AYF 1000™ is a yeast nutrient for use in fuel ethanol fermentations. It contains a proprietary blend of enzymes, inorganic nitrogen, organic nitrogen, and trace minerals to provide yeast with the correct nutrient balance for growth and reproduction. AYF 1000 increases yeast budding and maintains yeast in their rapid growth phase through more of the fermentation. Higher concentrations of more actively growing yeast produce alcohol faster, consume sugars more efficiently, and leave less residual sugar at the end of fermentation. AYF 1000 has no adverse effects of byproducts and may improve their production and composition by reducing residual sugars.