A cup of coffee is becoming an increasingly luxurious treat as wholesale prices soar to their highest levels in a decade, leading companies and coffee chains to put prices up with unprecedented speed.

Procter & Gamble, the owner of the US's Folgers brand, and Kraft, the owner of Maxwell House and Yuban, have increased the price at which they sell coffee to retailers three times in the past six months. Kraft Foods has also been taking prices up in Europe.