Parmesan is a food—but it’s not just a food. Italy’s beloved cheese is often paired with a deep craving for tradition and identity. But its history also involves intrepid immigrants, lucrative businesses and an American version that’s probably available in your local grocery store.

After a notorious debunker of Italian-cuisine myths claims this Wisconsin-made product is the real deal, we embark on a quest to answer the question: Has an Italian delicacy been right under our noses this whole time?

Decoder Ring is produced by Willa Paskin with Katie Shepherd. This episode was written by Willa Paskin and edited by Andrea Bruce. We had production help from Patrick Fort and editing help from Joel Meyer. Derek John is Slate’s executive producer of narrative podcasts. Merritt Jacob is our senior technical director.

Thank you to Giacomo Stefanini for translating. Thank you to Fabio Parasecoli, Ken Kane, Thomas McNamee, Dan Weber, Irene Graziosi, James Norton, and Ian MacAllen, whose knowledge and book Red Sauce: How Italian Food Became American were very helpful.

You should also read Marianna Giusti’s article in the Financial Times. If you feel like really nerding out, we also recommend the 1948 academic study Italian Cheese Production in the American Dairy Region.

We also included clips in this episode from David Rocco’s YouTube channel about how Parmigiano-Reggiano is made and from Gennaro Contaldo’s YouTube documentary on the same subject.

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