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Abstract. A continuous flow distillation unit was designed and operated to determine if energy use per unit of mint oil extracted could be reduced. This process showed that 95 to 100 percent of the oil could be extracted from the mint hay. The prototype distillation unit can process about a 1 metric ton of mint hay per hour depending on the settings. This process has the advantages of good steam contact with the hay, and the ability to control processing parameters such as feed rate and retention time. Mint hay was processed at moisture contents between 40 to 65 percent, which implies that hay can be processed within a few hours of being cut, thereby reducing weather-related risks to farmers. The major issue with this process is that plant particulate matter, entrained in the steam/oil vapor is getting into the separation tank and acting as an emulsifier that causes the oil and water to form an emulsion such that the oil will not separate from the water. Because of this oil separation issue, energy efficiency could only be roughly approximated. It was estimated that the process is at least 14 percent more efficient than conventional batch methods. Unfortunately, research in 2019 was limited due to a steam meter failure and a shortened harvest season so the energy efficiency couldn‘t be investigated further. The oil composition of the recovered oil was generally within the MIRC standard except for the Menthol content which was low.