This paper describes the outline, goals, procedures, study sites, and analyses adopted in studying the relationships between grass, milk or cream and ripened Gruyère and Etivaz cheese. This was particularly aimed at testing whether mountain pastures (with a more diverse botanical composition) produced cheese with more flavour than lowland pastures. The study also focused on the characteristics of mountain cheese made using open wood fires to heat the milk. Four production sites were included in the study which took place from June-September 1995. The sites were selected to be as similar as possible in their production methods (with the exception of milk heating) but different in the botanical composition of the pastures. Two of the sites were located at between 1300 and 2100 m above sea level, 1 at approximately 1000 m and 1 at approximately 600 m. At each site, the following observations were made, repeated approximately 12 times: (a) the botanical composition of the pasture, (b) the chemical composition of the grass, (c) the chemical composition of the milk and cream, (d) the chemical composition of the ripened cheese, and (e) the sensory properties of the ripened cheese. Preliminary results, particularly with regard to the incidence of volatile terpenoids in grass from mountain areas and in milk, cream and cheeses are summarized. Further data will be published as available