This study describes a screening system for future brewing yeasts focusing on non-Saccharomyces yeasts. The aim was to find new yeast strains that can ferment beer wort into a respectable beer. Ten Torulaspora delbrueckii strains were put through the screening system, which included sugar utilization tests, hop resistance tests, ethanol resistance tests, polymerase chain reaction fingerprinting, propagation tests, amino acid catabolism and anabolism, phenolic off-flavour tests and trial fermentations. Trial fermentations were analysed for extract reduction, pH drop, yeast concentration in bulk fluid and fermentation by-products. All investigated strains were able to partly ferment wort sugars and showed high tolerance to hop compounds and ethanol. One of the investigated yeast strains fermented all the wort sugars and produced a respectable fruity flavour and a beer of average ethanol content with a high volatile flavour compound concentration. Two other strains could possibly be used for pre-fermentation as a bio-flavouring agent for beers that have been post-fermented by Saccharomyces strains as a consequence of their low sugar utilization but good flavour-forming properties.
- Klíčová slova
- Torulaspora delbrueckii, beer, non-Saccharomyces, screening, yeast,
- MeSH
- aminokyseliny analýza MeSH
- biologické modely MeSH
- chuť MeSH
- DNA fingerprinting MeSH
- DNA fungální chemie izolace a purifikace MeSH
- fermentace MeSH
- koncentrace vodíkových iontů MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- metabolismus sacharidů MeSH
- odoranty MeSH
- pivo analýza mikrobiologie normy MeSH
- technika náhodné amplifikace polymorfní DNA MeSH
- teplota MeSH
- Torulaspora chemie cytologie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny MeSH
- DNA fungální MeSH
