Abstract
Hop polyphenols influence beer flavour stability, antioxidant capacity, bitterness perception, colour development, and colloidal behavior, but their retention changes during wort boiling and maturation. This study investigates hop polyphenol retention across thermal processing and post-fermentation storage. Brewing trials were conducted using different hop addition timings and boiling durations while maintaining constant wort composition and fermentation conditions. Total polyphenols, flavanol concentration, bitterness units, turbidity, colour intensity, dissolved oxygen, haze formation, and sensory stability were evaluated during wort production and maturation. The results show that longer boiling reduced measurable polyphenol retention due to thermal degradation and precipitation with wort proteins. Late hop addition improved polyphenol preservation but increased the need for colloidal stability control during maturation. Moderate polyphenol retention enhanced oxidative stability without producing excessive haze. The study demonstrates that hop timing and maturation conditions must be optimized together to preserve beneficial polyphenols while maintaining visual clarity and balanced beer quality.