Study of scale variation in reactors used in the saccharification step for the production of Pilsen craft beer.

Beer is the most consumed beverage in Brazil and currently the segment of craft beers is growing responsible for the implementation of factories in the country. Often the size of the production line does not meet all stages of production, making it necessary to create production plants with different sizes, consequently, a study of variation of scale. The State University of Santa Cruz has a brewery with pilot scale plant, with saccharification reactor with a volume of 250L (with 56 rpm of agitation) that is incompatible with one of the proposals of this plant, which is the scientific research. A cylindrical stainless steel reactor with a volume of 5L, with 0.185m of diameter and height, was proposed with a paddle type agitator (diameter 0.06m). The scale-down study was performed according to the analysis of the maintenance of the conversion parameters: "Reynolds number", "mixing time", "agitator pumping capacity", "non-aerated system power per volume" and "speed at the end of the impeller, with agitator set at 20000, 56, 112, 640 and 1530 rpm, respectively. Saccharification was performed (4L of water and 1.34kg of malt) for each of the scale conversion parameters and the evolution of the reaction was measured by kinetic test, where periodically a 0.005L aliquot was removed for refractometer reading, and determination of soluble solids. The results showed that among the conversion factors analyzed, the one that maintained the reaction on a small scale, similar to a large scale, was the parameter "non-aerated system power by volume". It was possible to obtain a miniature reactor with 5L operation capacity and 640rpm agitation compatible with use for research and development of new formulations, the results of which are compatible for pilot scale production of the brewery in question.