Escolar: The World's Most Dangerous Fish

Escolar is the most controversial fish that you are likely to find in your fish market. This firm, white fleshed fish has an incredibly rich flavor, often described as 'succulent', or a fattier version of swordfish. Why so rich? It turns out that Escolar's diet contains food high in wax esters. Wax esters that are really difficult for Escolar to digest. As a result, these esters build up in the fish.

Where is the controversy in a buttery, delicious fish? I would say it is in the laxative like effect it has on a certain percentage of the population. Well, a 'laxative like effect' is how my fish monger described it. Others would describe it as closer to diahhrea. An expert would call it 'keriorrhoea'. Literally translated, it means 'flow of wax'. Oily orange droplets pouring out your pooper.  Keriorrhoea occurs because the wax esters in the flesh of the fish pool up in your intestine.

Some reports of Escolar related illness include cramping, nausea, diarrhea, the itis, and other abdominal pains.  This could be the result of severe Keriorrhea or could also be Scrombroid poisoning.  Escolar related Scromboid (or histimine poisoning) is the result of high levels of histidine being converted to histimine usually as a result of poor storage.

Hong Kong Protest Over Oilfish Sale.

Why would you eat a fish that has such terrible downsides? Two reasons:

1. Escolar is delicious. Most likely, the same fatty ester in Escolar that makes you sick also makes it taste so damned good.
2. Taste the danger! If you enjoy a sense of dining adventure, then consider Escolar the log flume of the culinary world.

CROUCHING ESCOLAR, HIDDEN OILFISH
Apart from all of the poop jokes I wanted to make, what really inspired me to write about Escolar is the lack of credible information on the subject.  The Canadian Food Inspection Agency suggests grilling, while Queensland's Health Agency states that cooking method does not matter.  It is really confusing because not only is Escolar sold under other names, but other fish are sometimes mislabeled as Escolar.  Doing some quick google searches, I created the following chart based on all of the references to escolar and oilfish being sold as other fish.  The most common form of Escolar trickery is to be found at your local sushi bar.  Any place selling white tuna or 'super white tuna' is more likely than not selling you Escolar.  White Tuna can technically be either Albacore Tuna or Escolar.  Albacore looks like pale tuna, while Escolar looks strikingly white.

This isn't confusing at all...

There are a number of reasons for this confusion.  Mostly, it is because suppliers and restaurants mislabel fish, either out of ignorance or fraud.  Another reason for the confusion is that Gempylidae, the family of fish that both Escolar and Oilfish belong to, has several other names.  According to Wikipedia, this family of fish is also called Escolars or Snake Mackerels. I have also seen at least one reference referring to Gempyldae as 'Oilfishes'. This means that the family name and the common species name can be the same.  There is also a segment of the population that thinks they were served Oilfish instead of Escolar, and that is what made them sick.  However, I haven't seen much scientific literature to back that up.  Both fish seem to have about equal chances of making you ill.


HOW NOT TO CRAP YOUR PANTS
So I have a couple of quick tips to reduce the likelihood of getting sick from Escolar.  It is mostly gleaned from the Internet, but the most credible source I found was an excerpt of Nick Ruello's Report On The Oil Content, Composition, And The Consumption Of Escolar.

1. Limit Quantity. Obviously, less is more when it comes to Escolar. Conventional wisdom suggests no more than a six (6) ounce portion. I suggest an even smaller amount the first time you try it.
2. Tail portion. While oil distribution varies per fish, the cuts near the tail generally have lower ester count.
3. Cooking Methods. Don't appear to make a difference. There are some sources that claim grilling will reduce the wax esters but there is at least one scientific report that found this to be untrue.  Wax esters are heat stable, so the only potential benefit of grilling is that they somehow leak out of the fish.  This can also be achieved by baking the fish on a rack causing the juices, which may or may not contain wax esters to drip into the pan below.
4. Deep Skinning. With certain fish, this oil resides just under the skin of the fish. By removing the flesh close to the skin, you can reduce the amount of wax ester. While it is recommended to do remove the skin because of its high oil count, there isn't much evidence that deep skinning will help much.  
5. Freezing.  also does not work.  Wax esters are not damaged by cold, even after extended stays in the freezer.
6. Fishmonger Trust. Since there are other fish that also contain high level of wax ester, it is best to go to a reputable fishmonger.  Also, Escolar has some other toxins that can result in histimine poisoning if the fish isn't stored properly.  
7. Pre-Existing Conditions. As always, pregnant women have no fun. Also, people with malabsorption or bowel problems should probably just stay away. Unless you find your bathroom comfortable and you dislike your pants.  

TOO LATE, THE KERI IS O-RRHOEAIN'
I followed most of the advice above the first (and only) time I prepared Escolar at home.  I still had ended up with my own British Petroleum style oil leak, endangering most of the local habitat, with several failed attempts to contain the spill.  If you find yourself in this situation:

1. Well it depends. Actually, no it doesn't... wear Depends. 
2. Replenish your bathroom reading materials. 
3. Call in sick, or plan your day around proximity to the bathroom.
4. Avoid Escolar in the future. The truth is, all you can really do is ride out keriorrhoea. It should only be a couple of days.  

Finally, if you developed a case of Keriorrhoea and you didn't knowingly order Escolar, then you should  think back the the last time you ate a piece of a mysteriously delicious white fish, and give them a piece of your mind... or a stool sample.

NOTA MALE

By now it has occurred to you, that sharing a name with this fish is terrible.  And this is true.  But there is some serendipity between the fish and the author.  We are both simultaneously fatty, delicious, and will likely make you sick to your stomach when we are over-consumed.

If you have had any experiences with Escolar or Oilfish, or found anything inaccurate in this post, leave me a comment.

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