Continuing our exploration in the "Why are Specialty Yeast Special?" series, let's delve into how these yeasts can complete fermentation under challenging conditions while minimizing undesirable off-odors and flavors.

Yeast can naturally produce compounds like hydrogen sulfide (H2S), acetaldehyde, and sulfur dioxide (SO2) during fermentation, especially when stressed. Understandably, the metabolic pathways within yeast that lead to the production of these compounds have been a large focus of genetic research and selective breeding.

Some yeast traits are genetically complex and traditional selective breeding and screening methods are an ineffective tool to target these traits. For example, if we breed two strains of wine yeast, one that produces low levels of H2S and another that produces low levels of SO2, it is not guaranteed that the daughter yeast is both a low H2S and low SO2 producer. This is because a large group of genes controls and influences these traits.

Quantitative Trait Loci (QTL) is a technique that allows us to pinpoint the location of all genes involved in complex yeast traits. Now when we selectively breed yeast we can quickly screen daughter strains for the desired trait. Combining QTL mapping with selective breeding has allowed Lallemand Oenology to produce a line of no to very low H2S, SO2, and acetaldehyde-producing strains including ICV OPALE 2.0™, ICV OKAY™, SENSY™ and PERSY™. This is a non-GMO technique; all QTL process strains are naturally bred. 

SpecialtyWineYeast WinemakingInnovation ShareKnowledge