Abstract
Centrifugation and aeration were unsuitable pretreatments before anaerobic digestion of press liquors from citrus peel. Non‐aerated fermentation without pH control resulted in conversion of sugars to acids and ethyl alcohol with reduction in pH to 2.8 ‐ 3.5. These acidified liquors had a pleasant smell, were stable on storage and were satisfactory feedstock for anaerobic digestion.