Grimstad Brewery Withdraws Christmas Beer Due to Unwanted Yeast Contamination: What You Need to Know

It has not been found before
The reason for the withdrawal is that the yeast form diastaticus was in the batch, according to Agderposten.

“Of course we think it’s a shame, but ‘Merry Christmas‘ will definitely return in 2025″, said general manager Sverre Orm Øverland at the newspaper’s brewery.

The Grimstad brewery usually launches 15 different types of Christmas beer, but this year they chose to withdraw one of them after a quality check.

Some dark Christmas beers are already brewed in January. At that time, the beer was tested in the laboratory and went through chemical and microbiological analyses. According to Øverland, this year’s “Jul God” passed all tests this time.

“Due to the lack of proper equipment, we didn’t have the chance to detect this earlier, but in a second test it turned out that the CO₂ level was a little too high. As a result, the beer would have foamed. a little too much in the customers’ glasses”, he explains.

Wrong fermentation
Diastaticus is a type of yeast belonging to the genus Saccharomyces cerevisiae. It’s a variation of a standard brewer’s yeast, but it produces an enzyme that can break down complex sugars in the beer, which traditional yeast usually can’t.

This means that diastaticus can lead to fermentation after bottling or cask, which can increase CO₂ levels and lead to excessive carbonation. The result can be that the beer becomes too foamy and even poses a risk of the bottles exploding or burning. Therefore, diastaticus is not desirable in beer production when it is not planned or controlled.