Estudo microbiológico na produção de cerveja artesanal para melhoria da sua qualidade

Abstract

Beer is considered one of the oldest alcoholic beverages produced and consumed in the world. Currently, depending on production process, there are two styles of industry, craft beer and industrial beer, and over the last few years, industrial beer has been losing market share to craft beer. The craft beer production process at Fábrica de Cervejas Portuense contains the following steps: Malt Milling – Brassing – Filtration – Boiling – "Whirlpool" – Cooling – Fermentation – Maturation – Centrifugation – Filling. The absence of a sterilizing filtration and/or pasteurization step prior to filling makes this style more susceptible to microbiological contamination and wastage. In the hot phase of production (from the malt milling to the “Whirlpool”), where high temperatures are applied, control is considered to be ensured, but the same is not true in the cold phase (from cooling to filling). In the intership carried out, in addition to monitoring the brewing production, a microbiological study was performed on the equipment and materials used in the cold phase of the process, as well to the beer in tank and to the final beer, in order to evaluate the quality of the beer and determine points of contamination. For this purpose, it was analyzed the presence of Lactobacillus and Acetobacter, as quality indicator bacteria, and the presence of bacteria belonging to the Enterobacteriaceae family, as hygiene indicators. The results showed that, despite the existence of high-quality beers, some were contaminated and that the contamination could occur at various points in the process.

Date of Award	7 Jun 2023
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Paula Teixeira (Supervisor)