Fed-Batch and Staggered Nutrient Addition: An Improved Method for Mead Production

Abstract

Mead is an alcoholic beverage made from fermented honey wort. Honey is manly composed of glucose, fructose and water, but it lacks nutrients, including nitrogen, which reduces ethanol yield and influences the production of aroma compounds by the yeast. This work describes the influence of fed-batch and staggered nutrient addition processes in substrate consumption, ethanol formation, yeast growth and production of glycerol, acetic acid and volatile alcohols during mead production. A positive relationship was found between wort's nutrient content and yeast growth. Fed-batch and staggered nutrient addition led to a mead with higher ethanol and lower residual sugar concentrations, with a positive relationship between nutrient addition and glycerol formation. Fed-batch and staggered nutrient addition showed to be an improved method for mead production, resulting in 90% efficiency for ethanol production by the yeast and intermediate concentrations of isoamyl alcohol (441.9 mg/L), isobutyl alcohol (7.6 mg/L) and phenethyl alcohol (1.4 mg/L) during the fermentation of a 150 g/L supplemented honey wort. Staggered nutrient addition, associated or not with fed-batch, showed to be an improved alternative method for mead production.