The price of the ubiquitous smoothie is set to rocket this autumn, as manufacturers struggle to recover rising fruit costs.

Squash prices are also expected to rise, after a disastrous fruit crop in Eastern Europe left blackcurrants up to five times more expensive than last year and strawberries, raspberries and blackcurrants up to 100% more expensive.

"Working off prices for this season's crop, we need a price increase on smoothies of about 15%," said Adrian Barber, purchasing manager at own label smoothie maker The Serious Food Company.

"Price discussions are going on now with the retailers, but one of them needs to take a lead."

Even bigger increases could be on the way for fruit squashes, according to Princes. Soft drinks purchasing manager David Mitchell said he would be paying five times more for blackcurrants in October than in autumn 2006, while strawberries and raspberries had doubled in price.

"We've paid the price to get the fruit, but others may struggle," he said. "On blackcurrant squash, we need an increase of as much as 50p per litre."

If that rise were passed through to consumers, it would add about 50% to retail prices for juices. A 15% increase on a Tesco own label smoothie would push the price from £1.44 per litre to £1.65, while an Innocent drink would jump from £2.99 per litre to £3.44.

Both companies said retail prices rises were unlikely to dent the number of units sold. "These products are undervalued anyway," said Barber. "For the amount of fruit that goes into each drink, they're still good value."

The supply problems are strongest in Poland, where crops were decimated by an unseasonably late frost in May, slashing yields and driving some farmers to suicide. Besides berries, the apple harvest is expected to come up short, leading to higher prices in October.