COSTA Coffee has been blasted for “tricking” customers into paying an extra 25p.

The chain, recently bought by Coca-Cola for £3.9billion, is pushing its Winter Character Roast.

But staff fail to mention that the Columbia blend — made with “winter berries, dark cocoa and warming cinnamon’” — adds nearly 11 per cent to the cost.

The Sun tested the ruse at a South London branch.

Ordering a small white Americano, we were asked: “Would you like that with a Columbia roast?

“We have two blends of coffee. This one is 100 per cent Arabica. It has a fruity taste and is a little bit less bitter.”

But no mention was made of the 25p extra charge, taking the price from £2.30 to £2.55.

Martyn James, of consumer complaint handling site Resolver, said: “It’s upselling by stealth.

ESPRESSO has compounds that can slow prostate cancer growth — but they are often stripped out in filtering coffee, Japan’s Kanazawa University said after tests on mice.

“If Costa wants to try out a new blend of coffee beans it should be upfront about it.

“I’ve fallen victim to this pressure tactic at Costa.

"It leaves a bitter taste in the mouth.”

Costa told The Sun that staff were expected to warn of the 25p charge.

It added: “We apologise to any customer who has opted for a new roast without being informed of the additional cost.”