###### Abstract  
The use of purpose-selected wheat in brewing is limited because it is either not suitable for the application of usual agrotechnical measures or, more often, is not adapted to specific climatic conditions. As unmalted wheat in brewing can cause process problems and problems with the quality composition of mash/wort and consequently beer, by using the appropriate type and variety, but also by adjusting the malting process, these problems can be completely avoided or significantly reduced at the start. Two varieties were selected for the research, which in previous research showed good brewing/malting properties and which have significantly different starting values for the share of total protein (TP) in the grain. The goal of this research was to determine the effect of grain milling granulation on the quality of mash obtained from a hard type of wheat, i.e., the changes in the fermentable and non-fermentable extract ratio during mashing. Varieties with higher and lower initial contents of total protein (TP) in the grain were tested. It was found that regardless of the initial difference in TP concentration, the concentrations of total soluble proteins (TSP) and high molecular protein fraction (HMW N) are similar for varieties with higher and lower initial TP and that the difference in initial TP concentrations is shown as a difference in the concentration of insoluble protein fractions, which are eliminated during fermentation. By increasing the milling granulation in both kinds of wheat, there is a significant increase in the medium molecular protein fraction (MMW N), which is more pronounced in wheat with a lower starting concentration of TP, even though the starting concentrations of TSP in fine (O 0.2 mm) and the superfine milling (O \(<\) 0.2 mm) were similar. A significant drop in fermentability at the superfine granulation of the grain was noted. w _Applied_Mobile, 2024, 14, 9985.
caused by wheat are the additional burden of mash and word HMW N protein fraction and difficult filtration of mash due to the formation of residual protein gel and/or protein-pentosan gel [5; 6; 7] and a negative impact on colloidal stability, which indirectly affects the minimum shelf life due to the increased presence of so-called \"haze active\" proteins, mostly from gliadin fractions of wheat proteins [8; 9]. Groups of macromolecules that can cause process problems when using wheat are, in addition to proteins and araboxylans (pentosans), dextrins, which, according to some authors, have the greatest effect on the increase in viscosity, especially if they are prone to cyclization [10; 11; 12]. What, when used in brewing, is divided into four qualitative groups based on the TSP and mash viscosity values. The first group is the best; these are the varieties that give a low proportion of soluble proteins (0.65-0.78 g/100 g malt) with a good value for wort viscosity (<1.65 mPa\(\cdot\)s) [13], although it should be noted that different authors claim different values. The second group consists of varieties that give an increased proportion of soluble proteins with a satisfactory viscosity, the third group consists of varieties that have an increased viscosity and a satisfactory proportion of soluble proteins, and the fourth group consists of varieties that have unsatisfactory values for both indicators and are not suitable for the use in brewing. Weheat used in brewing usually has a TP between 10 and 13%. The protein complex of wheat is called gluten and is divided into four categories: glutenin, gliadin, albumin, and globulin. Gluten is a complex mixture of 50-100 individual proteins and is usually divided into two groups: polymorphic gliadins (\(\alpha\)-type gliadins, \(\gamma\)-gliadins, and \(\omega\)-gliadins with a molecular weight range of 30-80 kDa) soluble in 70% ethanol and polymeric glutenin (HMW N and LMW N fraction with the molecular weight range of 75-120 kDa and 30-74 kDa).