Preferences for food products are usually analysed employing multi-attributive Attitude Measurement, Conjoint Analysis and recently Discrete Choice Modelling approaches. From a theoretical point of view, Choice Modelling based on random utility theory (RUT) outperforms traditional Conjoint Analysis because of its microeconomic foundation. In this article, consumers' choice behaviour on ecologically produced sausages is analysed. A market experiment reveals brand specific reactions towards the 'Bio-Siegel', a German quality label for organic food introduced in 2002. It can also be shown that regular customers of organic food are much less price sensitive than occasional buyers.