Osmotolerant yeast is a special strain of instant dry yeast that performs better in high-sugar doughs than other yeasts do. In small amounts, sugar enhances fermentation, but when the amount of sugar exceeds about 5% of the flour weight, it impedes fermentation by pulling water away from the yeast. (If you’re a science geek, you probably know that sugar creates osmotic pressure, and if you’re not, you probably don’t care.) - See more at: http://www.wildyeastblog.com/osmotolerant-yeast/#sthash.7y0ItMKi.dpuf