Researchers in Spain studied the effects of nine different treatments of a craft beer in a pilot plant, studying fermentation and dry-hopping types. Quality parameters of the beer such as polyphenols, antioxidants, bitterness, colour and alcohol were analysed.
Results showed that dry hopping in maturation with warm temperature increased the bitterness from 33 to 40 IBUs. The treatment using two yeasts and two fermentation temperatures resulted in the highest antioxidant capacity of the beer (around 92%). Antioxidant activity was increased by late dry hopping using ale yeasts for fermenting..
The authors state that the combined use of ale and lager yeasts seems to increase the antioxidant capacity and total polyphenol content of beer. Antioxidant activity is increased by late dry hopping.
Source: Gerhards, S., Talaverano, M.I., Andrés, A.I., Sánchez-Vicente, C., Lozano, J., García-Latorre, C., Petrón, M.J. and Rodrigo, S. (2021), Different dry hopping and fermentation methods: influence on beer nutritional quality. J Sci Food Agric, 101: 2828-2835.