Finnish solution prevents beer bottle explosions

An increasing problem in the brewing industry are contaminant yeasts that may result in beer bottle explosions, off-flavours, increased alcohol and over-carbonation.

VTT

’s solution detects these problematic diastatic yeasts, which stem from the same species as regular brewing yeasts and are consequently difficult to differentiate. The diastatic yeasts carry an extra gene, STA1, which may produce an enzyme that causes the reaction.

It’s an industry standard to test for the presence of STA1. However, because not all strains that carry the gene are problematic, the tests may lead to brewers disposing of beer batches that could have been sold.

“At VTT we have discovered why some strains with the gene are active, and therefore problematic, while others are not,” said Kristoffer Krogerus from VTT. “The difference was due to a deletion in the promoter of the STA1 gene – in other words, the genetic sequence in front of the gene controlling how much the gene is expressed.”

VTT’s test can be used in exactly the same fashion as the current industry standard, but it allows brewers to detect strains with the active STA1 gene.