Brewing Efficacy of Non-Conventional Saccharomyces Non-cerevisiae Yeasts

James Bruner,Andrew Marcus,Glen Fox

doi:10.3390/beverages7030068

Abstract

Consumer demands for new sensory experiences have driven the research of unconventional yeasts in beer. While much research exists on the use of various common Saccharomyces cerevisiae strains as well as non-Saccharomyces yeasts, there exists a gap in knowledge regarding other non-cerevisiae Saccharomyces species in the fermentation of beer, in addition to S. pastorianus. Here, five distinct species of Saccharomyces from the UC Davis Phaff Yeast Culture Collection, as well as one interspecies hybrid from Fermentis, were chosen to ferment 40 L pilot-scale beers. S. kudriavzevii, S. mikatae, S. paradoxus, S. bayanus, and S. uvarum yeasts were used to ferment wort in duplicate pairs, with one fermenter in each pair receiving 10 g/L dry-hop during fermentation. Analytical measurements were made each day of fermentation and compared to controls of SafAle™ US-05 and SafLager™ W 34/70 for commercial brewing parameters of interest. Finished beers were also analyzed for aroma, taste, and mouthfeel to determine the flavor of each yeast as it pertains to brewing potential. All beers exhibited spicy characteristics, likely from the presence of phenols; dry-hopping increased fruit notes while also increasing perceived bitterness and astringency. All of the species in this study displayed great brewing potential, and might be an ideal addition to beer depending on a brewery’s desire to experiment with flavor and willingness to bring a new yeast into their production environment.

Highlights

Changing demands by beer drinkers in search of new sensory experiences are driving research into novel fermentations [1,2,3,4]
With a mean original gravity (O.G.) of 10.2◦ Plato (±0.36) due to a higher brewhouse efficiency than expected for the recipe designed at 10.0◦P (Figure S2)
Fermentations were carried out at 20.0 ◦C, standard ale temperatures, and analytical parameters were measured on each day of fermentation

Summary

Introduction

Changing demands by beer drinkers in search of new sensory experiences are driving research into novel fermentations [1,2,3,4]. Much of this research has utilized non-Saccharomyces yeast strains [5,6,7,8,9,10,11,12], which can be attributed to the rise in popularity of mixed-fermentation beers [13,14,15] This pursuit of distinctive aromas and flavors has driven the increased use of non-cerevisiae Saccharomyces species in the alcoholic fermentation of all beverages [16,17,18,19,20,21,22]. In addition to novel yeast-derived flavors, brewers are increasingly turning to dryhopping to enhance their consumers’ sensory experience This procedure of adding hops (Humulus lupulus) cones to beer when fermentation is active or finished was performed to provide microbial stability in packaging and during transport [27,28]. More recently, with the rise of craft and micro brewers, dry-hopping with pellets or advanced hop products [29] has become a common tactic used by brewers desiring to add interesting flavors and aromas to their beer [30]

Objectives

Methods

Results