Abstract
Barley malt modification controls starch accessibility, enzyme activity, protein breakdown, cell-wall degradation, and fermentable sugar release during mashing. This study investigates how different malt modification levels influence fermentable sugar production in brewing. Malt samples with low, moderate, and high modification were mashed under controlled temperature and liquor-to-grist conditions. Extract yield, maltose release, glucose concentration, maltotriose formation, dextrin distribution, wort viscosity, free amino nitrogen, and lautering behavior were evaluated. The results show that highly modified malt produced faster sugar release and lower wort viscosity, improving extract recovery and filtration performance. Moderately modified malt provided a balanced profile by supporting fermentability while preserving body-forming components. Low-modification malt showed restricted starch accessibility and slower enzymatic conversion. However, excessive modification reduced some structural compounds important for mouthfeel and foam quality. The study demonstrates that malt modification must be matched with beer style and process objective to achieve stable fermentability and wort quality.