Yeast Energizer - 1 Pound Jar - Packaged in a plastic jar with a tamper evident air tight seal to ensure quality and freshness! Yeast energizer is a blend of diammonium phosphate, yeast hulls, magnesium sulphate, and vitamin B complex. Add 1/2 teaspoon per gallon of wine must to stimulate or restart a fermentation. Use 1/4 teaspoon per gallon in beer to revive a slow or stuck fermentation. Yeast energizer also works well in meads and honey brews to help create a complete fermentation.