Beer processing in large, outdoor tanks is no longer a novelty. Experience has been accumulated with fermentation and storage in various countries and under a variety of climatic and other conditions. Advantages are possible with regard to capital investment, construction time, operating cost, and product quality. It is no longer possible to use traditional approaches in the design of such facilities. Thorough engineering studies of all mechanical, chemical, and biological aspects are a prime prerequisite to a successful installation. Materials of construction, vessel design, types of insulation, cooling systems, fluid regime in fermentation, yeast management, agitation, heat transfer, automatic cleaning---all require careful consideration for the development of optimum design criteria.