Today I'd like to talk about perhaps one of the strangest organisms that people eat, the geoduck.
Pronounced "gooey-duck." The
word apparently is derived from the Salish words for "genitals," "dig deep," or some combination of the
two.
While I was at home over winter break, my family decided to order some oysters, and the vendor happened to also sell
geoduck.
I had eaten it before many times before, but never had tried preparing it myself.
In Chinese cuisine, geoduck is a highly-coveted delicacy, due its rarity and supposed aphrodisiacal qualities (see
the image below).
In this post, I wanted to give an overview of what exactly a geoduck
Unless you happen to live in the Pacific Northwest, where these unsusual animals grow, it's rather unlikely you'll encounter these without seeking them out. Geoducks are native to and only really found on the west coast of Canada and the northwest of the US (Washington state and British Columbia), though nowadays there is huge demand in China resulting in large-scale cultivation. You can in fact go visit the beaches in Washington and try digging for them yourself during low tide, but there's a mightly challenge of catching them while they burrow into the sand extremely quickly. (For your edifiction, there are some wonderful videos of burrowing geoducks.) Although the typical specimen reaches a few pounds at maturity, there have been some reported at fifteen (!) pounds and three feet in length. Nevertheless, geoducks are closely related to many species of clams more commonly eaten, even if their garguantuan size makes consumption more challenging. Thus, I think it might be helpful to start by discussing the generic class of organisms of which geoducks represent only a single species, the molluscs.
Much of the following information I have taken from Harold McGee's tome
Phylum, more specifically.
Recall perhaps from introductory biology that living organisms are split into domains first (molluscs are
classified as eukaryotes), then kingdoms (animals), and then phyla (molluscs), followed by classes, orders,
etc.
of invertebrates which possess an enormous range of shapes, sizes, and uses.
These contain a large number of what we refer to culinarily as "shellfish," including things from bivalves (clams,
oysters, mussels, geoducks) to cephalopods
(octopuses,
squid, cuttlefish) to gastropods
"Stomach foot."
(escargot, i.e. snails).
The point of this is simply to say that we eat a lot of molluscs, and many of them don't look anything alike.
Undergirding this diversity lies a remarkably consistent body plan which radiated over millions of years of
evolution
Molluscs are some of the oldest
creatures on Earth, having been thought to arisen approximately half a
to produce the range of architectures we see today.
I'll go into a little more detail in the following section, but gist of it is that molluscs possess three major
parts (quoting from McGee here):
p. 223
a muscular "foot" for moving; an intricate assembly that includes the circulatory, digestive, and sexual organs; and enveloping this assembly, a versatile sheet-like "mantle" that takes on such jobs as secreting materials for a shell, supporting eyes and small tentacles that detect food or danger, and contracting and relaxing to control water flow into the interior.
These three parts are reorganized and prepared in various methods for eating. For example, people primarily consume the mantle of octopuses and squid, which forms the smooth exterior of their main body segment, and the tentacles, derived from the foot. On the other hand, with something like an oyster, we typically will consume the entire mollusc. I'll discuss the case of the geoduck in the following sections.
Geoducks don't have a particularly unusual anatomy, as far as molluscs go, but rather the scale is enlarged. The trunk-like appendage which emerges from the shell is in fact a siphon which lends them their fanatical burrowing abilities. If you inspect the siphon closely, it has two holes, one an intake valve and the other for ejecting waste. The large mass inside the shell is essentially the "intricate assembly" consisting of the gills and viscera (reproductive/circulatory/digestive systems) covered by a membranous mantle. Finally, the shell is held shut by a (relatively weak) adductor muscle, which is the part of a mollsuc you would eat as a scallop. Interestingly, because the siphon has to work much harder than the muscles in the body, its texture is more dense and toughens quickly when cooked. This informs the preparation of geoduck, which features primarily raw or fast-cooked methods.
When you first obtain a whole geoduck, its siphon is covered in a rather wrinkly skin and the shell remains tightly
closed if fresh.
Although it may seem baffling as to what you should do with it, turning it into edible state actually is much
simpler than you might imagine.
Chichi Wang has a wonderful description of the simple procedure at Serious Eats: simply
bring a large pot of water to a boil, drop in the whole geoduck for no more than
The siphon, as I mentioned before, tastes best raw, thinly sliced on a bias, and served simply with good soy sauce
and wasabi, but it can also be dressed up into a pretty
The body of the geoduck, on the other hand, is better suited to either short cooking to preserve its tenderness or stewing to break down connective tissue. At Chinese restaurants, the (less-desirable) parts are chopped roughtly and then stewed into congee. The geoduck's chew lends a wonderful contrast to the silkiness of good congee and yields a delicious seafood broth. On the other hand, one can also sauté the body very briefly (no more than one minute, probably) in some butter and white wine or vermouth, as I did, to emphasize its buttery texture and flavor. Serious Eats suggests an Asian flavor profile with chilis, fish sauce, and garlic, which I bet would also taste incredible.
The takeaway is that geoduck is really not that difficult to prepare, despite its terrifying appearance and frequently expensive prices. I hope you've come away with an understanding of these strange and delicious creatures and perhaps even feel informed enough to try one if you get the chance! Thanks again for reading, and as always, any comments or thoughts are greatly appreciated!