This powerful skincare trio helps address dullness, uneven texture, and fine lines. This powerful skincare trio helps address dullness, uneven texture, and fine lines. After SK-II scientists observed the soft and youthful hands of aged sake brewers, they spent over five years isolating the single yeast strain that held the secret to soft, clear skin. With that, they developed their signature ingredient "Pitera" - a clear liquid rich in vitamins, amino acids, minerals, and organic acids derived from a controlled natural fermentation process.