The questions I have are:

1) What is are the commercially available options available to the average homebrewer for adding zinc to yeast and of those, which are more available, affordable, and unlikely to affect flavor of the beer due to either the formulation or additives?

2) What is the best way and time to add zinc? In an aerated starter?During the boil? During yeast pitching? Other?

Regards,
Lou Heavner

RESPONSE:

Lou, Most of the commercially available nutrients contain some zinc mainly in mineral form as ZnSO4 or ZnCl2. Adding mineral zinc directly, which is probably the cheapest way of adding zinc, is difficult for home brewers because of the small amounts. Addition of 0.2-0.3 ppm zinc (0.4-0.6 mg/L ZnCl2 or 0.5-0.7 mg/L ZnSO4) is not easy to measure without a proper scale. We have developed a mineral enriched yeast called Servomyces, which adds about 0.25-0.3 ppm zinc to the wort if used in the recommended manner.

Studies with various universities and breweries have shown that zinc from Serotypes is better available to yeast than just mineral zinc. This product is available in capsules now, which contain the right amount for 20-22 L of wort. For most commercial nutrients it is recommended to add it to the kettle 10-15 minutes before the end of the boil. This way the nutrient is dissolved properly and you have a sterilization effect. Mineral zinc can be added together with the yeast.

Regards,
Forbes & Tobias