Oysters; a Summer Food?

Back, way back, in the days of the late 1700's to the days of the early 1900's the general public protected themselves from eating 'bad' oysters by developing this highly scientific method that seemed to be tried and true.  This 'method' was actually an adage and went something like this; "only eat oysters in months ending with an "R", or months that contain an "R"", depending on where you heard it.   Well, though this adage still has its merits, science and transportation have made it possible for us to enjoy these bi-valves on the half-shell year round, even in the face of many who still cling to the 'old school' ways.  You may or may not be surprised to discover that some beliefs are just too darn hard to let go of.  But, if you want to step into the year 2012, I will let you in on some secret and not so secret information as to how it is possible to eat a raw oyster in the month of July when flowers wilt in the shade and air conditions everywhere quit their day job.

Let's begin with why this adage was necessary in the first place.  During summer months water temperatures rise and different things are going on with oysters and the waters that they inhabit.  We will get to the frisky oysters later, but for now lets focus on their surroundings.    As temperatures rise there is a bacteria found naturally in the water called vibrio vulnificus.  Actually this bacteria is always found in water, usually in the mud and sediment on the bottom, and becomes more active when water temperatures rise.  On the West Coast its cousin, vibrio parahaemolyticus, is also active during the warmer summer months and is often associated with muddy bottoms.  These bacteria can cause a slew of problems most often associated with food poisoning when ingested from eating raw oysters.  As bad as this all sounds, the oyster industry and different State legislation have worked together with scientists and farmers and figured out ways of keeping people out of hospitals and oysters available in raw bars.

On the East Coast, especially around the Chesapeake, starting in May timetables are set by the government as to when oysters can be harvested.  This means that by the middle of the summer oysters must be taken out of the water no later than 8 a.m. and then quickly cooled off for up to 24 hours in walk-in coolers at temperatures below 50 degrees.  These cooler temperatures stop the proliferation of vibrio.   The trucks that transport these oysters must also be kept at this cooler temperature and if the company transporting the oysters is unable to do so, they are not allowed to sell oysters.  On the West Coast, waters are tested every 14 days for pollutants and bacteria.  Barring the 2006 scare, this system is pretty reliable.  Companies are also developing ways in which they can actually track the temperature changes when an oyster is transported (like the coors light cans, only with oysters).  Stickers are placed on the boxes that will actually change color if they reach above 50 degrees.  If the oysters are received in a box where the sticker color has changed, they will be returned.  Another thing we do at BlackSalt is try to buy oysters that are raised in deeper waters, especially West Coast varieties.  Vibrio is found in the muddy bottoms, so if you can source oysters that are grown in deep water columns that are many feet off of the bottom, you can further protect yourself from the chance of purchasing contaminated product.

Spring time is a time of renewal and that is usually the time that Mother Nature starts urging many animal species to get out and go make babies.  Oysters are no different, so as water temperatures change for the warmer, oysters are triggered to get their grooves on.  This time of the year is called spawning season and what it does to the meat is that oysters are so busy spending all of their energy producing offspring that their proteins and fats are burned, making the meat flabby, listless, and far less satisfying.  So it is easy to understand why oysters were shunned during the 'non "R"' months;  oysters needed time to recover and spawn and they just were not as tasty.

This could be July or January.

It shouldn't be any surprise that we have found a way around that too, seeing how wonderful cold oysters can be served on a hot day with a chilled beverage.  A typical, naturally occurring oyster is considered to be Diploid, meaning that it has two sets of chromosomes, and during spawning the egg and sperm each contribute one chromosome to produce a natural diploid oyster.  Through a non-chemical process some oysters have been genetically modified to be what we call Triploid.  Triploid oysters essentially are non-sexual.  They usually will have two sets of one chromosome and one set of another.  They never think about making babies, they just think about eating, making them a good choice for a raw bar year round.  Many hatcheries are now producing triploids on a major scale, especially on the West Coast, and slowly these oysters are making their way to the East Coast as well.  So during summer months instead of playing roulette with diploids you can safely eat a non-spawning triploid and get your fix of quite possibly nature's perfect food.

I am not going to lie, oysters are usually better during their peak seasons; early spring and even better, late fall and early winter.  But, and I can not speak for you, for me, now that I have been spoiled, I could not imagine a world where I had to go without enjoying raw oysters for four months out of the year.  Thankfully because of refrigeration, science, and thoughtful farmers, I won't have to live without tasty oysters during the summer months.  As with anything else, you should only source your seafood products from people who are doing the right thing, which translates; from sources that are checking products diligently and who are familiar with their purveyors.  In today's world a better adage might be ; "When it comes to eating oysters, there's no time like the present."