Sensory scorecards for salt tasting

Abstract

Earth Sciences are perceived by students as abstract disciplines with little connection to everyday life, making it difficult to motivate learners and demonstrate their social relevance. This OMADO presents the scorecards to develop a context-based educational experience that uses table salt to integrate Geology, Chemistry and Food Science into an interdisciplinary learning sequence for Secondary Education. The proposal is organised combining sensory analysis, chemistry and geological interpretation. Students first become familiar with the methodology of formal sensory analysis by recognising the basic tastes and using tasting protocols. They then prepare and evaluate sodium chloride solutions of increasing concentration to determine salt taste thresholds while reinforcing concepts such as dissolution, concentration and experimental observation. The central activity consists of a blind tasting of commercial salts representing different geological origins and production methods (marine, mountain spring, rock, refined and fleur de sel salts). Students complete tasting sheets adapted from professional sensory analysis, assessing attributes such as saltiness, bitterness or astringency. The results are compared and discussed collectively, allowing students to identify similarities and differences between samples before relating their observations to geological origin, mineral composition, evaporitic environments, extraction methods and industrial processing. According to the educational level, the experience can be complemented with simple laboratory activities involving the preparation of saline solutions and concentration calculations, extending the proposal towards practical Chemistry without increasing its technical complexity. The learning sequence promotes observation, hypothesis generation, data recording, collaborative discussion and evidence-based interpretation, transforming subjective sensory perception into scientific analysis. Rather than approaching Geology, Chemistry and Food Science as independent subjects, students construct links between geological processes, chemical composition, food properties and human use of natural resources. The activity also provides opportunities to discuss sustainability, gastronomy, cultural heritage and responsible resource management, reinforcing the societal relevance of Earth Sciences through an everyday context.