Late Nitrogen Supplementation Partially Recovers Failed Fermentation During Mead Production

Abstract

For mead production, honey wort must be supplied with nitrogen to avoid slow or stuck fermentations or the production of undesirable flavor compounds. However, supplementation needs vary depending on wort composition and yeast strain, and studies involving the supplementation of honey wort are rare, and there are no studies on recovery from fermentative failures through late supplementation. Thus, honey wort at 25.5°Brix was supplemented with di-ammonium phosphate (DAP) or ammonium sulfate (AS) either 1) exclusively in the wort at 0.7 g/L; 2) after 14 days (0.3 g/L); or 3) in the wort and after 14 days, at 0.7 and 0.3 g/L, respectively, and fermentation was carried out during 26 d by the yeast Saccharomyces cerevisiae JP14. Non-supplemented wort resulted in failed fermentation, and late nitrogen addition partially recovered the process. Nitrogen addition at both stages improved yeast performance, which allowed the production of meads with higher concentrations of ethanol. Volatiles' production was also improved when nitrogen was added, especially when AS was the source. Wort early supplementation generated meads with higher concentrations of isobutyl alcohol, acetaldehyde, ethyl acetate and 1-propanol, and lower 2-phenyl ethanol; the latter was not affected by late supplementation. It was evident that the timing for nitrogen addition, besides the nitrogen source, significantly affected ethanol and volatile synthesis during mead production. Therefore, nitrogen sources and the strategy used for their addition can be used to control the chemical profile and sensory quality of meads.