8.15am breakfast briefing (finishes at 9am)
Yeast nutrition to enhance beer aroma-active compounds
Abstract
Aroma- and flavour-active thiols, long known for their sensory impact in wine, have been identified only recently in beer. These highly volatile aroma-active compounds are becoming more relevant, especially in craft brewing, as consumer demand for tropical aromas in hop-forward beer styles, such
as West Coast and New England IPAs and modern lagers, continues to rise.
Originally identified in wine, three potent thiols are known to give tropical fruit-like aromas to beer.
They exist in free and bound form in hops, often variety-linked; and to a lesser extent in malted cereals such as barley and wheat. Their release is linked to the yeast gene IRC7, which encodes the carbon sulphur enzyme β-lyase, responsible for cleaving cysteine- and glutathione-conjugated thiol
precursors and their biotransformation into aroma-active forms wines made from Sauvignon grapes are rich in aroma-active thiols, yet the grape itself has predominantly the bound forms; prompting brewers to add Sauvignon grape skins to the mash rather than late hop. In contrast to wine yeast,
most brewing strains lack a functional IRC7 gene, leading to the development of ‘thiolized’ yeasts using gene editing.
Yeast strains have also been altered with GM techniques to promote thiol expression in beer. Building on our research on aroma-active compounds during wine production, this study focuses on enhancing aroma and flavour sustainably through complex interactions of yeast nutrition, amino acid
composition and pH in wort fermentations. The aim being to remove the need for increased hopping, use of grape-skin based aroma boosting products, and avoiding GM yeast.
Register here: https://www.eventbrite.com/e/aeb-webinar-tickets-954939258027?aff=oddtdtcreator
