Abstract: North American peppermint oils are widely regarded as some of the most superior peppermint oils commercially available. Amongst them is Yakima double-cut peppermint oil (Mentha piperita L.). It has an aroma described as strong, refreshing, minty, slightly creamy, and very herbaceous with some of the most desirable flavor notes among peppermint oils. The peppermint is grown in the Yakima Valley of Washington State, USA. As one of the most northerly grown peppermints with longer days, it is unique as there are 2 harvests of the mint leaves in one season. For this study, samples of fresh and dried (hay) leaves were collected from both harvests; 1st cut, July and 2nd cut, September. Steam-distilled oils were produced from each harvest and analyzed by gas chromatography-mass spectrometry to give detailed profiles. The aroma and taste sensory attributes of each oil were evaluated. In addition, menthyl formate has previously been reported only once in the literature, but not as definitively as required by current flavor-regulatory bodies for use as a natural flavoring ingredient. It was conclusively reported in these peppermint oils.