Servomyces is a natural zinc enriched single-strain brewing yeast (from the prestigious Hefebank Weihenstephan) that is used as a biological yeast nutrient.  Servomyces enables any yeast strain's ability to incorporate essential nutrients into its cellular structure while providing a high concentration of zinc that is essential for healthy alcoholic fermentation.  Tested in breweries around the world, it has been proven to:

For commercial brewers, Servomyces is available in 20 packs of 10 grams or 500 gram packages. For homebrewers, Servomyces is available in blister packs of six capsules, each of which can be used for a 5-gallon batch (20 to 25L). Servomyces is beneficial to beer, wine, mead and cider.

Homebrew notes: Add by breaking open 1 capsule and pouring the supplement in 10 minutes prior to the end of the boil. OR, if your fermentation does not require a boil, open the capsule and pour in the supplement before you pitch the yeast.