Sunday, 30 August 2009

Does an 'R' in the month still hold true?

September is now with us which means very soon it will be shellfish, however, throughout the summer months we are continually asked for Clams, sought after by our Italian customers, mussels by our French, and oysters by our English little interest is shown when trying to explain as to why we don’t have them – ok, but where can I buy some is the response? So is buying and eating shellfish when there is an ‘r’ in the month an issue of safety or quality or both? or if you were to read the Waitrose website neither –“ Whether it’s January or June, you can eat these plump beauties with impunity” (there article also likened Gordon Ramsey face to a craggy farmed rock oyster which I am sure he will be pleased with)

The statement that shellfish are poisonous when there is an ‘r’ in the month still rears its head and it is age old so there must be some truth somewhere. According to the American Centres for Disease Control and Prevention, a full 40% of cases occur from September through April, again dispelling the idea not to eat oysters in the months without ‘r’s in them. Red tides (poisonous algal blooms) that occur in the very hot months do affect the toxicity of the shellfish, however, these are very rare around the coast of the UK. Shellfish filter water through their two shells and feed on the algae and plankton they find in it. What they're grazing on are tiny aquatic life forms called flagellates. The toxins from unsavory flagellates and algae accumulate within the guts of the shellfish – these are responsible for shellfish poisoning.

There are four key shellfish poisoning syndromes associated with bivalves including Clams, Mussels, Oysters and scallops. Paralytic shellfish poisoning (PSP), Neurologic shellfish poisoning (NSP), Diarrheal shellfish poisoning (DSP), Amnestic shellfish poisoning (ASP).

Be aware that no amount of cooking will cleanse a shellfish of it of toxins. Additionally, against popular belief, when a shellfish dies it DOES NOT suddenly become poisonous. You may have experienced a bad clam when cooking which spoils the dish, but this does not automatically mean shellfish poisoning will result. If you or a friend of yours has suffered a type of shellfish poisoning they have just been unlucky. The chef or fishmonger could have no idea that a product he was selling contained toxins. They would have been sold a cultivated or wild harvested product from a supplier that requires a licence to hold their shellfish in a quantity of circulating salt water which has been purified with the aid of ultraviolet light irradiation until the impurities have been removed from the bivalves.

How about quality issues? Our decision not to sell shellfish in the summer revolves around this. Certain shellfish, which brood their young in months without an “r” are less palatable at that time of year. Mussels and clams are empty and small and oysters appear very milky. Native oysters are illegal to harvest in months without an ‘r’. So for us it is the reason of quality – everything has a best season for reasons of taste and texture and when out of season an alternative treat will be in season.

What to look for when buying shellfish?

  • Find a reputable supplier
  • Make sure the shellfish appear damp, shiny and appealing.
  • Make sure all are closed and are not cracked or broken. Shellfish live in the sea and not on a counter therefore occasionally many may appear open or opening. Brush your hand over the top and they should close. If they don’t then avoid them.
  • Personally I would not buy shellfish from a supermarket style wet tank. Bivalves live in seawater with a concentrate of 0.5-35 parts per thousand salinity. They do not live in circulated, chlorinated tap water.
  • Storing - When you have your shellfish at home rinse, drain, put into a glass bowl and cover tightly with a damp tea towel or wet newspaper. Make sure oysters are upright.
  • Don’t store in water – they will die and don’t try and feed them oats (this is my favourite). This is a aged myth and the elderly customers look at me as if I am stupid when I tell them mussels do not eat oats in the sea!

1 comment:

  1. the R in the month I believe was to protect the shellfish in british waters during the breeding season