Off-tastes and odors are produced most often by wild yeast (e.g. Sacc. cerevisiae and Sacc. pastorianus), lactic acid bacteria (e.g. Lactobacillus and Pediococcus) and oxidation. In addition, strictly anaerobic Gram-negative bacteria including Pectinatus cerevisiiphilius and Megashaera spp. are becoming more and more important as beer spoilers.
Addition of Natap™, White NisinA™+ can be used as natural preservatives for a protected shelf life of beers.