DARK AND LIGHT HONEYS: WHICH IS BETTER FOR MEAD FERMENTATION?

Mead is a beverage with alcohol content between 8 and 18% v/v, produced from the fermentation of a diluted honey solution. The fermentative process of this beverage is strongly influenced by the yeast strain and the type of honey used. The present work aimed to test two samples of honey (a light one and a dark one) in the fermentative process of mead by three yeasts (S. cerevisiae Montrachet, S. bayanus Premier Blanc and S. cerevisiae Safbrew T-58), incubated at 30 °C and 150 rpm for 24 h. The fermentations were carried out in 500 mL Erlenmeyer flasks containing honey must (30 oBrix), supplemented with yeast extract (5 g/L), malt extract (5 g/L), peptone (10 g/L), magnesium chloride (0.05 g/L), ammonium sulfate (0.3 g/L) and ammonium phosphate (0.05 g/L), inoculated with an initial culture of 106 cells/mL and incubated at 30 °C for 264 h. The fermentation monitoring was performed every 24 h from the collection of samples The concentration (cells/mL) was determined from counting performed in Neubauer chamber, the ethanol content (% v/v) was determined through the bench-type densimeter and the reducing sugars were quantified by the spectrophotometric method - DNS (3 - 5-dinitrosalicylic acid) with wavelength of 540 nm. A higher cell growth was observed: S. cerevisiae Montrachet (9.5 x 107 cells/mL, 72 h), S. bayanus Premier Blanc (9.2 x 107 cells/mL, 72 h) and S. cerevisiae Safbrew T (6.1 x 107 cells/mL, 96 h), as well as a higher substrate consumption (80.7%, 86.3% and 73.8%) and higher ethanol production (14.0%, 15.0% % and 12.7%), respectively, in the fermentation of the must produced with dark honey, which provides higher concentration of essential nutrients (proteins and mineral) for to a better cell growth and metabolic activity of the yeasts.