Evaluating the German demand for organic food in the majority of cases has been done by interviews, which are restricted by massive overestimation of consumers themselves. By using consumer panels, it is possible to survey actual consumer behaviour in combination with consumer attitudes and socio-demographic data and also by additionally requested consumers’ stated buying behaviour. Such methodology enables exposure and quantification of the gap between stated and actual buying frequency. Also the dimension of conventional products bought by mistake, while intending to get organics, can be identified. These results may give considerations for prospective survey design and adjustment of marketing policy