But what's in the bag? And could you make your own? We'll tell you, below... Seafood boils usually contain a combination of allspice, coriander, dill, and mustard seeds. Zatarain's blend is secret (of course), but there's definitely some pepper in there. We've taken a big whiff of the bag before and it knocked us out.
Essentially, it's a super potent bouquet garni — a pouch of flavor that infuses the water while you boil the shrimp.D.I.Y. Recipe: Garam Masala