Zinc
An ion that is a yeast nutrient but that at high levels gives a metallic taste to beer.
Zymase
A group of enzymes (originally found in yeasts and bacteria) which, in the presence of oxygen, convert glucose and a few other carbohydrates into carbon dioxide and water or, in the absence of oxygen, into alcohol and carbon dioxide or into lactic acid.
Zymurgy
The science or study of brewing and fermentation.