Arabica. A half caf blend using a Robusta-heavy base hits the upper end.
- Roast level. Any caffeine difference between light and dark roasts is negligibly small by weight at commercial roast temperatures; the practical effect on a cup is minimal.
- Brew method. Espresso is more concentrated by volume but smaller in total serving. An 8oz filter brew tends to deliver more total caffeine than a single espresso shot of the same blend.
- Ratio precision. A pre-blended product is consistent batch to batch. A home blend mixed by scoop varies because bean density varies. Weighing fixes that.
For context: EFSA and the FDA put the upper safe limit for healthy adults at 400mg of caffeine per day. A half caf cup is well inside that, even at the upper end of the range.
Who half caf is for (and who it isn’t)
Four practical use cases.
Gradual caffeine reducers. Going from regular coffee straight to decaf is a 95% caffeine drop, which is enough to cause withdrawal headaches in regular drinkers. Half caf is a 50% drop. A stepping-stone pattern of two to four weeks on half caf before fully switching to decaf is a kinder route. We covered the broader move in switching to decaf.
Afternoon coffee drinkers. The most useful use case and the most underserved one. Caffeine half-life means an afternoon regular coffee can still be active at bedtime. Half caf in the afternoon gives you the ritual and a meaningful caffeine bump without the same evening cost.
Caffeine sensitivity. Some people get palpitations, anxiety or jitters at 200mg of caffeine, well inside the EFSA recommended daily limit. A 40 to 70mg half caf cup sits at the low end of meaningful caffeine. Enough to feel something. Not enough to feel too much.
Decaf sceptics. Anyone who suspects decaf “tastes different” can use half caf to test the water. The caffeinated half does most of the flavour heavy lifting, which means a quality decaf component is less exposed. If you like the half caf, the jump to full decaf gets easier.
Who half caf is not really for. Pregnancy: NHS guidance is a 200mg daily caffeine limit and the practical steer is to go as low as possible, not to aim for the limit. A 70mg half caf cup uses more than a third of the day’s allowance. For pregnancy specifically, we’d point you at decaf during pregnancy rather than half caf. And anyone avoiding caffeine for a specific medical reason (arrhythmia, certain medications, severe anxiety) should treat half caf as “caffeine reduced”, not “caffeine free”, because that is what it is.
What makes a good half caf blend
The decaf component, not the caffeinated half, determines whether a half caf blend is any good. The caffeinated coffee is half of the cup, so the decaf is the other half. A flat or off-tasting decaf does not disappear in a blend. It contributes its faults to every cup.
There are four mainstream decaf methods, and they vary considerably in flavour outcome.
| Method | Solvent | Flavour outcome | Notes |
|---|---|---|---|
| Swiss Water | None, water and carbon only | Clean, chocolate-leaning, some loss of volatiles | UK specialty default. Used by Bad Hand Coffee and others |
| Sugar cane (EA) | Ethyl acetate, naturally derived | Slight sweetness boost, fruity notes | Common from Colombia. Popular among UK specialty roasters |
| CO2 | Pressurised CO2 | Strong body and lipid retention. Espresso-friendly | Specialty grade but rarer in UK retail |
| Methylene chloride | Chemical solvent | Variable, can taste hollow in poor blends | Cheapest. Avoided by most UK specialty roasters |
The transparency test is simple. If a roaster advertises a half caf blend without saying what decaf method the decaf component uses, it’s usually methylene chloride. Roasters using Swiss Water, sugar cane ethyl acetate or CO2 are typically proud to say so. Look for the method on the bag or the product page. If it’s not there, ask.
The flavour-difference question gets a calmer answer than you’d think. A well-matched half caf with quality decaf has a marginally lighter mouthfeel than regular coffee because decaffeinated beans are slightly more porous. That’s the most you’ll notice. With a poor decaf component the gap widens fast.
Half caf in the UK, what to buy or make
Two routes. Buy a pre-blended bag from a UK specialty roaster. Or mix your own from anything in the decaf directory.
Pre-blended from UK roasters
Five UK roasters currently selling half caf, with the decaf method confirmed where we could verify it.
- Ozone Coffee. Half Caff. A 50/50 of Brazilian sugar cane decaf and washed El Salvador. Tasting notes: milk chocolate, brown sugar, biscuit.
- Doe and Fawn. Half Caf. A Colombian decaf paired with washed Colombian. Notes: milk chocolate, blood orange, tonka bean.
- Calm Coffee Roastery (Peckham). Half Caf Calm Darker Blend. A darker roast with almond, caramel and dark chocolate notes, from a roastery that specialises in low caffeine coffee. Component origins are not listed, so check with them if origin matters to you.
- Bad Hand Coffee (Bournemouth). Half Caf Low Caffeine Blend. Colombian and Peruvian, Swiss Water decaf.
- Cworks. Multiple flavoured half caf blends, including Toffee and Caramel, Apple Pie and Custard, and Chocolate Fudge Cake. Check the product page for the decaf method used in each blend.
Doe and Fawn, Ozone and Calm are the ones we’d point at first if you want a quality decaf half without thinking about it. Bad Hand is the Swiss Water pick.
Make your own
This is the genuinely useful route and the one nobody covers. Any specialty decaf plus any regular coffee you already drink equals half caf. The concept is straightforward; the only thing that goes wrong is the ratio.
- Pick a decaf you’d happily drink on its own. Swiss Water or sugar cane ethyl acetate. Anything in the Decaffeinate directory qualifies, since the whole catalogue is specialty.
- Pick a regular coffee with a complementary profile. Same origin region is the safe play. A Colombian decaf pairs naturally with a Colombian washed coffee.
- Weigh, don’t scoop. A 1:1 ratio by weight on a kitchen scale beats a 1:1 ratio by scoop, because bean density and roast colour change the scoop weight.
- Combine whole beans in a sealed container. Whole bean works better than pre-ground. Pre-ground oxidises faster and blends unevenly.
- Shake before grinding. Beans settle by density. A quick shake before scooping into the grinder keeps the ratio honest.
- Brew as normal. No special equipment or technique required.
Home blending is cheaper than buying a pre-mixed bag, and it gives you full control over the decaf method. It also means you can use a coffee you already like as the caffeinated half.
If you’re blending at home, the decaf you pick is doing half of the work. Browse the directory for Swiss Water and sugar cane decafs from UK specialty roasters. Any of them works as the decaf half of a home blend.
If you want one new specialty decaf recommendation a fortnight, including half caf pairing ideas as they come up, the Decaffeinate Club covers it.