Editor’s Note:This story first appeared in Dish magazine.
The months of March to October in New Zealand are the oyster season.
BY JOHN CORBETT.
“If you don’t love life you can’t enjoy an oyster; there is a shock of freshness to it and intimations of the ages of man, some piercing intuition of the sea and all its weeds and breezes,” wrote the American food writer, Eleanor Clark. She may have been describing the oysters of the Brittany Coast some fifty years ago, but her words resonate with oyster lovers everywhere.
The months of March to October in New Zealand are the “oyster season”, in which the Bluff Oyster, one of the nation’s delicacies, has a starring role. But it is also a good time for its cousin the Pacific Oyster, because it reminds us that Pacifics are available all year. It’s a good time, in fact, for everybody: New Zealand’s world-leading aquaculture and high levels of water purity result in truly magnificent molluscs.
Oysters and people have a long history. The ancient Chinese were farming them as early as the fourth century BC and Roman emperors are said to have paid for oysters by their weight in gold. The first European explorers to the New World were amazed at the vast middens of oyster shells along the shorelines of North America* and in later centuries oysters were an abundant food for the poor.
“Poverty and oysters always seem to go together,” wrote Charles Dickens in The Pickwick Papers in 1836. How times change.
As well as lore, oysters also have considerable allure, starting perhaps with Aphrodite, the Greek Goddess of Love, who is said to have sprung forth from the ocean on an oyster shell. Or maybe it’s just due to the sheer ambiguity of the oyster itself, which changes sex during its lifetime from male to female or alternates insouciantly between the two. And then of course there’s the sensual taste and texture of oysters – which the French, who know about these things, say are best enjoyed au naturel.
Modern science has revealed that oysters are very good for you. They are a well-balanced food, containing protein, carbohydrates and lipids. They are an excellent source of vitamins A, B1 (thiamin), B2 (riboflavin), B3 (niacin), C (ascorbic acid) and D (calciferol) and are also high in vitamin B12, iron, zinc, copper, phosphorous and other minerals. Recent research has linked their amino acids with the ability to lower serum cholesterol levels. At the same time, oysters are not highly calorific: it’s been calculated that you would need to eat 52,000 oysters to match the calorific value of say, a red deer.* All up, oysters are a veritable cocktail of healthiness, guaranteed to put a twinkle in your eye.
Oysters may not be, as the eighteenth-century gourmand Grimod de la Reynière once remarked, the indispensable opening to a winter breakfast, but winter is certainly the best time of year to enjoy them. In the colder months they are lean and firm-textured, with a bright flavour. In the warmer months they spawn, which alters their taste and texture and often turns their flesh a creamy colour.
How you enjoy oysters is up to you. Steamed, baked, grilled, roasted, sautéed, fried or added to soups and stews, they’re nothing if not versatile. For a simpler taste, just add a squeeze of lime or lemon or a twist of black pepper or a drop of Tabasco, chilli, Worcestershire or Mignonette sauce. Diehard oyster lovers maintain the only way to eat oysters on the shell is au naturel; that way you savour its liquor – the mix of the oyster’s own secretions and the brine of the ocean in which it lives. The French poet Léon-Paul Fargue describes the taste as like kissing the sea on the lips.
*See Mark Kurlansky, The Big Oyster: History on the Half Shell, Ballantine Books, New York, 2006.
Some notes on New Zealand oysters, and buying them:
New Zealand has two species of oysters in good commercial supply – and what we lack in variety is made up for in high quality.
1. BLUFF OYSTERS
(Scientific name Tiostrea chilensis)
Celebrated with an annual Oyster and Seafood Festival in the town of Bluff in Southland and avid seasonal consumption throughout the rest of the country, the Bluff Oyster (or “Bluffie” as it is popularly known) is closely associated with its fishery in Foveaux Strait, but populations also occur sporadically around much of New Zealand. The Bluff is a flat shell oyster (as compared with a cupped oyster like the Pacific) and at up to 10.5cm in size is typically smaller than the Pacific but meaty and full-flavoured. Aficionados regard it as one of the great oysters of the world.
The harvesting of Bluff Oysters is traditionally done by dredging in the open sea. In the last two decades the ravages of the parasitic disease, bonamia, have spurred interest in the aquafarming of Bluff Oysters, to the point where one major Southland producer now bills its product as “wild” to differentiate it from farmed oysters.
Nelson Oysters are the same species as Bluffs, with small fisheries at Nelson and in the Tasman and Golden Bays yielding around 150 tonnes per year. Devotees of Nelson Oysters say they have their own distinctive, flavoursome tang – best appreciated with a good riesling, gewürztraminer or other aromatic wine.
2. PACIFIC OYSTERS
(Scientific name Crassostrea gigas)
A highly successful newcomer, the Pacific Oyster was probably accidentally introduced into New Zealand from Japan in the 1950s, most likely on the hulls or in the ballast water of ships. Adopted by oyster farmers since the 1970s for its fast growth and large size, the Pacific Oyster has since developed premium brands such as Clevedon Coast and Te Matuku Bay and is now exported to discerning markets in Europe, the USA and Asia.
Popular for their plump size and agreeable, mouth-filling taste, the majority of Pacifics are farmed from Northland to the Bay of Plenty and in Nelson/Marborough on intertidal racks. The harvest season runs from around April to late November and is done by hand (intertidal) or by barge (subtidal).
3. THE NATIVE OR NORTHERN ROCK OYSTER
(Scientific name Saccostrea commercialis)
These oysters are found naturally in intertidal zones in the north of the North Island and during the 1960s were commercially farmed. Pacific Oysters have however had a considerable impact on the Rock Oyster population so they are no longer commercially grown. They are a lovely, sweet little oyster though, which the author remembers nostalgically from childhood.
Buying oysters for the table
You can buy oysters in their shells or shucked, but please buy only from reputable suppliers and markets because oysters are filter-feeders and are susceptible to biotoxins. Unless you know what you’re doing, you should also leave shucking strictly to the professionals.
The shell of an oyster should be closed and smell only of the sea. They will keep for a couple of days refrigerated at around 4-6 degrees Celsius, but all oysters are best eaten very fresh. Never put oysters in airtight containers or in water and never freeze them. On the other hand you can happily freeze raw shucked oysters for up to three months and then thaw them in the refrigerator and use as you would fresh oysters for cooking. A tip: add oysters last to a dish as they need little cooking and remember that they are salty by nature.