The effects of barley variety, malting, brewing technology, brewer's yeast and bacterial contamination on the biogenic amine content of beer have been investigated. Our results showed that barley variety had a detectable effect on amine content, and this was also reflected in the amino acid decarboxylase activities of the samples. Investigations established that histamine in malt did not originate from barley but was due to microbial contamination. During wort processing, significant increases of agmatine and putrescine occurred, together with decreases for spermidine and spermine. As the histamine synthesising ability of different Lactobacillus strains are quite different, there was no correlation between the histamine level of beer and the bacterial contamination of wort and pitching yeast, respectively. Total amine concentrations of bottled beer are significantly influenced by the brewing technology and to a much lesser extent by the applied barley variety. The histamine content of beer is a good indicator for hygienic conditions of barley storage, malting and brewing, as the histamine content of the product does not originate from barley or from the malt.