I'm not a beer drinker, so I honestly never noticed if they do a beer tasting. But as I'm sure you know, they do wine tastings, mixology, tequila tasting, martini tasting, etc. If there's not a beer tasting seminar, I'd be really surprised.
P.S. -- just looked at the DCL site. Diversions (Wonder) and O'Gills (Magic) both offer beer tasting on sea days. I can't find specifics for the Dream and Fantasy, but it seems to be a safe assumption that they'd do the same.