OnTap Magazine

Repetition After candidates are selected, the process can be repeated to hopefully obtain better hybrids: a second-generation hybrid if you are so inclined. Typically, the process is halted until candidates are found that meet the criteria. Until the proper candidate(s) are found that pass all the tests they need to. THE BREEDERS Academic institutions with prominent biotechnology and microbiology departments have been breeding yeasts for academic as well as industrial purposes for decades. Stellenbosch University and the Agricultural Research Council have bred wine hybrids for the industry to tackle problems in fermentation such as nitrogen demand, sulphur production and volatile acidity production. They have also looked at other factors such as improving wine aroma and flavour. Similarly in beer, work performed at biotech companies associated with the University of BritishColumbia inCanada has bred new beer hybrids of S. cerevisiae . One example is a new strain that produces low H 2 S concentrations during fermentation. An extra benefit of this hybrid is that is allows the brewer to produce a Saison-styled beer without the risk of cross-contamination. The STA gene found in standard saison yeasts is what gives the beer its characteristic dryness, but this gene is not present in the new strain, eliminating any possibility of that beloved lager in the next tank taking on the dryness and mouthfeel of a saison and accidentally ending up as a brut lager. If you would like to achieve the typical dryness in a saison, then adjusting your mash regime for higher fermentability and attenuation or using an enzyme to mop up those dextrins will result in an excellent saison beer. Otherwise, this new hybrid is a great solution to produce any Belgian oriented beer with low chances of H 2 S in standard conditions. Indeed, yeast breeding is a way to address problems or fulfil demands in the industry. Certain yeast strains have been selected by the likes of brewers over centuries for fermentation performance and consistency over many re-pitches. This has resulted in many brewer’s yeasts losing the ability to sporulate and only reproduce via budding since this was the trait selected for, making recombination very difficult. Therefore, very few brewing strains can be bred and have their hybrids subsequently commercialised. Conversely, wine-making strains are a lot easier to breed because of their biodiversity in the vineyard and the seasonal nature of the industry. Strains that are not selected for “re-pitching” and have a greater chance to be compatible for breeding. WHAT THE FUTURE HOLDS In recent years we have seen an increased interest in producing hybridised brewing strains, despite the inherent difficulty of hybridising brewing yeasts. Targeting yeast- derived beer faults will certainly be the focus, such as H 2 S, diacetyl, acetaldehyde, attenuation, and flocculation to name a few. Other parameters such as fermentation speed, flavours/aroma or temperature tolerances will certainly be considered too. Nevertheless, all these endeavours should certainly increase the available options of yeast to a brewer, rather than narrowing it down to “the perfect yeast”. There are simply too many options for beer styles and subdivisions of the styles to create one yeast to tick all the boxes. We should expect to see a range of new hybrids to stand alongside the tried and tested isolates we have come to know in brewing. It is important to note yeast breeding is completely void of GMO methods. No foreign DNA is inserted into cells nor are any genes directly knocked out of the genome. Selective breeding is a method that has been in our employ since mankind began animal husbandry and crop farming. GMO FREE Farmhouse™      TEMPERATURE RANGE AROMA & FLAVOR ALCOHOL TOLERANCE ATTENUATION RANGE