Wednesday, September 29, 2010
Eating raw oysters is a uniquely invigorating experience; a bit like battery-licking for grown-ups. It seems that we can taste the elements they contain: zinc, calcium, copper, iodine, magnesium. And no other food conjures up a physical feature of the Earth as strongly as a bracing, salty, tangy oyster: the essence of the sea in edible form.
Oysters can now be obtained throughout the year but are usually better outside of their spawning period (when the waters are colder).
Shells found on archaeological sites indicate that people were eating oysters 6,000 years ago (how did they open them without an oyster knife?).
For much of recorded history they have been regarded a simple form of sustenance, punctuated by occasional periods in which they reached the status of delicacy. In Britain they shifted from stomach-filler to luxury food with the arrival of the Romans, largely disappeared from the diet after they left, before returning to favour sometime around the eight century.
By Victorian times, pickled oysters were a common food of the poor in London (and in the American South in the early twentieth century the Po-Boy, a type of sandwich featuring oysters in a baguette, fuelled blue collar workers). The era of cheap oysters came to an end quite abruptly after oyster beds became exhausted due to overfishing and pollution.
Oysters are members of the family Ostreidae and the common European oyster is named Ostrea edulis. Oysters are bivalve molluscs found near the bottom of the sea in coastal areas. The upper shell (valve) is flattish and is attached by an elastic ligament hinge to the lower, bowl-shaped shell. Oysters become sexually mature at around three years old and may switch between male and female several times during their life span.
Oysters are high in protein and low in fat. They are rich in zinc and contain many other minerals such as calcium, iron, copper, iodine, magnesium and selenium.
Oysters should be stored at a low temperature and smell briny-fresh. The shells should be clean, bright, tightly-closed and unbroken.
Size, shape and flavour vary considerably. The best from British and Irish waters are considered to be those from Colchester, Whitstable, the Helford and Galway. Natives are pricier and generally thought of as the superior oyster - don't bother using them for cooked dishes. Pacific or rock oysters tend to have a frillier shell and smaller, milder meat.
Unopened (live) oysters can be kept in the fridge, covered in wet kitchen towels, for two or three days - keep a check on them and discard any that open. Do not store in an airtight container, or under fresh water, as this will cause them to die.
Shucked oysters can be kept refrigerated in a sealed container for four or five days. They can also be frozen (previously frozen oysters are better for cooking than eating raw).
Ask your fish seller to open your oysters, retaining the shells (if required) and liquor. If you really want to shuck your own, hold an oyster (deeper shell down) in a hand protected with a work glove or wrapped tea towel. Insert an oyster knife (or wide, short screwdriver) between the two halves of the shell and gradually prise apart, working your way around to the hinge and saving as much liquor as possible. Discard any oysters that are dry or do not smell fresh.
Raw oysters are best with a squeeze of lemon and a pint of Guinness. A drop of Tabasco sauce can be added if desired. Cooking oysters can temper the salty tang and intensify the creaminess of the flavour. Grilling or poaching produce great results in many recipes (see below).
"You needn't tell me that a man who doesn't love oysters and asparagus and good wines has got a soul, or a stomach either. He's simply got the instinct for being unhappy highly developed."
- Saki (Hector Hugh Munro)
Oysters Au Gratin - http://www.seafish.org/plate/d