The present invention relates to a method for obtaining rubber from rubber-containing plant material, the method comprising the steps of subjecting a composition comprising rubber-containing plant material and a fermentation culture to conditions allowing anaerobic fermentation, wherein the composition preferably has a water content of less than 95 wt. %. The fermentation preferably does not involve movement of the rubber-containing plant material (or parts thereof), and preferably the fermentation is performed in the absence of oxygen ventilation. Additionally, it is preferred that the fermentation culture is cycled through the composition by percolation. A further step of the method involves obtaining the rubber from the composition.