Changes

When defined species hybridize the resultant yeast should technically be called by the name of both species with a "x" between. A cross between ''Saccharomyces cerevisiae'' and ''Saccharomyces eubayanus'' would be written "''Saccharomyces cerevisiae'' x ''Saccharomyces eubayanus''". In reality hybrids may be more complex than a single cross. Lager yeast is believed to have ''S. eubayanus'' and ''S. cerevisiae'' in its parentage, and it is often known by the name ''S. pasteurianuspastorianus'', although it may not constitute a true species.