Costa Smooth Decaf Blend Instant: How the Decaf Works

Costa Coffee Smooth Decaf Blend: the after-dinner jar, in summary: A soft, low-bitterness decaf instant in a 190g jar, made for coffee after dark. It is decaffeinated rather than caffeine free, a shade lighter than its caffeinated sibling, and good for roughly 105 mugs at a rounded teaspoon.

Last reviewed by the teas.co.uk team in September 2026.

Decaffeination happens to the green bean before it is ever roasted, and that early step shapes everything you taste in this jar. What comes out the other end is a mild, gently toasted instant for the mug after the evening meal, when a caffeinated cup would be a poor idea.

Where the caffeine goes

Caffeine comes out of the green coffee well before the roaster gets it, and three routes are in common use. One soaks the beans in water and catches the caffeine in a carbon filter. Another pushes carbon dioxide through them under pressure, which picks out the caffeine and leaves most of the flavour alone. The third rinses them in a regulated food-grade solvent, which is taken off again before the roast.

Every one of those methods leaves a small residue behind, which is why the word on the jar is decaffeinated and never caffeine free. Which route this blend takes is not something we can confirm, so read the current pack if it matters to you. For most people an evening mug of this is nothing like a caffeinated one, but anyone told to avoid caffeine entirely should treat the trace as real.

How it compares with the caffeinated Costa jar

Costa's Smooth Medium Blend, which we also stock in the same 190g size, is this blend with the caffeine left in. Taste the two together and the caffeinated one has a little extra weight and presence, while the decaf comes across lighter and softer: warm and lightly toasted, never dark, with very little bitterness. In a mug with milk, most people would struggle to tell them apart.

That makes the pair useful for a household that drinks coffee all day: the caffeinated jar for the morning, this one after the evening meal, or this one for whoever says coffee keeps them up. Instant has already traded some aroma for speed, so removing the caffeine costs it less than it would cost a bag of whole beans, which is why the gap between the two jars is so narrow.

Getting a fuller decaf mug

One rounded teaspoon is about 1.8g, and at that measure the jar runs to roughly 105 mugs. Many decaf drinkers go a little heavier on the spoon, because the cup starts out a shade lighter, and that is a sensible adjustment. Use water just off the boil rather than at a rolling boil, stir right to the bottom and add any milk last. Nothing is needed beyond the kettle.

Soft, low-bitterness coffee wants a biscuit with some sweetness and chocolate rather than anything sharp. A milk chocolate digestive is the obvious partner and takes a quick dunk in a milky mug, and plain buttery Danish cookies suit it too. What it will not do is stand up to very dark, bitter chocolate, which tends to make a mild decaf taste thin by comparison.

The packs we stock

Costa Coffee Smooth Decaf Blend Instant Coffee, 190g (barcode 5039303008418)

What to eat with it

McVitie's Digestives Milk Chocolate Biscuits, 433g: a milk chocolate digestive is the classic partner for a mild, milky decaf, and the big pack suits a nightly habit.
Royal Dansk Danish Butter Cookies, 340g: plain butter cookies match the soft, toasted finish without overpowering it.
Oreo Vanilla Cookie Chocolate Sandwich Biscuit Twin Pack, 2 x 154g: a chocolate and vanilla sandwich biscuit gives a sweeter contrast for anyone who takes their decaf black.

Elsewhere in the Costa range

The full range is on the Costa brand page.

FAQ

Is Costa Smooth Decaf Blend completely caffeine free? No. Decaffeination removes most of the caffeine but always leaves a trace, so the jar says decaffeinated; if you need to avoid caffeine entirely, read the current pack.

Which decaffeination method does Costa use for this blend? The information we hold does not name it. Water with a carbon filter, pressurised carbon dioxide and a food-grade solvent are the usual routes, so check the current jar for any detail Costa gives.

Can I tell it apart from the caffeinated Smooth Medium Blend? Side by side, the decaf is a little lighter and softer. With milk in, most people cannot.

How many mugs does the 190g jar make? Roughly 105 at a rounded teaspoon of about 1.8g; a generous spoon brings that number down.

What is the best biscuit with decaf instant coffee? Something sweet and chocolatey, such as a milk chocolate digestive. Very dark chocolate can make a mild decaf taste thin.

Curator's note: Make this the after-dinner jar. Be a little generous with the spoon, let the kettle settle first, and it does the job without any fuss. Lee, teas.co.uk, Tunbridge Wells.

In short: Costa Coffee Smooth Decaf Blend: the after-dinner jar

Field	Detail
Brand	Costa
Packs we stock	190g
Category	Instant Coffee
Caffeine	decaffeinated
Best time	After the evening meal
Spoon	Rounded, or slightly heaped
Best with	A milk chocolate digestive