Scale-up and scale-down strategies are a key for successful implementation of bioprocesses in industry. This issue of Biotechnology Journal, edited by Peter Neubauer (TU Berlin, Germany), features articles on methods for improved scale-up and -down strategies, e.g. measuring CO2 gradients, drop breakage analysis and study of metabolic stress. One review article by Alvin Nienow presents strategies for improved beer production (http://dx.doi.org/10.1002/biot.201000414). Cover image: Outdoor fermentation vessels at a Spanish brewery. ©Olaf Hendel (Versuchs- und Lehranstalt für Brauerei in Berlin (VLB) e.V.).