Decaf Coffee Explained: How It's Made and How to Brew It

What is decaf coffee?

Decaf is coffee with most of its caffeine removed. The caffeine comes out while the beans are still green, before roasting, so decaf beans are roasted and brewed like any other coffee.

Decaf starts as ordinary green coffee, grown on the same farms as regular coffee. What changes is a soak at a decaffeination plant before the beans are shipped to the roaster, and a little extra care in the roast.

Does decaf coffee have caffeine?

Yes, a small amount. Decaffeination usually removes around 97% or more of the caffeine, so a cup of decaf still carries a few milligrams. Decaf is low-caffeine coffee rather than caffeine-free coffee.

The exact amount varies with the bean and the process, as well as how much coffee goes into your cup. The standard a decaf has to meet also differs from country to country.

How is decaf coffee made?

Every method soaks or steams green coffee so the caffeine can move out of the bean, then removes it with water and carbon filters, with a solvent made from sugarcane, or with pressurised carbon dioxide. The beans are then dried and sent to the roaster.

What is the Swiss Water Process?

The Swiss Water Process uses water and carbon filters, with no solvents. Green beans soak in hot water until their caffeine and flavour compounds dissolve. The water then runs through activated carbon that traps the caffeine, leaving water with no caffeine that is already full of the coffee's flavour compounds.

The next batch of green beans soaks in that flavour-rich water. Because the water already holds the flavour compounds, it is mostly caffeine that moves out of the new beans, and the cycle continues until they reach the target caffeine level. Despite the name, the process runs in Canada today.

What is sugarcane decaf?

Sugarcane decaf, also called ethyl acetate or EA decaf, uses a solvent made from fermented sugarcane. The green beans are moistened with water and washed with ethyl acetate, which bonds with the caffeine and carries it out. Steaming then removes the remaining ethyl acetate before the beans are dried.

Much of it is processed in Colombia, close to both the coffee and the sugarcane. It often keeps a sweet, fruity character, and our own decaf, further down this page, is made this way.

What is CO2 decaf?

CO2 decaf uses carbon dioxide under very high pressure, in a state between a gas and a liquid, as the solvent. Moistened green beans sit in a sealed steel vessel while the CO2 circulates, picking up caffeine and leaving most of the flavour compounds behind.

The CO2 then passes through water or carbon filters that strip out the caffeine, and goes back into the vessel for another round. The method suits large volumes and tends to keep the bean's body and sweetness.

What does decaf coffee taste like?

Good decaf tastes like the coffee it came from, with softer acidity and a rounder body. Old or poorly processed decaf tastes flat and papery, and that is where decaf's reputation comes from.

Decaffeination changes the bean before it reaches the roaster. Decaf green beans are darker and more fragile than regular green coffee, so they roast faster and need gentler handling. Age matters too. Decaf sells more slowly than regular coffee, so it can sit on a shelf for months, and stale decaf loses what flavour the process left behind.

The process leaves its own mark. Sugarcane decaf often tastes sweet and fruity, Swiss Water decaf tends to taste clean and gentle, and CO2 decaf usually keeps a fuller body.

How do you brew decaf coffee?

Brew decaf with the same recipes as regular coffee, starting from an 18g dose. Decaf beans are more porous after processing, so for filter, grind a step coarser if the cup tastes bitter or dry, and for espresso, expect to grind finer because shots tend to run quicker.

• Pour-over: 18g of coffee to 260g of water at 93°C, finishing in 2:30 to 3:00.
• French press: 18g to 270g of water at 93°C, 4 minutes, then press.
• Espresso: 18g in and about 36g out in 25 to 35 seconds. Our home espresso guide covers dialling in.
• Drip bag: 200ml of water at 95°C, poured slowly, ready in 2 to 3 minutes.

Decaf beans tend to fade faster once the bag is open, so buy smaller amounts and keep the bag sealed and out of sunlight. Like any coffee, it drinks well from about 7 to 30 days after its roast date. If water temperature is new to you, our water guide sets it by roast level, and our guide to grind size and brew time shows how to adjust a recipe.

Can you use decaf for cold brew and milk drinks?

Yes. Decaf works in every brewing method, so use the same ratios you would for regular coffee. A medium or medium-dark decaf with chocolate or caramel notes holds up well under milk and in cold water.

For cold brew, steep 18g of coarse decaf in 150ml of cold water in the fridge for 18 to 24 hours, then filter and dilute 1:1, as our cold brew guide explains. For a decaf latte, pull an 18g shot and add steamed milk as usual. Decaf shots can run fast, so check your grind before blaming the beans.

Does Bean Shipper sell decaf?

Yes. Our decaf is the Colombia Wuchii sugarcane decaf drip pack, a medium roast with passion fruit and sugarcane notes, at RM30 for a box of six drip bags. It is roasted to order in Kuala Lumpur and ships within 24 hours of roasting.

The coffee is grown by small producers around Inzá in Cauca, Colombia, at up to 2,100 metres, washed, then decaffeinated with ethyl acetate from sugarcane. Each bag makes one cup of about 200ml: hang it on your mug, pour 200ml of water at 95°C and it is ready in 2 to 3 minutes.