Muscat This fruit was left on skins for a total of ten days. It was destemmed into the fermenter bin with zero sulfur added and then let the native yeast build up a population, which took about five days. From there the must was allowed it to go another five days fermenting on skins. Keeping the phenolic nature of Muscat Blanc grape skins in mind, the team was cautious about how long to leave on skins and they very happy with the result!