Not only is S. cerevisiae the main character in the beerbrewing but yeast also has the centre stage role in other biotechnological industries benefiting mankind (alcoholic beverage production, bread baking, fine chemicals and
bioethanol). The earlier predictions that yeast fermentation for the production of bioethanol as a replenishabe energy
source is being realized because industry is now embracing this technology. The main difference between bioethanol
fermentation and beer fermentation is the final product requirements. Bioethanol fermentations require ethanol as
the main product at the highest yield for the process. In contrast, beer fermentation aims for well-balanced flavourful
products containing ethanol. The script of the process is based on years of investigations to understand the requirements
of yeast and how best to treat the yeast for enhanced performance and balanced flavour production. The various
aspects discussed under cellars (hygiene requirements, propagation, fermentation and yeast handling) showed that the
multifaceted process has various interlinked factors that need to be considered in the design of economic and effective brewing processes. The reward for careful planning and optimization, based on the requirement of the main
character S. cerevisiae, ultimately results in an enjoyable and refreshing beverage.