Speaker: Philippe Janssens

Hoppy beers continue to be popular among beer lovers. Many compounds in hops have been shown to impart pleasant flavor to beers, and there is extensive literature about the impact they produce on final products. Recently, a minor group, denominated as polyfunctional thiols, caught the attention of brewers due to the pleasant fruity flavors they impart to beer. Because a substantial number of these thiols are found to be flavorless precursors in hops (e.g., cysteinylated and glutathionylated precursors), brewers are looking for practices to increase the rate of their release.

Yeasts are known to play an important role during fermentation in releasing the volatile thiols through enzymatic activity, however little practical information is available to brewers. Fermentis has worked to identify the best yeast strains (lager and ales) and fermentation conditions (temperature, wort density, maturation time) to allow maximum the citrus and passion fruit odors as a result of 3-sulfanylpentan-1-ol (3SPol), 3-sulfanyl-4-methylpentan-1-ol (3S4MPol), and 3-sulfanylhexan-1-ol (3SHol) presence in beer. The results we’ve found can help brewers maximize the thiol release from its precursors through yeast strain choice and optimization of fermentation conditions.