Fresh Oyster Types
John McCabe

Fresh oyster are sold in three ways: Shell stock, shucked, and HPP.

* Shell stock (or shelled stock)
Shell stock is suited for half-shell (raw) consumption and for cooking.
These oysters sit inside the seafood vendor's case, complete (shells and all) and are very much alive (hopefully). They are usually sold on a piece count basis.
In North America, the shell stock oysters sold over the counter are vastly dominated by two species: Eastern oyster (Crassostrea virginica) and Pacific oyster (Crassostrea gigas).

Inset image: From left to right we observe the Eastern oyster (Crassostrea virginica), the Kumamoto oyster (Crassostrea sikamea), and the Pacific oyster (Crassostrea gigas). The Eastern oyster pictured on the far left measures a tad over 3 inches (8 cm) in length. This oyster species is the classic (North) American oyster and dominates oyster sales on the East Coast and the Gulf. The State of Louisiana is the largest producer in the world. The little Kumamoto oyster in the middle is a West Coast product. The State of Washington is likely the largest producer in the world, although it originally hails from Japan. It is considered a desirable specialty oyster. The Pacific oyster on the far right is the king of the West Coast. The State of Washington is the largest producer in North America. China is (by far) the largest producer in the world.

The ball park price (2006/2007) at seafood markets runs anywhere from 50c (a great bargain if truly fresh) to 2 bucks a piece (high). Occasionally you may also find the European oyster (Ostrea edulis) and Kumamoto oyster (Crassostrea sikamea) for sale. Although they are a tad more expensive, give 'em a try at least once if you've never tasted them. You might be very pleasantly surprised. If you really get lucky, you might spot the tiny Olympia oyster (Ostrea lurida a.k.a. O. conchaphila) in the seafood case. Don't let the small size of the Olympia oyster fool you. It's a proven winner when it comes to "heaven on the half shell".

Inset image: The small Olympia oyster (Ostrea lurida a.k.a. O. conchaphila) is a native West Coast oyster. The State of Washington is the largest producer in the world. It is remembered as the "Gold Rush oyster" as some 49ers once paid a silver dollar for just one. It is tiny, rare, and rather expensive - and worth it.

The three specialty oysters mentioned control a comparatively small share of the North American oyster market. They are generally slurped raw off the half shell. They do, however, also excel in oyster recipes by adding an exciting dimension in taste.

In Europe, the Pacific oyster vastly dominates the shell stock sales. The pricey European oyster accounts for but a tiny fraction of the combined European oyster volume.

Inset image: The Pacific oyster is located on the left. The pictured specimen measures about 4 inches (~ 10 cm) in length. The European oyster is located on the right.

Pointer: If you are buying oysters in the shell, you'll need an oyster knife later at home. Even a cheap one is better than no oyster knife at all. If you don't own one, you might consider buying one while you're still at the store buying oysters.

Another pointer: If you are buying these oysters for "half shell oyster fanatics" (like me), consider also buying some dry (!) white wine or some beer - perhaps even a type of beer for a change that is a step above the common "cheap suds". Just because the oysters are very affordably priced does not mean that they are not a true luxury food of the first order, fit for kings and queens. In most cases it took at least two to three years to grow this delicacy - in any case about as long as it takes to produce a better grade Champagne. Champagne incidentally also goes well with raw oysters. Choose those with no or low "dosage" (a small amount of a wine and sugar mix that is added to enhance Champagne). Classifications like Brut integral, Ultra brut, Extra brut, Brut, and Extra dry all work very well with oysters. Sec, Demi-sec, and Doux do not complement the taste of oysters well.

Also remember to pick up some lemons and a bottle of hot sauce. Many oyster lovers like a few drops of lemon or hot sauce on their oysters. The lemon is cut into thick slices which can then be halved or quartered (wedges). I like serving wedges, one or two every two oysters, as only a few drops of lemon juice suffice. If you feel a little adventurous, then pick up a lime too. A few drops of fresh lime juice also work very well with oysters - some say better than lemons. In any case, mixed lemon and lime wedges look pretty on an oyster platter. Buying lemon juice in a bottle is only a last resort if no fresh lemons are available. Although Tabasco sauce is always a good choice with oysters, there are many other hot sauces that are also excellent. While I think of it: Pick up a little fresh parsley to dress up the look of the oyster platter. Shock your friends by eating a fresh sprig of this "garnish". Parsley is delicious and healthful.

Another pointer: When you buy shell stock from a seafood vendor, you usually will not know how fat that oyster is inside that shell. The shell size is no indicator, as the shell of a skinny oyster can be just as big a shell of a fat one. Consolation: No matter how fat or skinny the oyster inside turns out, it will always taste great as long as it has been permitted to retain its natural moisture level (not dried out) due to proper handling by the grower, shipper, and ultimate seafood vendor. Naturally oystermen are well aware of the fact that shell size is no sure fire indicator of the actual meat weight of oysters. Without exception, every oysterman strives to produce the fattest, best tasting oysters possible in the oyster bed(s) he controls. Unfortunately the sea and his oyster beds actually control him instead. In some years, his bed(s) will produce exceptionally fat oysters; in others the oyster meats will be rather skinny. Many small growers sell their shell stock to big growers for meat processing. The big growers will pay these small growers based on actual or prospective meat weight yield. Many growers work extra hard to insure fat and tasty oysters by shifting all their oysters at a certain size from one oyster bed to another. The other bed has traditionally produced fat and tasty oysters in most years. This is due to a naturally high level of nutrients that the oysters can then feast on for a year or more. These beds are called "fattening beds". Many small growers, however, do not have the luxury of additional fattening beds that they can rotate their stock on. The oyster business is a very hard road for many reasons. Please support your oystermen.

Just one more pointer: Some epicures subscribe to unwritten rules regarding the shape of a Pacific or Eastern oyster destined for serving on the half shell. The highest grade describes any oyster that is no more than 1.5 times as long as it is wide. Up to 2 times length vs. width describes an acceptable standard size. Any more than that is deemed "commercial", better suited for meat processing. Many growers go through much trouble trying to produce oysters with perfect shell shapes. Some rotate their stocks to firmer sea bottoms. Others employ tedious cultivation methods in mesh bags (called rack and bag cultivation). Hence, a favorable "choice" or "standard" oyster shape sometimes commands a premium price in the half shell trade.

* Shucked oysters or "oyster meats"
Shucked oysters are also considered fresh (although the oysters are already dead). They are very convenient as there will be no mess or fuss with opening oysters. The grower/producer has already removed the oyster meats from the shells (a process called shucking). Then the meats were thoroughly washed with chilled water. After the cleaning process they were filled into jars. Ten and 16 ounce jars are consumer favorites. Containers holding a gallon or more shucked oysters also exist. The amount of water that may end up remaining in the jar is limited by law. The milky "juice" with the meats in the jar is excellent cooking stock (so called "nectar", as much of it constitutes the milky looking oyster blood). Shucked oysters are fabulous for cooking. About half of the great oyster recipes out there use the pint measure for the quantity of oysters required (instead of piece count of required shell stock oysters). The small oyster meats are also ideally suited for creating oyster shooters - something every restaurant and bar serving shooters has known since day one. If you've been tipping your bar keep extra well after being served tasty oyster shooters because you thought somebody in the kitchen battled with the shell fortresses of some oysters just for you in the kitchen, think again.

In North America the Pacific oyster and Eastern oyster vastly dominate the shucked oyster retail business. The Kumamoto oyster and Olympia oyster are also available in this form occasionally. I've never seen European oyster meats for sale - only shell stock. They are almost exclusively slurped off the half shell. In Europe the shucked oyster market is very slim at best. Shell stock vastly dominates the market.

As mentioned, shucked oysters are usually sold in pint and gallon sized plastic jars. They are perishable and marked accordingly with a date. Read the date and the instructions on the jar label. The Pacific and Eastern oyster meats are organized by size. Usually the sizes are small, medium, and large. Please note that a "small Pacific oyster" is bigger than a "small Eastern oyster" (see ref. below on the respective sizes). Sometimes you might run across x-small (a.k.a. "petite" or "bistro") and x-large. Small oysters are more expensive because it takes many more oysters to fill a pint - and somebody, somewhere, had to stand there and carefully open each fresh oyster with an oyster knife. Kumamoto oysters (a.k.a. "Kumos") and Olympia oysters (a.k.a. "Olys") are always small, so any size reference is actually a waste of label space. It takes about 250 Olympia oyster meats to fill a pint, 2,000 to fill a gallon.

Pointer on Pacific and Eastern shucked oysters: If you plan to create a big oyster stew or some other tasty oyster dish that simply requires lots of oysters of no particular size and shape, ask the vendor if he or she also offers so called cuts. These are oyster meats (mixed sizes) that were damaged during opening at the grower's shucking facility. They also come in pint and gallon sizes and are usually considerably cheaper - and taste exactly the same.

Measures and Weights
What follows are a few boxes referencing how shucked oysters measure up per pint (16 oz). Additionally I listed two small boxes showing how shell stock is handled in Europe (shucked oysters only have a miniscule market share in Europe):

North American Pacific oyster

Abb.	XS	S	M	L	XL
Quantity	18+	12-18	8-12	<8	***

North American Eastern oyster

Abb.	XS	S	M	L	XL
Quantity	63+	38-63	26-38	20-26	<20

Abbreviation key: XS = Extra Small; S = Small; M = Medium; L = Large; XL = Extra Large
Reference: Oysters, A Connoisseur's Guide & Cookbook; Lonnie Williams, Connie Warner

European shell stock reference: Pacific oyster

Number	5	4	3	2	1	0
Abb.	P	M	M	G	TG	TG
Weight	30-45g	46-65g	66-85g	86-110g	111-150g	150g+

Abbreviation key: P = Petit (small); M = Moyen (medium); G = Grand (large); TG = Très Grand (extra large)
Source: http://www.huitresmarennesoleron.info

European shell stock reference: European oyster

Number	4	3	2	1	0	00
Abb.	P	M	M	M	G	TG
Weight	40g	50g	60g	75g	90g	100g

Abbreviation key: same as above
Unusually large (and rare) European oysters may further be qualified numerically as follows: "000" = 110g, "0000" =120g, "00000" = 150g and beyond.

* HPP (High Pressure Processed) oysters
HPP oysters are something fairly new among fresh oysters. Only relatively few stores offer them at this point (they are also available online). The Nisbet Oyster Company (a.k.a. Goose Point Oysters) in the State of Washington boldly pioneered this type of fresh oysters a few years ago. High hydrostatic pressure (40,000 lbs per square inch) is applied to oysters (in the shell) submerged in water. The pressure destroys any potential bacteria and simultaneously separates the adducter muscle of the oyster from the shell. This leads to great convenience, increased food safety and shelf life without sacrificing any of the oyster's natural taste or changing its appearance. When I first heard of these "HPP oysters" I had my doubts - until I tried them. They tasted great. The only problem I had was inside my head. I was so used to gallantly fighting oyster fortresses with my trusted oyster knives rather than simply cutting a little plastic band to get at a fresh oyster inside. The idea of oyster meat already perfectly shucked inside the shell just struck me as "rather strange". I quickly got over "my problem" though after consuming a few of these delicious "HPPs". Try some if you get a chance.

General pointer: There is nothing wrong with asking the local fish monger about the possibility of special ordering a particular type of oyster he may not carry regularly.

* Intro
* Fresh Oyster Types
* Looking over the Seafood Display (and Who's behind it)
* LiFo (Last in, First out) Shopping
* How many Oysters to Buy
* Buying Oysters on the Internet