23 June 1995

Maize versus wheat

IDENTIFYING suitable wheat varieties for distilling will protect vital markets for Scottish growers from foreign competition.

Over half the Scottish wheat crop – 500,000t – was used for grain whisky production this year, says Heriot-Watts Universitys Ian Tillett. But maize is easier to use. Only lower costs are keeping the wheat market alive, he warns.

"Maize yields more spirit and is easier to process. But it costs 29p/litre compared with wheat at 27p/litre. If the wheat price rises, distillers will switch. It is big business – they have no conscience about Scottish farmers."

Suitable replacements need to be found for the main distilling variety Riband. To speed the process H-GCA-funded work is examining Ribands success. It produces 442 litres/t of spirit, 9 litres/t more than Mercia and 14 litres/t more than Admiral. "That may not sound much, but when you are producing 200m litres of alcohol a year it soon adds up."

It appears Ribands softer protein mesh holds starch granules less strongly, allowing easier enzyme action. Hard or high nitrogen wheats resist this more, and produce more foam, causing problems in processing. Spent hard grains used for animal feed are also wetter and stickier, raising costs for wet grains transport and dried pellet manufacturing.

To protect todays markets growers must supply pure Riband, says Mr Tillett. "It is tempting to include the odd bit of failed milling wheat. But even 10% inclusion will cause big problems."

Consort and Encore will be tested this summer. &#42