Opening Oysters


Classic Method
Clever Method
Commercial Method
Clumsy Method
Oyster Knives

Screwdrivers, Hammers, Pliers, and Better Mouse Traps
John McCabe

What follows is an overview of a few ordinary hand tools used by some folks to open oysters as well as a closer look at some related professional and kitchen ware tools. Tools that are pulled right out of one's tool box are entirely out of place when processing food - particularly when preparing a delicacy like oysters. Besides tools, a tool box frequently harbors residue from motor oil, grease, rust, paint chips, tiny metal fragments, and lots of other "incidental stuff".

* Screwdrivers
A flat-head screwdriver is likely the most common conventional tool used to open oysters. It does work. Both the classic method (entry via the hinge) and the clever chipping method will quickly open the oyster. I used a skinny flathead screwdriver for years. One fine day I skewered my left hand with it. I choose to reflect back on that annoying week during which my left hand was out of commission as a time of enlightenment. I "brilliantly" deducted that the "screw" part in the word "screwdriver" actually has something to do with screws - not oysters. Ironically, up to that point, I had always been the one to preach "Performing a good job presupposes using the right tools." I then went out and bought a good quality oyster knife - and later wondered how I ever got along without it.

* Hammers
Besides the proverbial "when all else fails..." carpentry claw hammer, there are several other types of hammers that are certainly noteworthy in the context of oysters. All of them have one thing in common: They are used for cracking and chipping, never smashing!

Conventional (Claw) Hammer
In terms of opening oysters, the conventional carpentry claw hammer is probably still the most commonly used hammer style. This phenomenon may, at least in part, be due to what some might have interpreted as a form of governmental endorsement of this crude instrument as an "oyster tool" ("... a method preferred by some cooks"). In 1964, the U.S. Bureau of Commercial Fisheries issued a booklet on oysters. It had been reissued numerous times since 1953 and was part of a series of booklets on the preparation of fish and shellfish. All of the booklets were exceptionally well done. In the oyster booklet, the use of a conventional carpentry hammer was shown for "billing" the oyster (inset picture) and the subsequent use of an oyster knife was advised to cut the adductor muscle inside. The clumsy hammer is entirely superfluous (and one more tool to clean), as a quality oyster knife will perform both tasks just fine (as described in the clever method).



If, for some reason, the use of this hammer type is deemed indispensable, perhaps a small ball-peen hammer (instead of a claw hammer) might be considered instead. The head of the hammer should be unpainted. It should then be dedicated solely to food preparation purposes and never end up out in the tool box. The face of the hammer (not the ball end) is used. It may also come in handy for other types of shellfish (like crab).

A so called cross-peen hammer is even better. It has a horizontal straight edge (instead of the ball) on one side. Both the face and the edge side may thus prove useful in the kitchen.

The so called straight-peen hammer can also serve nicely in the kitchen, not only as a crab or oyster helper, but also with tasks such as breaking tough bone ligaments on meats. Unlike the cross-peen hammer, the straight-peen hammer has a dull hatchet like edge which runs in line with the handle. After use, hammers should be washed and oiled with a little vegetable oil to help prevent rust.

Crab Hammer (a.k.a. Crab Mallet)
Crab hammers (frequently also called crab mallets) may be the best hammer style of all in terms of seafood preparation. Usually they are rather small. The round or square head commonly measures about two to three inches wide and the combined length of the tool amounts to approximately seven or eight inches. Besides operating these little hammers with the handle, some designs also allow using the head as an excellent grip, thus turning their special handle into an additional tool.

The functionality of these little hammers is certainly not limited to just crabs. Besides other types of shellfish, they can prove to be a rather handy kitchen tool when preparing quite a number of other foods.

Crab hammers can be made of a pewter alloy (like the famed Wilton crab hammers), all hardwood, stainless steel, or some combination of hardwood and metal. Pewter never rusts. However, it is considerably softer than steel, even as an alloy. Hence, the pewter handle should never be used as a prying tool, as it may bend. Wooden crab hammers also work well. They are comparatively inexpensive. Much like the wood of cutting boards, they may expand and contract and ultimately crack if left uncared for in a moist state. Since wood is porous, it can also harbor bacteria and attract mildew. Hence, wooden crab hammers, right along with wooden cutting boards, should be cleaned properly after use with a light water/bleach solution (2 parts water and 1 part bleach) and dried. Some of the wooden designs also feature a convenient hatchet like edge on one side (similar to the straight-peen hammer pictured further up in this text). The handles are round and functionally serve no purpose other than what is expected of any typical hammer handle.

Most metal crab hammer designs work particularly well on oysters. Besides using the head in a chipping or cracking manner to create an opening along the edge of the oyster's bill, it can then switch to being the handle of an effective blade. This "blade handle" can then be inserted in the opening to cut the adductor muscle within the oyster.

Image left: An older crab hammer with a pewter sleeved hardwood head and a stainless steel handle. It was made in Japan (perhaps in the 1960s or 70s) without a manufacturer's name. It has a crab imprint which is identical to the one used in the Wilton pewter crab hammers (pictured above). Although the shape and size of this crab hammer is almost identical to the commonly found American pewter hammers, it is considerably different. The head is made of some type of hardwood which is sleeved by a pewter band. The "handle blade" is made of fairly thick stainless steel with tapers down to a rather dull, flat and rounded tip. Aside from being rather attractive looking, it is also one tough tool - much like an oyster knife with a "T" handle. A large oyster can be billed and shucked within seconds with this particular fellow - without ever using the hammer head. I don't bill oysters with the handles of pewter crab hammers. Pictured ruler measures in centimeters. Hammer length 17 cm or 6 3/4". Head width 5.8 cm or ~ 2 1/4". Head diameter at ends 2.6 cm or ~ 1". Weight 5 oz. Dimensionally, the famous pewter Wilton hammer is quite similar. The older one I have has a length of 16.5 cm or ~ 6 1/2". Head width is 5.5 cm or ~ 2 1/4". Head diameter at ends 2.6 cm or ~ 1". Image of an older Wilton can be viewed by clicking here.


* Other Hammers

Culling Hammers
Culling hammers are not used to open oysters. On the contrary: They are precision tools used in a process called culling, the skillful and delicate work associated with separating individual oysters from oyster clumps. More on culling hammers in the commercial opening section.

Crack Hammers
Small, all carbon steel hammers called crack hammers were once used in some commercial shucking houses to knock off a piece of the front of the oyster (the so called bill) to more easily gain access to meat inside with an oyster knife. Frequently a special "cracking block" or "oyster shoe" held the oyster in place. A so called crack knife was also used in this process (pictured under knives). Crack knives are heavy. They were machined out of a piece flat carbon steel bar stock (usually about 8" long). The handle ends of these knives, where the crack hammers impact, are the flat ends of the original steel bar stock (usually ½" x ¾"). Today, the commercial use of crack knives for opening oysters is considered an occupational safety hazard.

* Pliers
The use of a pair of pliers to open an oyster is also recommended by some folks. Unlike the "hammer method" which addresses the side margin of the "bill" in the government booklet mentioned above, the pliers are applied to the front of the bill. An attempt is made to snap off a chunk of the upper and lower shell halves and create an opening where a knife can then be inserted to cut the adductor muscle inside. Although it does work, it can be a real pain in the "you know what" on large oysters. Since oyster shells, particularly large ones, are remarkably tough, it is best to "nibble away" pieces until a sufficiently large hole for the knife blade is evident. Essentially, the "pliers method" is a clumsy variant of the commercial method, as the commercial method also aims to remove a shell chunk from the front of the bill - with an oyster knife of course, not a pair of pliers.



"Better" Mouse Traps

"Automatic" Lever Action Devices
A review of clumsy oyster opening methods would not be complete without mentioning the "automatic" lever action oyster openers. To the best of my knowledge, various models of these devices started popping up in the market place in the 1970s, probably right about the time Dan Aykroyd presented the truly amazing "Bass-O-Matic" on the Saturday Night Live TV show.

The device pictured is called a "Safety Action Oyster Opener". Not included: The pen, merely for size reference, the screw driver (we'll get to that), and the victim (a medium Pacific oyster). It features a varnished wooden base measuring 5 x 7". A groove, approximately 3 ¾" long, 1" wide, and ¼" deep was hollowed out lengthwise. An upside down V shaped bracket (about 3 ¾" tall, stainless) in the forward section, mounted on the wood with two ¼ hex head screws, serves as the hinging sector for a flat stainless bar with a round wooden handle on the end. The bar is about 1/32" (1mm) thick and approx ¾" tall (handle part 1 ¼ x 3"). The bar and handle measure about 8 ½" long and hinge on what appears to be a brass alloy rivet at about the 2 ½" mark on the upside down V bracket. A strong steel pin with a point, about ¾" long is welded to the rather thin bar, on the underside and perpendicular, just short the half-way point between the bracket and the beginning of the handle. With the bar held up to where it is positioned horizontally and parallel to the base, the point of the pin aims at the hollowed out groove below at the beginning of the forward 1/3 of the groove. This is where the oyster will be pierced by the point of the pin, hopefully right between the shell halves while it is held down on its edge in that wooden groove. The entire nifty device comes in a 9 ½ x 5 x 5" box and includes an interesting piece of paper titled "Directions for use".

The "automatic" oyster opener immediately charmed me with its obvious mechanical simplicity and I was most anxious to put it to work. Although I suspected the use of it to command little more intelligence than required to operate a conventional paper cutter, I decided not to fall victim to the old adage "when all else fails, read the instructions". I'm glad I did. I was instructed to position the oyster on the base in that groove and to bring that point down on "any of the three sides away from the hinge end… It is important at this stage to probe these three sides for the true dividing line between the shell halves. Nature has provided the oyster with a series of apparent edges or dividing lines, only one of which is the true one. Practice makes perfect." Hence it did not matter if that point pierced the shell divide on the side of the adductor muscle, on the bill, or the side away from the adductor. I was then advised to apply firm downward pressure on the handle with the opener point placed at the "most likely line" between the shell halves. Either the oyster would then open rather easily or I would have to try again until I find it. Bottom line: That part does work and the pin indeed pries open a gap between the shells. Now what? The adductor muscle of the oyster is still hanging on for dear life and the hinge has not relented. Another look at the instructions furnishes the answer: "As soon as the two shell halves start to separate or shift sideways under pressure from the opener, insert a common screwdriver into the opening and with a twist of the wrist(,) hinge will break and oyster will be open." The oyster essentially ends up being ripped apart by the shell halves - not elegant by any stretch of the imagination and certainly not very automatic. Despite appreciating the irony at hand, I didn't really like being asked to go out and look in my dirty old toolbox for a "common screwdriver". I thought the screwdriver days of opening oysters were over. This new "thing" was supposed to open the oyster. I don't need that "thing" because I already know that my flathead screwdriver alone will open any oyster via the hinge. Needless to say, I will try to resell this device at my earliest convenience as "only used once".

Pull Tab Oysters
A couple of years ago I ran across a European news blurb advising of a new way to open oysters. Some enterprising guy had figured out a way to insert a thin piece of stainless steel or nylon wire between the shell halves of a living oyster, then somehow loop it around the adductor muscle and then feed it back out of the oyster. The ends were then tied into (or attached to) a loop or pull. Lots of fresh oysters with convenient little rip chords hanging out of their shells could then be offered to the public. The design is somewhat reminiscent of pull tabs on soda pop cans or a garrote of some sort. All the consumer needs to do is yank on that loop which then cuts the soft adductor muscle inside the oyster and - voilà! - it's open. Oyster knives would be rendered obsolete. Well, actually not quite obsolete as the rip chord would certainly sever the adductor muscle, yet leave at least one substantial portion of the cut adductor muscle firmly attached to the shell. Hence it would first need to be cut from the shell before the oyster would be ready for slurping. I'm not sure if the idea ever caught on. I suspect it did not.

Update (Jan. 12, 2008): Looks like the oyster pull tab idea is still alive in France. Picture of one of these "pull tab" oysters:
French website describing this "oyster magic":

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Health advisory: There is a risk associated with consuming raw oysters or any raw animal protein. If you have chronic illness of the liver, stomach, or blood or have immune disorders, you are at greatest risk of illness from raw oysters and should eat oysters fully cooked. If you are unsure of your risk, you should consult your physician.

Advisements on any errors discovered are most welcome: Contact