Investigation of hygiene conditions and development of quality assurance plan for beer production

Abstract

This degree project focused on the evaluation of the facilities, production process and conditions within a brewery production site in order to identify potential contamination risks in the beer production process and suggested actions for improving and enhancing protection against contamination. The project was performed in collaboration with a microbrewing company that produces beers with different yeast strains and bacteria. As they were planning to produce new beer products fermented with regular brewer’s yeast strains of Saccharomyces pastorianus ensuring that no cross-contamination would occur during production was identified as crucial.
In order to achieve this, literature research was performed which in combination with discussion with the brewers at the brewery provided an insight into the production process and the potential hazards. A variety of bacteria and wild yeast was found to pose a threat to the beer production process.
The air microbial load was investigated to evaluate the chance of airborne contamination. The efficiency of cleaning and sanitising for a fermentation tank and the canning machine was tested. The hygiene conditions of the canning equipment surfaces were also evaluated. Microbial testing of canned beer and beer from the tank was additionally performed as an indirect method to investigate potential contamination during the canning process.
The results showed increase in microbial load during the milling and canning process. Furthermore, presence of lactic acid bacteria that can pose a microbial threat in the quality of the finished product were detected in all tested stages of production. The evaluation of the cleaning process for the fermentation tank did not show clear results on whether the implemented cleaning procedure should be considered efficient and further investigation is recommended. The evaluation of cleaning process for the canning machine presented positive results but further monitoring will provide better insight about its effectiveness. The evaluation of hygiene conditions for the surfaces of canning line showed moderately positive results with no microorganism detection on direct with beer contact surfaces but detection in two indirect contact surfaces. As a result, improved cleaning practices are suggested. No spoiler microorganisms were detected in beer samples from the tank at conditioning stage and after canning indicating that no contamination occurred during production.

Popular Abstract

You might look at your beer in the glass and be captivated by the playful bubbles and the foam, or enjoy the colour of the beer and its smell before your first sip, but do you ever wonder how it is made and how safe it is for consumption? Well, probably not, after all you might have heard that drinking beer used to be safer and more pleasant than drinking the poor quality water that was available in big cities in the past. The truth is that no foodborne illnesses are associated with the consumption of beer since no pathogens are able to grow in it.
The boiling step in beer brewing kills any microorganisms present while at the same time regular beer is not a favourable environment for microbial growth due to hops, the low pH, the presence of ethanol and carbon dioxide as well as the lack of oxygen and nutrients. Only a few microorganisms are able to overcome these obstacles and grow in beer, but do not worry, they cannot make you ill. These microorganisms can spoil the beer by affecting its taste, smell or appearance and they can be a real headache for brewers but definitely not you.
Over the years, technological advancements have helped minimise the occurrence of spoilage in beer and improve its quality. Automation in production and monitoring systems have played an important role in eliminating production issues that will negatively affect the finished product. Additionally, under the modern brewing conditions, the beer has minimum contact with air preventing quality deterioration from microorganisms that require oxygen to grow. This, in combination with rigorous cleaning and sanitising practices are the main defence of breweries against microbial contamination. This might seem like an easy task, but the truth is that it is easier said than done. Brewery is a nutrient-rich environment where microorganisms can thrive and eliminating these favourable conditions for microbial growth is a contact fight.
Ensuring no microbial contamination and high quality finished beer can be even more challenging for small-scale production. Microbreweries have limited resources while the production is not fully automated and several activities might be exposed to air and performed manually. The implementation of high hygiene conditions under these circumstances can be even more crucial in achieving quality in every batch.
This degree project was performed in collaboration with a microbrewery where different styles of beers are produced using different yeasts and bacteria for fermentation increasing the contamination risk. During the project, the production facilities and process were evaluated and in combination with monitoring of the hygiene conditions a quality assurance plan was developed for the production of new beer products. The air in the brewery as well as different surfaces and equipment in production area were tested for microbial growth. Based on the results, the cleaning and sanitising practices were highlighted as crucial for preventing microbial contamination and regular monitoring of hygiene was recommended. Additionally, the general layout of the facilities and the air circulation were identified as factors that could influence the microbial load at the brewery. No spoilage microorganisms were detected in the tested beer samples indicating that no contamination occurred during production.

• author: Dimitriou, Stasini
• supervisor: Jenny Schelin
• organization: Biotechnology; Applied Microbiology
• course: KMBM01 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Quality Assurance, Applied Microbiology, Food Production, Beer Production, Food Quality
• language: English
• id: 9125304
• date added to LUP: 2023-06-19 12:40:59
• date last changed: 2023-06-19 12:40:59