Summary of the Brewing Research
International report of
Pesticide Evaluation.

Malting Trials with barleys treated with Demeter

Introduction

The object of the trial was to determine whether the treatment of barley during with DEMETER has any deleterious effect on malting, or on the quality of the final malt.

The trials involved malting, on the pilot scale (50 kg), barleys treated with DEMETER in a similar manner to that recommended by the manufacturers and at an overall rate which was around the maximum recommended application rate. Process performance and malt quality were then compared with those of a batch of the same barley, which had not been treated with DEMETER. The quality of each malt was then assessed by analysis for a range of quality parameters, using standard industry methods for which BRi is accredited under the UKAS accreditation scheme. Samples of malt rootlets (which may be used for animal feed) were analysed for ash content by a subcontractor.

Method

A BRi stock barley, Optic barley from the 2002 harvest, was used for these trials. One portion was treated with DEMETER. The DEMETER was applied to grain contained in a plastic storage bin with a cross sectional area of 0.32 m2. The DEMETER was applied at a rate of 10g /layer. This dose rate is around the maximum dose recommended by the manufacturers (10-30g/m2). Four layers were treated with the DEMETER, with 18cm of untreated grain between each layer. The overall bed depth was 0.54m. The overall dose rate was 40g/136kg of barley. A control using the same barley but no DEMETER was set up in a similar storage bin. The two bins were stored at ambient temperature (20 -30?C) in the malting block at BRi for one month.

The control and treated barleys were malted on the pilot scale to produce lager malts. Samples were withdrawn daily to check the rate and extent of germination. No significant differences were observed between the control and test batches in malting performance, germination or malt yield.

The roots were removed from the finished malts. The malts were then analysed for a number of quality parameters using standard industry methods. The rootlets were analysed for total ash. No analytical differences were observed between the control and the test malts. Control and test rootlets were very similar in ash content.

Result

These trials indicate that treatment of barley with DEMETER during storage has no detectable effect on the malting performance nor on the quality of the malt for brewing.

Conclusion

In these trials, treatment of malting barley during storage with DEMETER at an application rate which was higher than the manufacturers recommended level have no significant effect on barley germination, malting performance, or malt quality for brewing.