Recently, the question came up about whether or not blue-veined cheeses are gluten-free. It's a fair question to ask, given that blue cheeses (Roquefort in France, Stilton in England, Gorgonzola in Italy, Danablu in Denmark, and Maytag Blue in the U.S., for example) are made using mold derived from the Penicillium bacteria. That mold, in turn, is traditionally and historically grown on bread as the substrate. And bread, of course, means gluten. Right?
In instances where bread was used to grow the mold, yes, gluten could (and did) find its way into the cheese. Nowadays, for artisanal blue cheeses still made according to historical guidelines, gluten remains a concern, and not all blue cheeses are gluten-free.
However, today many (if not most) blue cheeses are gluten-free, by virtue of the fact that the molds are now developed in a laboratory setting with a chemical substrate free of gluten. So, to offer three examples (hardly an exhaustive list), the Bel Gioioso cheeses, Point Reyes cheeses, and Rosenborg cheeses are all gluten-free. And there are many others.
If your favorite blue cheese company doesn't have a gluten statement on their website, your best bet is to check with the particular company that makes the cheese in question – they would be able to definitively answer whethere or not the cheese is gluten-free. While more and more companies are making gluten-free blue cheeses, not all do, and so the safest route is to ask. The fact remains, though, that most blue cheeses will be gluten-free. So if blue-veined cheeses are your thing, rejoice!
(Thanks to one of our readers, Mike, for writing in with the question!)