Abstract: The present invention relates to a process for improving the organoleptic properties of wines comprising the step of treating standing grapes that will be used for wine production less than one month before harvest with a composition containing, as active ingredient, at least one anionic surface-active agent capable of rendering the cuticle of grapes hydrophilic, said composition being applied at a rate of about 5 to 50 liters per hectare.The standing grapes are preferably sprayed with an aqueous suspension containing less than 20% by volume of a composition containing, as active ingredient, an alkali metal, preferably potassium, salt of an unsaturated fatty acid containing at least 16 and preferably 18 carbon atoms of an alkali metal, preferably posassium, salt of sulphate-containing fatty alcohols containing a significant proportion of C.sub.16 to C.sub.18 fatty alcohols or a sulphonated oil, such as an alkali metal sulphooleate of sulphoricinoleate.