In Season: Oysters, clams and mussels at their peak

If you love oysters, clams and mussels, you gotta love February. All three of these delectable bivalves are at their peak of quality right now.

That old saying about only eating oysters during months with R in them was never about the safety of eating them before electrical refrigeration. There was always ice for shipping bivalves during the summer months. In the 19th century and earlier, ice was cut from frozen ponds and lakes and blocks of it were stored, separated by layers of straw, in ice houses across the northern tier of states. The ice would last right through the summer and fall.

The R-month rule simply pointed out when the shellfish were at their peak quality. In the fall and winter months, oysters, clams, and mussels store sweet-tasting glycogen formed from their diet of algae and phytoplankton. They grow fat and sweet until May, when they start their spawning cycle.

By the end of June, the oysters in particular get “creamy.” This light beige sac is full of their gametes - either sperm or egg. It’s more bitter than the glycogen-stuffed meat itself. During the summer, the bivalves, in a mass reproductive event, spill their gametes into the water, sperm meets egg (or vice versa), and the new generation is off and running.

The meat that’s left in the shells is thin and watery - spent of its sweetness. You get a mouthful of salt and not much else. But then as fall arrives, the bivalves start packing in the glycogen again - a process that reaches its peak of quality right about now.

Oyster farmers have a couple of ways around this cycle. It’s relatively easy to grow triploid oysters; that is, instead of the standard two sets of chromosomes, they have three. This makes them a little larger but also reduces their ability to spawn. In addition, oyster farmers can grow the Eastern native oyster, which has a year-round reproductive cycle and so doesn’t lose much quality in the summer.

Clams and mussels do lose quality in months without R, but not as noticeably as oysters. The eastern oyster - Crassostrea virginica - is usually called by the name of the place where it’s grown, such as the impeccable Malpeque from Prince Edward Island, Wellfleet from Cape Cod and Blue Point from Long Island. But when grown here on the West Coast, they’re usually just called the Eastern oyster.

Most of our farmed West Coast oysters are Crassostrea gigas, originally from Japan, brought here in the first half of the 20th century to replace the native Olympia oysters (Ostrea lurida) that nearly went extinct from toxic paper mill effluent in the Pacific Northwest.

Manila clams hitched a ride on the Japanese oysters and have naturalized in our waters, which is a good thing because they are tasty little devils.

Very little farming of Manila clams is done here in California. Most is done in British Columbia and in the Puget Sound region of Washington. However, the Tomales Bay Oyster Co. grows oysters, mussels, and clams in Tomales Bay. Hog Island Oyster Company’s Sweetwaters are Crassostrea gigas, and they grow some Eastern oysters, too. Those excellent Sweetwaters are waiting for you in Marshall on Tomales Bay, at the Oxbow Market in Napa, and the Ferry Building in San Francisco, and they’re plump and fat right now.

This recipe is based on the classic stuffed quahogs (native clams) of the East Coast, but you can use Manila clams or littleneck clams (which are actually baby quahogs) available at Santa Rosa Seafood on Santa Rosa Avenue. If your clam shells are too small to bother with, you can use ramekins or even the cupped side of oyster shells, if you have them.

Stuffed Deviled Clams

Makes 2-3 servings

1/2 pound steamed clam meats (about 2 dozen)

3 tablespoons butter at room temperature

1 tablespoon minced fresh garlic

- Sea salt and fresh ground black pepper to taste

4 ounces chopped chorizo or andouille sausage

¼ cup minced onion

2 tablespoons minced celery

2 tablespoons minced green bell pepper

1/2 cup fine bread crumbs

3 tablespoons reserved clam steaming liquid

2 tablespoon chopped fresh parsley

1/2 teaspoon dried oregano

1/2 teaspoon dried thyme

1/2 teaspoon ground cayenne pepper

1/4 cup grated Parmigiano-Reggiano cheese

Preheat oven to 400 degrees.

Add salted water to a steamer, bring to a boil, add the clams and steam until the shells open, about 5-6 minutes. Discard any unopened clams. Remove the clams to a baking sheet to cool.

When cool enough to handle, consolidate the meats on a cutting board. Pull the shells apart and reserve them. Chop the clam meat finely, or whiz in a blender with a few pulses, just enough to chop, not liquefy, the meat.

In a small bowl, mix together the butter, half the garlic, salt, and black pepper. Set aside.

Heat a sauté pan to medium-high and cook the chorizo or andouille sausage until rendered, about 2 minutes. Add the onion, celery, and bell pepper. Cook about 2 more minutes. Stir in the rest of the garlic, the bread crumbs and the chopped clam meat. Remove the pan from the heat.

In the sauté pan, stir in the clam steaming liquid, the parsley, oregano, thyme, and cayenne until everything is thoroughly mixed.

Pack a heaping mound of the mixture into each shell or ramekin. Place a dab of the seasoned butter on top of each mound, then sprinkle the top with a pinch of cheese. If using shells, place a shell on top and close tightly, tying the shells shut with butcher’s string. If using ramekins, wrap the ramekin with aluminum foil.

Bake for 20 minutes. Unwrap the shells or remove foil from ramekins and serve hot.

Jeff Cox is a Kenwood-based food and garden writer. You can reach him at jeffcox@sonic.net