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Information from Don Kasarda, Albany, CA
 
We have started doing a little research on gluten peptides in beer and find
it a very difficult area of research.  However, it has caused me to read the
past literature more carefully, understand it better, and also to
communicate with other researchers.
 
One point that might be of interest is that, according to published work in
which an antibody to a peptide derived from alpha-gliadin was used as a
probe (Julia Ellis et al. in the UK), a pint of barley-based beer contains
the equivalent of about 1.5 mg of gliadin.  Another researcher tells me that
he has found a similar amount in Danish beers brewed from barley, but much
more (about 30 times more) in wheat-based beers (weissbier).
 
I think these results seem reasonable. However, it is possible that further
research may up the amount somewhat, but also might decrease it substantially.
As I said, the analysis is quite tricky and more work needs to be done to
substantiate or change the results obtained to date.