Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts

摘要

In this work, fermentable sugar, total protein, phenolics and ferulic acid content were estimated in sweet worts at different points of lautering. Transfer of these selected malt compounds into worts was analyzed in relation to the method of malt milling (wet milling of malt - the "test worts" or dry milling of malt -the "reference worts"). Glucose, maltose and maltotriose were more rapidly transferred into sweet worts at the early stages of lautering (40 hL and/or 80 hL of wort) after wet milling in comparison to dry milling. Total protein content in the test worts was significantly higher than in the corresponding reference worts at each stage of lautering. Transfer of phenolic compounds and ferulic acid (in the free as well as in the ester form) from the mash into sweet worts was significantly improved by dry milling, but not by wet milling. No difference in the total antioxidant activity was observed between the two types of worts. In conclusion, it can be stated that wet conditioning of malt before milling enhances the fast transfer of fermentable sugars and proteins from the mash into the sweet wort during lautering. Lautering is a time-consuming process, and time reduction without the loss of wort quality should be a priority. Therefore, wet milling can be of interest to professionals in the field as an interesting alternative method to improve the mashing process.