How do Phyterras yeast prevent the formation of ethyl carbamate?
During fermentation, yeasts break down arginine, an amino acid, into urea and ornithine Yeast cells can then either • further degrade urea into ammonia for a nitrogen source OR • excrete urea. Urea reacts with ethanol + time + heat to form ethyl carbamate Phyterra wine yeast strains favor urea degradation over excretion. Without a urea source, ethyl carbamate can not be formed.
