For the sake of sustainability, more and more people are trying to avoid using standard ‘coffee-to-go’ cups in order to produce less waste. However, many bakeries and cafés still refuse to fill cups brought in by customers on the grounds of hygiene.
In his final dissertation for the Food Science degree programme, supervised by Prof. Dr Dirk Bockmühl, Professor of Hygiene and Microbiology at the Faculty of Life Sciences, he identified the hygiene risks faced by consumers when drinking coffee from fully automatic coffee machines. It became clear that the coffee machine can be a source of microorganisms and that, in particular, bacteria can subsequently be found in the brewed coffee itself. Although there is as yet no evidence of a health risk from contaminated coffee, it is advisable to clean fully automatic coffee machines regularly. According to the study’s findings, a high coffee temperature also helps to prevent high levels of bacterial contamination.
The findings of this master’s thesis support the use of reusable cups as an alternative to ‘coffee-to-go’ cups. It was demonstrated that the potential bacterial load from reusable coffee cups is negligible compared with the potential risks posed by a poorly maintained machine.
Philip Heldt, who oversaw the project on behalf of the NRW Consumer Advice Centre, welcomes these findings and sees them as confirmation that the use of reusable cups should continue to be promoted, not least for environmental reasons.
