Anaerobic digestion for the treatment of solid wastes is mostly performed by dry digestion technologies (Total Solid > 20%). Because of the low water content, incoming and fermenting wastes are pasty matrixes, and pumping of fresh waste as well as a good mixing efficiency are a challenge at the industrial scale. Despite the economical importance of dry digestion, the rheology of digested solid wastes is poorly characterized in the literature. One reason for this information deficit is the lack of a suitable apparatus to measure the heterogeneous media of digestates composed of coarse particles. For these types of wastes, it is impossible to use conventional moving-piece rheometers. We developed a practical and rapid rheometrical test for the analysis of real anaerobic digested solid wastes containing coarse particles. A “slump test”, mainly used in concrete industries, was built specifically to this purpose: yield stress can be estimated from the final slump height. Regarding the behavior of the slump, we conclude that digestates behave as viscoelastic materials. The yield stress of different digested Organic Fraction of Municipal Solid Waste (OFMSW) was measured and ranged between 200 and 800 Pa. An exponential law can be used to correlated yield stress and Total Solids content.