Comparison of the Degree of Hydrolytic and Cytolytic Modification in Wheat Malts Obtained from Grain of Selected Wheat Cultivars Produced at Different Levels of Nitrogen Fertilisation

The degree of hydrolytic modification (marked by parameters: extractive capacity, diastatic power and degree of fermentation) in wheat malts significantly influences their quality, determining their potential for use in brewing. Nitrogen fertilisation at a dose of 60 kg N·ha^-1 applied in 3-year field experiments had a positive effect on the extractability value of wheat malts, with an average value of 84.51% d.m. The value of diastatic power in the obtained malts, depending on the variety, was on average at the level of 334-414 units W-K (Windisch-Kolbach) and 357-380 units W-K, depending on nitrogen fertilisation. Wort attenuation obtained from the analysed wheat malts was at a similar level (on average 78.1%), except for malt obtained from grain of wheat fertilised with a nitrogen dose of 40 kg N·ha^-1, for which significantly lower values were obtained (respectively, by 5.12%). The viscosity parameter of wheat malts, determining the degree of cytolytic modification, varied and averaged 1.95 mPa·s for the variety and for the nitrogen fertilisation applied. In 2-year canopy experiments, at a nitrogen fertilisation level of 60 kg N·ha^-1, the Elixer cultivar was characterised by the best indicators of the degree of hydrolytic and cytolytic modification.