This protocol describes a cost effective method for generating highly concentrated yeast whole cell extracts (WCE) at concentrations of 50 μg protein/μl or 0.3 A260nm/µl. Highly concentrated extracts are used for many applications such as protein purification, purification of protein complexes (in particular when interactions are weak), protein-protein interaction studies, and velocity sedimentation studies. Normally highly concentrated extracts are generated with homogenizers or the French press. However, such equipment 1) is expensive, 2) is not available to every researcher, and/or 3) often cannot be used for cells from small culture volumes. The procedure described here can be used for breaking cells originating from cultures as small as 100 ml, although a culture volume of at least 200 ml gives the best result. Furthermore, this method is also effective for breaking formaldehyde crosslinked cells.