Consider the Oyster
Oysters are curious, divisive creatures, beloved by some, despised by others. (Here in House Bburi, the split goes evenly down the middle—guess which one of us adores these slimy bivalves?) Oysters have long been the subject of reams of literature in the West, from Lewis Carroll’s darkly humorous poem and Chekhov’s quirky tale of hunger to M.F.K. Fisher’s melodical ode to the oyster. In Korea, too, oysters, or gul (굴), have a long history, with archaeological evidence dating oyster consumption to some 8,000 years ago. During the Joseon Dynasty, oysters were recorded in a 17th century atlas (신증동국여지승람) as an important seafood harvest in seven of the provinces (excluding Gangwon-do). And in 1429, one of the gifts offered to the emperor of the Ming Dynasty was gul-jeot, or fermented oysters.
There are over 100 species of oyster around the world. Korea is home to 14 of them, of which the most common and the only farmed species is the Pacific oyster (Crassostrea gigas), or cham-gul (참굴). This hardy variety with deep cups and heavily ridged shells thrives in a broad range of temperatures and salinity levels, and is particularly resistant to parasites, so they’ve been introduced to other regions of the world (sometimes unintentionally). When they are harvested from the wild, cham-gul are sometimes called seokhwa (석화), or stone flowers, because they cement themselves to rocks on the seabed of shallow coastal waters. On the west coast, oysters can also be found growing wild in shallow mudflats or farmed in netted bags that sit on low racks.
The majority of oysters in Korea, however, come from longline suspension culture along the southern coast. Longline suspension involves seeding wild-caught spat in tanks or shallow waters, allowing the baby oysters to cement themselves to old, repurposed oyster shells. These are then transferred to 5-meter-long ropes that hang suspended from buoys in deeper waters like dangly earrings. In this region of the south, near Tongyeong, the area is known as a “rias coast:” it’s heavily indented with small bays and protected from the open sea by dozens upon dozens of tiny islands. The waters are an incredible shade of indigo blue and are famed for their clarity. According to one source, oysters that are farmed on longline suspension have sturdier shells (easier for shucking) and firmer meat, since they are somewhat more exposed to the elements and have to “hang on” to the line. We learned a lot about oyster farming on our visit to a farm in Tongyeong, which you can hear more about in our segment of Local Eats on the radio program Koreascape. And if you’re really curious, you can read all about Korean oyster aquaculture here.
So this is where oyster production gets interesting: Oysters are very much a product of their environment—so much so that some people even describe oysters in terms of their “meroir,” or terroir of the sea. Oysters can filter up to 50 gallons (190 liters) of water a day, picking up the unique mix of plankton and other particles in its watery home. And like all sea creatures, oysters are sensitive to the salinity of the waters around them—as bivalves, they have a unique way of ensuring their bodily fluids aren’t too diluted or too concentrated (also known as osmoregulation). When the waters around them get saltier, they up the level of amino acids in their cells, including tasty ones like glutamic acid, which give us that gamchil-mat (umami flavor), and glycine and alanine, which elevate sweetness. Plus, water temperatures, salinity, wave speed and more can all affect the rate of oyster growth. In other words, two oysters of the same species can taste wildly different if sourced from different locations.
If you’d like to order some fresh oysters for yourselves straight from Tongyeong, you can contact the farm who generously hosted us here. See Chef’s Notes for tips on choosing oysters!
I used to work in fine dining kitchens in New York City. There, a type of oyster called Kumamoto oysters are very highly prized and usually shipped all the way over from Japan. Kumamoto oysters are very milky and have a very strong oyster flavor. But the same milky, fresh, melon-like flavors so prized in these oysters actually reminded me of Korean oysters. I was a little sad about the fact that Korean oysters were so underappreciated even though they have a very similar flavor. This is actually one of the reasons that brought me to start bburi.
Korean oysters are very memorable, with a distinct crisp flavor in the beginning, creaminess and oceany flavor in the middle, finishing with cucumber-y flavor notes. It also presents you with very plump and meaty flesh, so if it’s your first time trying Korean oysters, you could be a lover or a hater.
how to eat
Koreans eat oysters raw, in muchim (salad), jeon (savory pancakes), steamed, fried, as gul-bap (rice topped with oysters and radish), or soup with maesaengi (link).
how to choose
There are three different ways to buy oysters in Korea:
1. Un-shucked: normally those oysters are not found in local supermarkets, but you can find them at the fish market. They are usually cheaper than shucked oysters. You can also ask the seller to open one so you can examine it. Like oysters on the half-shell, the smell should be fresh and oceany and the flesh should be plump and glossy.
2. On the half-shell: If you go to a big market or fish market, then you can find oysters on the half-shell. The best oysters will be plump and will have a dark black fringe. Make sure they’re glossy, not dried out, and if you can, take a sniff. The smell should be fresh and oceany, and not fishy and off.
3. Shucked: Unlike most of the other countries I’ve been to, buying shucked oysters is the most common way to get them (probably because Koreans like to cook multiple kinds of dishes with oysters, and not just eat them raw only). These oysters usually are found pre-packed in small plastic bags filled with water in supermarkets. Or sometimes you can tell the people at the seafood counter how much you want and have it bagged up there. To get fresh oysters, check the water clarity—if it is starting to get foggy, this means it’s going bad. Look for plump oysters in clean, clear water.
how to clean
If you are cleaning shucked (de-shelled) oysters, you have to use salt water to rinse them. Prepare some salt water (around 3% salinity, e.g., 300g sea salt to 1 liter water)—not too much, just enough to cover your oysters and have a little space to clean them (too much water and you’ll lose flavor). Wash the oysters very gently underwater, looking for any pieces of leftover shell. The main purpose of this cleaning procedure is to clean out any leftover shell bits, so you don’t need to scrub—be gentle!
how to store
If you’ve purchased un-shucked oysters, put them in a container without a lid in a fridge. If you place them in an air-tight container, they’ll die due to the lack of oxygen. These are living creatures! Also, cover them with a damp cloth so that they can have enough moisture and not dry out. If you have oysters on the half-shell, it’s best to eat them as soon as possible, though if you’re planning on cooking them, you can put them in an air-tight container, covered with damp towel to prevent them from drying out and store for about one more day in the fridge. If you have shucked oysters in water, they can generally be stored unopened until the expiration date. But be sure to check the clarity of the water!