Diagram of recommended apparatus for assaying total oil in hops from ASBC MOA Hops-13,
Flask is 5L. Oil winds up in the vertical tube on left side of "distilling receiver" floating on top of water. This tube is calibrated in tenths of a mL. Hops and water are placed in flask and boiled. Vapor,mostly water but containing essential oils, rises through vertical tube from flask, passes along nearly horizontal tube in receiver and enters the condenser (300 mm Alihn) where the vapor and oil condense falling back into vertical tube in receiver. This fills up with water (with oil floating on top) until full enough that there is overflow back into the vertical tube from flask through V shaped siphon tube. Thus water continues to recirculate until all hop oil is extracted (4 hrs after commencement of boil).