Everything You Want To Know About Scallops
Clean, sweet, and tasting of the ocean, scallops are considered a seafood delicacy by many people. Rich in Omega-3 fatty acids and relatively low in calories, they are an incredibly healthy source of protein.
What I particularly like about scallops is they are very versatile and can be prepared in many ways, from simple searing and grilling to sautéing, deep frying, stir-frying, and baking. I have even prepared scallops in soups, stews, and risotto.
What's In A Name?
As with many delicacies, many stories and traditions have grown up around the scallop. You may have heard the term "Coquille de St. Jacques."
While this names a classic scallop preparation, it also translates to "St. James' shell." St. James the Greater was a disciple of Jesus and is the Patron Saint of Spain.
Pilgrims traveling to his shrine carried a scallop shell to signify they were making a pilgrimage. At stops along the way on his pilgrimage, the pilgrim was offered what food he could scoop up in his shell.
The scallop shell is symmetrical and quite beautiful. It is often found in motifs, both decorative and religious. At some time, the scallop shell was linked with fertility, often appearing in classical art and images of beautiful and desirable women. A notable example of this is Boticelli's The Birth Of Venus.
What Are Scallops?
It is nice to know a little history of the scallop as a symbol of pilgrimage and fertility, but what are they? Scallops are bivalve mollusks. This means that they have two shells.
Although the reproductive organs, or roe, are edible, the part of the scallop that most people in the United States eat is the adductor muscle that opens and closes the shell.
Some people refer to this muscle as "the nut." Unlike other mollusks we eat, such as mussels and oysters, most scallops are free-swimming and can propel themselves across the sea floor several feet at a time by rapidly opening and closing their shells.
Types of Scallops
Three kinds of scallops are consumed in the United States sea scallops, bay scallops, and calico scallops.
- Sea scallops are relatively large, often as many as 1½ inches - 2inch in diameter, and are often presented in beautifully seared platings of two or three.
- Bay scallops are much smaller, although some enthusiasts find them sweeter than sea scallops. Because of their small size, bay scallops are not the ideal scallop for searing but are lovely in stir-fries and even cooked as scampi to be served as a light pasta sauce.
- Calico scallops are harvested off of the US Gulf and Southern Atlantic coasts. Unlike sea and bay scallops, their shells are tightly closed and must be steamed before further preparation. Although similar in shape, size, and color to bay scallops, they are less sweet than their Northern cousins.
Characteristics of Scallops
Speaking of shape, size, and color, the adductor muscle can range from pale ivory to beige. Raw scallops are somewhat translucent and are generally round. Large sea scallops might be up to an inch thick and up to 2" in diameter, while bay and calico scallops, while shaped the same, are much smaller.
How Are They Harvested?
Scallops are harvested in one of two ways trawling or by diving. Trawling is done by scraping the ocean floor and pulling up scallops (and whatever else is down there) without regard to maturity or the damage possibly being done to the ocean floor.
A more environmentally friendly, albeit expensive, harvest method is by a diver giving us "diver scallops." A diver scallop is not another species of scallop, nor does it designate in size. Instead, it describes how the scallops were harvested.
Divers go down and choose mature scallops by hand, leaving behind immature scallops and the ocean floor alone. Since the ocean floor is not disturbed by the divers, diver scallops are usually less gritty than those harvested by bottom trawls.
Day Boat Scallops & STP
Unlike other mollusks that can hold themselves tightly closed once caught, sea and bay scallops cannot and are highly perishable. For this reason, scallops are killed right after harvesting. Some are immediately frozen, while others are brought back to shore to be sold as "day boat scallops," some of the freshest and priciest scallops you can find.
Due to their extreme perishability and the high costs of only taking a boat out for a day at a time, some scallop fishermen treat their scallops with a solution of sodium tripolyphosphate, or STP, which helps keep the scallop from drying out. Used judiciously before freezing, treatment with STP is not necessarily bad.
Unfortunately, when used in great quantity, a soak in STP causes scallops to absorb a lot of excess moisture, sometimes as much as 50% of their weight. Of course, since scallops are sold by weight, this artificially inflates the price.
Buying The Best You Can Afford
If you are concerned about purchasing scallops treated with STP, look for "dry pack" scallops. Dry-pack scallops are packaged without any additives. However, by law, STP-treated scallops must be sold as "wet-pack."
It is pretty easy to tell the difference between dry-pack and wet-pack scallops. While the natural muscle color is generally ivory to beige, and the texture can be slightly sticky, scallops treated with STP are bright white and are very wet to the touch.
Dry Scallops Shrink Less
If you plan to prepare a dish using a dry-heat cooking method, such as sautéing or searing, you will be better off purchasing dry-pack scallops. As you can imagine, a wet pack scallop is more apt to steam in all of that excess water and overcook long before it caramelizes.
And the wet scallops shrink when you cook them almost 40%, whereas the dry scallops do not. So you may be paying more for the dry scallops, but by the time you cook them, you may be saving.
If you are making a dish where the scallop is a supporting player or are using a moist heat cooking method like a fish stew or chowder, you will probably be fine using wet-pack scallops. However, it is a personal decision that you will have to make based on your budget and your feelings about food additives.
How Are Scallops Sold?
Like shrimp, scallops are sold by count per pound. For example, sea scallops might be marked at 10/20, meaning that between 10 and 20 scallops are in each pound. This translates to scallops that weigh somewhere between .8 to 1.6 ounces each. The higher the numbers, the smaller the scallops.
Of course, larger sea scallops tend to be the most expensive. So another weight designation you might see is U/10 or U/15. This means it takes fewer than or under 10 (or 15) to make up a pound.
Here again, the larger the U number, the smaller the scallop. Bay scallops, being smaller than sea scallops, generally fall in the 70/120 range. This roughly equates to between 4 to 9-10 bay scallops per ounce.
When purchasing scallops, make sure to buy from a reputable fishmonger and smell the scallops before purchasing. The scallops should smell clean and sweet and like the ocean. If they have a strong fishy smell, do not buy them.
The muscles should be in one piece, so inspect them carefully. If you see signs of the muscle fibers pulling apart, pass them by, as this is a sign that the scallops are past their prime.
As mentioned, dry-pack scallops should feel slightly sticky but not slimy. If the rubbery side muscle has been left on the scallops, ask your fishmonger to remove them. Trust me; this will save you valuable time in the kitchen once it's time to cook.
How To Store Fresh Scallops
Fresh scallops need to be stored at temperatures below 38F. This is generally lower than most people keep their refrigerators, so you must make some adjustments.
An ideal setup for storing scallops is to have a shallow plastic container with holes in the bottom set in a deeper plastic container.
Place ice in the shallow container and spread the scallops on the ice. Cover everything with a damp paper towel, and store in the coldest part of the refrigerator.
Even with this care, use the scallops within a day or two. Because they are so perishable, using them the same day you purchase them is ideal.
What About Frozen Scallops?
If you purchase frozen scallops, they will keep in the freezer for up to three months. After that, thaw them in the bag in the refrigerator overnight. Again, do not thaw them out on the counter due to spoilage issues.
Do not use the microwave if you find yourself in a pinch and have to thaw your scallops quickly. Instead, run the frozen scallops in the bag under a stream of cold water in the sink until thawed.
Scallops are lean protein and can be toughened very quickly upon cooking. However, it is essential not to overcook scallops as they can quickly go from succulent to a rubber ball.
Please don't take your eyes off them when cooking to ensure that you remove them from the heat when they are still moist, juicy, and plump.
Grilling, sautéing, broiling, and grilling are simple, dry heat methods by which you can cook large sea scallops to showcase them. However, moist heat methods, including stir-frying (with sauce) and simmering (as in soups, stews, and even risottos), are perfect for the small, sweet bay scallops.
great blog with lots of helpful info about the ingredients, tom
Thanks Tom - RG
very interesting and informative
Best information I ever read..great details...I'll have to try the recipes...
Thanks Sean - RG
I hate to hear you are the reluctant gourmet when you have published such a fantastic article on scallops. Really informative and objective--allowing the reader to make informed decisions on the food choice. You also present the material in a simple, concise, easy-to-read way. The only information I missed is that I would have liked more written about techniques like how do you get a proper sear, should you season scallops before or after cooking, how you can tell it is done. I read that we are to not take our eyes off the scallops, but what am I to look or feel for to know that it is cooked properly. Your article was so informative that, for the novice cook, it would have been perfect to have a little bit more information on techniques. Thanks. Already book marked you.
Hi Miss Emerson, thanks for the comment and you are right. I talk about everything scallops except how to cook them. I'll work on a post and link to it from here. Thanks for pointing this out. - RG
Thanks for all the info. One thing you didn't mention that has given me fits is the taste of scallops treated with STP. I guess not everyone is able to taste it, but to me the flavor is so bad that I can't even force myself to eat treated ones. In fact, I almost gave up on scallops entirely before finding out about the difference between dry and treated ones...now I just have trouble finding the dry ones (or even people that know, and/or packaging that's obvious), but Sprouts usually has them and sometimes the local Asian market may. Wouldn't even know where to find a fish monger though...wonder how common they actually are to most areas?
Hi Diane, you must have very strong taste buds or a sensitivity to sodium tripolyphosphate (STP). I have never noticed the taste or has it stopped me from eating scallops although I do notice how much scallops treated with STP shrink when cooking. The problem for most of us, like you, finding dry or day boat scallops is not easy. I would guess over 90% of the scallops we eat at home and in restaurants are not dry scallops so it's important to find good sources in your area. And then when you do find them, you might be shocked by the cost. Here in the Philly suburbs I know of 6 or 7 good fish stores and am starting to see dry scallops show up at many of the supermarkets. If your supermarket doesn't carry dry scallops, try asking them to order them for you. - RG
and, just for the fun of it, I'll add that scallops have eyes---a row of them that can sometimes let them evade the drag of a scallop boat.
Interesting image! - RG
Very informative article in all respects, thanks. Do you know if it's possible to buy scallops with the orange tail (roe) still on in North America? This is the way I'm used to purchasing them in the UK but can't find them anywhere here.....It's just a presentation idea...
Hi Martin, I have never seen or heard of buying scallops with orange roe attached but maybe one of my readers has seen them available. - RG
what does "dry boat' Scallops mean? Is it the same as dry pack?
I have never heard of the expression "dry boat" but instead "day boat" which means the scallops were caught and brought to market that same day rather than after a couple days at sea. "Dry pack" scallops can be purchased fresh, frozen or as I see them in my market, in large sealed cans but they are not soaked in that milky liquid containing the preservative phosphate STP. "Wet packed" scallops are shipped and stored in a liquid containing STP as a preservative. - RG
Excellent article. When you do the article on how to cook scallops, can you also go over how to clean the grit from dry pack scallops?
I agree with Diane. I cannot eat wet pack scallops because they have a funky taste from the chemicals that are used. I gave up on scallops for that reason until I heard about the dry pack scallops. They twice the price as wet pack but in my view, well worth it. It's a treat for us several times a year!
I have a recipe that calls for bay scallops, which I couldn't find. I bought the larger sea scallops instead. Do I just cut them up into smaller pieces to use in the recipe? How big are bay scallops anyway? Thanks!
Hi Celia, I guess you can but why would you. You pay a lot more for the sea scallops so why not use them whole and adjust your recipe. Hard to tell exactly without seeing the recipe but yes you could cut them into quarters if need be. Bay scallops are about 1/2 inch in size and come approximately 40 to 60 per pound but can be as small as 90 per pound. Sea scallops come about 10 to 40 per pound. - RG
I am a cook student. I can't find the answer. Could you let me know what is the best answer. Which size scallop for a coquille St. Jacques?
a. 10 count
b. 30-40 count
c. 40-60 count
d. 60-80 count
Victoria, most of the recipes I see call for bay scallops which are the smaller sizer but I have also seen recipes that just say "bite" size and that if you only have larger scallops, you can cut them up into smaller pieces.
Anyone else have some expert advice for Victoria?
I would use 60-80 size scallops or even smaller. My employer produces Coquille St. Jaques and we use close to an 80-120 size sometimes even 120-150. Hope this helps!
d. 60-80 count, although I prefer a 40-60 count. Usually, they are 70-120 count.
RG: You didn't comment about fake scallops. Unscrupulous sellers are now using skate as a fake scallops and charging a lot of money. The fake scallops are readily recognized by the experienced cook as they are all the same size, whiter than they should be, and don't have the irregular splits in the outer area.
Sea scallops are also known by other names: jumbo scallops, giant scallops, great scallops, king scallops and Alaskan scallops. Most scallops are harvested by net but "diver scallops" are picked individually by divers. It says nothing about their size. Many individuals consider them more environmentally friendly as divers usually pick the largest (and oldest). The usual count is 10-40.
Good points Robert and an interesting topic for another article but if you get to know your fishmonger well, I don't think you will have to worry about fake scallops. Have you ever come across fake scallops? If so, what type of store were you buying them in? Small, large, local, etc. - RG
Your article about scallops is really great.
I have one question about storage. After scallops are purchased, can they be cleaned (from the shell, muscle and coral), then slightly sprinkled with olive oil and stored in the container in the fridge for 1-2 days?
Thank you very much for your response in advance!
Hi I am trying to be a supplier of scallops in Cebu, Philippines but i do not have any idea on how to pack them right. Any advice?
G. Stephen Jones
I do not Phil. A little bit out of my league.
A personal comment about STP and seafood/fish; upon defrosting the seafood or fish, especially fish, I find that the meat turns mushy. The cellular structure of the meat has been broken apart and the excess water leaches out leaving behind an undesirable product. That is my best estimation of what I have experienced. I will pay extra money for seafood not treated with STP and have been rewarded in kind with a quality product when I eat it up!
I really found this web report interesting and it was fun to read and share while dining on sea scallops.
Just discovered this site after using one of your recipes I found on Pinterest. Very informative and helpful. I look forward to exploring further.
Diane S. Walton SELF.
After cooking scallops, how long can I keep them in the refrigerator before they are no longer safe to eat ?
G. Stephen Jones
Not sure of any official amount of time and I'm guessing it depends on factors such as how old were the scallops before cooking, how well were they kept, and how well done were they cooked. Saying that, here is a site that might be useful - StillTasty
thank you for this article very informative. Very helpful. I like to buy scallops wet packed in the 8 pound bucket. I remove just enough for service the day of and the rest I leave in the bucket. This helps preserve a very expensive purchase for a lot more than the two or three days the scallops would last if I dried them out and stored them in the multi container system.
Last night I went out to eat at an expensive seafood restaurant. I got a dish with three very large sea scallops. The scallops were seared and as has happened before, the scallops seemed raw. I am an older individual and while not an expert on scallops, have had them a number of times through my life. Lately, however, it seems they have not been cooked as much as I am used to and I am losing my love of them. They seem almost raw and the taste is lost. Is this something that is happening more in our time period, or am I just crazy?
G. Stephen Jones
I'm sure you are not crazy Linda. I have read if scallops are "healthy", they can be eaten raw. Saying that, like you, I'm not a big fan of under cooked scallops. The question you have to ask yourself and the waiter is if this is how the chef wanted them prepared or did they get under cooked by mistake. If this is how the chef likes to prepare them, you can always send them back and ask them to cook them a little more. I'm sure you are paying a good price for the scallops, so they should prepare them how you like them. Don't be afraid to ask for what you want. You are the customer. Also, if you enjoy eating out and like to order scallops, I would recommend you ask the waiter how they are prepared while he or she is taking your order. At this time you can tell them how you would like them cooked just like you would when you order a steak. We are talking about an extra minute or two of cooking time. No big deal.
Thank you for new information... I love it when I can learn something new!
How do frozen scallops compare to fresh scallops for quality and taste . are scallops frozen at sea better than fresh scallops landed 2/3 days later ?
G. Stephen Jones
Hi Dave, great questions. I think if you can buy fresh scallops right off the boat, they are always going to be better than frozen. Saying that, I'm not sure most scallops you buy at the market are not frozen scallops that are thawed out like almost all shrimp are. I'll ask my fishmonger about this and post when I get an answer. I have read that any seafood frozen at sea is better than a three day back and then frozen. It makes sense to me that if you freeze it at sea there is no time for degradation. I'll ask about this too.
I love dry sea scallops, U15 is what I usually purchase, they come frozen unless I travel to Glen Burnie, Md where the seafood strip is located, they have fresh dry scallops. They are defrosted and dried in refrigerator, dusted with baking powder before searing them with mixture of butter and olive oil. The baking powder makes them crispy because of alkalinity. While they are being seared for a couple minutes, I also add shallot to fry in the butter oil mixture. Then I scoop them aside, baby spinach or baby arugula, toss them in the frying pan where the scallops were cooked, adding extra EVOO as needed, which takes a couple minutes, lots and lots of freshly grated Parmesan cheese.
dish the greens and top it with scallops, the fried shallot squeeze lime or lemon
STP makes the scalp water logged, will not brown as well .
Dusting with baking powder makes them crisp without overcooking,
I love scallops,I make my stepdad seafood Alfredo. he loves it.However bay scallops are twice as as much sweetness than sea scallops.I had them at a restaurant last night,and i was disappointed with the sea scallops. if you all love the sweetness as much as i do, buy the bay.And they cooking minutes.
Linda A Owens
Thanks for sharing such useful information. I have a question: I have never purchased bay scallops, but I plan to prepare a dish (Scallops & Leeks in Cream) that calls for bay scallops. I prepared this dish many, many years ago & used sea scallops, but I'm considering trying the bay scallops. Your thoughts?
G. Stephen Jones
Sounds good. Not sure what you are asking but it sounds like a good recipe.
1. I lived in Australia for 11 years, I never saw scallops offered, cooked or served without the orange portion attached which was always delicious. Why is this removed in the USA?
2. On moving to the USA I read a US govt. publication on sea food. It clearly stated that any scallops labeled as Deep Sea Scallops, are in fact punched out pieces of sting ray or skate. How does one identify which is real scallop?
G. Stephen Jones
Hi John, The orange portion is from female scallops and "is known as the coral and the roe or milt sacs" and yes, it has more actual flavor than the scallop itself. This coral is often removed for sale. It is also removed because this roe is particular delicate and "softens when frozen, so possessor remove it before freezing". Another reason I have heard for removing the roe is for appearance. I read that plated scallops are "aesthetically more appealing without its reproductive organs hanging out to one side."
I am not aware of any US Govt. publication stating scallops punched out of pieces of skate can be labeled as scallops. In fact, I believe it is illegal.