I'm not sure anymore which grains have phytates, but most of them
do--certainly wheat, rye, and barley.  Rice, possibly not, I can't recall.
Basically, it's in the husks, what we call the FIBRE.  The phytates are
present whether you cook the grains or not.  Refining carbohydrates will
get rid of them, which perversely means that highly refined flour products
like Wonder Bread or beer are less of an issue than, say, a slice of whole
wheat bread.  But of course in those cases you're paying the price of what
highly refined, nourishment-depleted carbohydrate foods like that do to you.