I’ve lived near the coast of Maine for the majority of my life, yet only recently discovered the edibility of periwinkles. They are everywhere on the rocky coast–in tide pools, clinging onto rocks in the middle of the sea, or at the high tide line. These snails are so copious they almost don’t seem native…because, in fact, they are not.
Periwinkles are native to the eastern side of the north Atlantic, not the western side, and are apparently still commonly eaten in the UK. They were likely introduced to the western north Atlantic by hitching rides on the many boats that made that journey from east to west.
Periwinkles are almost too easy to harvest. Just pick them off of rocks. Transport them in some seawater and save that seawater for cooking. Because periwinkles are herbivorous algae-eaters, humans can consume them during periods of red tide without health risk.
To prepare periwinkles, simply bring to boil enough seawater that will cover them. If you don’t have seawater (which you should, as you were just harvesting periwinkles by the sea no doubt), boil some heavily salted tap water. Once the water is bubbling away, pour in your periwinkles. They only need to boil until their opercula fall off–those hardish “lids” that seem to seal their entry closed when scared. Immediately drain the pot so they do not become overcooked. To eat, use a pin to spear and extract the little corkscrews from their shells. They can be eaten just like that, dipped in butter, or accompanied nicely by a baguette.
A very simple, elegant, and delicious use of a non-native species.