Speidel has developed a stainless steel fermenting egg that combines the advantages of the egg shape with the advantages of a stainless steel tank and a unique design. The Black Eye looks like a space satellite from the outside and provides a gentle and well controllable fermentation inside. Due to its unique shape, the yeast can circulate smoothly during the fermentation phase. In science it is assumed that this free circulation is an advantage for the fermentation process and thus for the entire aroma spectrum. Thanks to the perfect welding seams and the highly smooth inner walls, the fermenting chamber is also very easy to clean.