Fresh blackcurrants and products such as blackcurrant cordials and jams could become more expensive following poor harvests in Europe and New Zealand, which have put a squeeze on supplies.

The price of blackcurrant concentrate used in processed products has more than doubled since the beginning of 2011, soaring by 118% from about £3,600/tonne to just under £8,000/tonne now [Mintec].

Meanwhile the wholesale price of fresh blackcurrants, which fluctuates greatly through the year, stood at £5,400/tonne in the UK in August, up 12.5% year-on-year.

Poor harvests in key growing seasons are largely to blame. New Zealand's harvest at the start of the year came in below expectations after a lot of fruit was damaged by sun and wind, while frosts in Poland reduced crops and caused supply shortages in the summer. Global stocks were already low as a result of poor crops in Northern Europe in 2010, said Mintec analyst Robert Miles. "There has also been increased demand because of the perceived health benefits," he added.

Most UK blackcurrants go into Ribena on a fixed contract but growers have been able to sell the remainder at very good prices because of supply shortages in Europe and rising interest in blackcurrant products in the UK and abroad.

Jo Hilditch of the Blackcurrant Foundation, which grows currants for Ribena, said that although higher wholesale prices were likely to be passed on to consumers for many products, this was not likely for Ribena. "Because blackcurrants for Ribena are grown to contract, they are a bit more insulated from price rises," she said. "Plus, the actual cost of the blackcurrants in the final product isn't that high compared with marketing costs etc. Even if our contract price with Ribena went up, it wouldn't really affect the retail price."

At present, a one-litre bottle of Ribena Original squash costs an average of £2.60 across the mults about the same as this time last year [].