Barley protein content

The protein content in barley grain ranges from 7% to 26% and is measured by the Kjeldahl method using a conversion factor of 6.25. For malting purposes, a range of 9–12% is preferred; levels below 9% impair enzymatic activity, while exceeding the 12% threshold hinders grain modification and negatively affects the organoleptic properties of the beer. For feed use, the highest possible protein levels are preferred.

The level of protein accumulation is determined by the genetic characteristics of the variety and growing conditions. Nitrogen fertilizer application promotes increased protein content, therefore, cultivation of malting varieties requires control of the nitrogen-potassium balance. Elevated temperatures and drought during the grain-filling period trigger a sharp increase in protein concentration, while high yields often correlate with a decrease in protein due to the carbohydrate dilution effect.