A government-funded report that implied farmers were increasing the water content of tubers in order to squeeze more money out of buyers has been dismissed by the industry as “naïve” and “illogical”.
The report by The Carbon Trust, which works with companies to reduce emissions, is thought to have embarrassed senior executives at Walkers Snack Foods, which allowed its crisp supply chain to be used as a case study. The company has refused to comment on the report, which the National Farmers Union described as “factually incorrect”.
Carbon Footprints in the Supply Chain: The Next Step for Business was hailed as a major new initiative in cutting emissions and driving out costs by looking at the whole supply chain for a number of products, including crisps.
It claimed that Walkers, which uses 350,000t of home-grown potatoes a year, wasted millions of pounds and caused unnecessary pollution by frying moisture off potatoes that farmers had kept in humidified stores to deliberately boost their water content. It said “humidified atmosphere increases their weight and so also their value” and called for a review of the way potatoes were traded.
But the British Potato Council called the report “naïve”. Water content was determined by potato variety and climate during the growing season and could not be increased in store, a spokesman said. Far from boosting water content, humidifiers prevented water loss, shrinkage and compression, which could cause the crop to be rejected by manufacturers. The idea that humidifiers increased emissions and energy consumption was Illogical, he said.
“One of the reasons you go to humidified storage is because you can run the ventilation system at slower speeds and consume a lot less energy.”
But the report’s author, senor strategy manager at The Carbon Trust, Ewan Murray, defended the findings, saying they had been misinterpreted.
“We spent a lot of time with Walkers’ purchasing team and its potato farmers. We understand that if you squeeze all the water out of a potato you end up with not a very good product and we need to make sure that quality is not sacrificed to reduce carbon emissions. But Walkers specify 21% - 24% dry matter (DM) content [in potatoes] and what we discovered was that within that band there’s quite a degree of difference in extra energy that Walkers ultimately consumes.
“If Walkers can, in collaboration with farmers, change the way that DM range is hit, so more of the product comes in to the sheds closer to 24%, then there’s less need to humidify and also less need for Walkers to drive that water off.”