AimsWe compare the evolution of the microbiota of grapes grown following conventional or biodynamic protocols during the final stage of ripening and wine fermentation in a year characterized by adverse climatic conditions. Methods and ResultsThe observations were made in a vineyard subdivided into two parts, cultivated using a biodynamic and traditional approach in a year which saw a combination of adverse events in terms of weather, creating the conditions for extensive proliferation of vine pests. The biodynamic approach was severely tested, as agrochemicals were not used and vine pests were counteracted with moderate use of copper, sulphur and plant extracts and with intensive use of agronomical practices aimed at improving the health of the vines. Agronomic, microbiological and chemical testing showed that the response of the vineyard cultivated using a biodynamic approach was comparable or better to that of vines cultivated using the conventional method. ConclusionsThe work suggests that biodynamic cultivation of the grapevine may be sustainable even in difficult conditions, representing an interesting alternative to traditional vine-growing approaches. Significance and Impact of the StudyThis theme is topical and of interest to winemakers and consumers today, but is not easy to study due to the difficulties in finding vineyards with homogeneous characteristics, cultivated using different agronomical protocols. The particular climatic conditions observed in 2014 made this year a rare model, making it possible to verify the applicability of biodynamics to vine growing. The strict experimental plan gave results particularly useful for understanding the features of grape microbiota in a biodynamic context.