WE.2.E || Mobilizing LCA Resources Through Digital Collaboration

Ristic, Dusan; Jäger, Henry; Smetana, Sergiy; Heinz, Volker

Online experiment “The Ultimate Cheeseburger” took place in spring 2021. The experiment aimed to measure the average time necessary to cook different kinds of burgers in the same way, which is understood to reflect the amount of energy invested in preparation of burgers. The participants were cooking the burgers simultaneously, in different kitchens at different locations. Participants defined the moment to end the cooking themselves, considering personal perception and preferences. Additionally, participants used different cooking equipment (different stoves, pans, cutlery), all of which may have influenced the result of the experiment. To assess the reliability and repeatability of the obtained results, it was decided to prepare 20 burgers as explained during the online experiment “The Ultimate Cheeseburger” and follow the preparation time. The burgers were cooked by the same person with no formal cooking education or experience (the first author) who was also the sole responsible to decide when the burgers were cooked. The cooking was conducted in 4 repetitions (5 burgers per repetition). Each repetition was prepared on different stove and by use of different equipment. The obtained results and conclusions demonstrate that human factor (including combination of equipment properties and subjective decision) influences the amount of energy invested in the cooking phase. Cooking of beef burgers resulted in wider ranges of results generated in the scope of ± 35%, while for frying less familiar foods, people appear to have followed the instructions on the packaging and chef’s recommendations more precisely: ± 20%. The results of the subsequent reliability and repeatability assessment were fully within the scope of the results obtained during the experiment. Even though these results are not absolutely consistent, they are significantly (p ≤ 0,1) more consistent than the results of the experiment, proving the decisive influence of human factor on experiment results.