The chemical composition of berries at harvest, which will affect wine styles, is determined by complex physiological processes occurring from set through the fruit’s lifetime to maturity, and this is closely intertwined with environmental and crop management factors. Among those factors, climatic conditions within the fruit zone (i.e. microclimate), such as light and temperature, are well-known to affect the physiology of the fruit at the skin, pulp and seed levels. This article will present the potential of leaf thinning in the bunch zone to modify cluster microclimate and berry composition.