Among the 30 or so fish that are called mackerel there are the so-called “true mackerels” like the Atlantic mackerel (scomber scombrus), Spanish mackerels like king mackerel (Scomberomorus cavalla), and many unrelated fish with mackerel like characteristics. Mackerel are smaller and slimmer than tuna but have similar streamlined bodies, forked tails, silver or white bellies and darker, often spotted backs. Mackerel often swim in enormous migratory schools and depending upon their size, act as a predator or prey.
The historically important Atlantic mackerel is still a major food fish, but only make up a small portion of the total catch. Meanwhile two Pacific species, the chub (Scomber japonicus) and Chilean jack mackerel (Trachurus murphyi) are today some of the most important food fishes worldwide.
Mackerel species have fatty, oily flesh that ranges from whitish to dark red with a rich flavor that is not overpowering. There are many ways to prepare fresh mackerel, from very basic to high-end gourmet, but are perfect for grilling or broiling, either whole or in fillets.
There is no hiding an old mackerel, they lose firmness and brightness pretty quickly unless handled well. Look for whole fresh mackerel that are firm and stiff, with a shiny skin and unclouded eyes. If they were not just taken out of the water then they need to be on lots of ice. Flash frozen mackerel can also be found, but quality depends upon how fast the fish was frozen. If choosing “previously frozen” mackerel from a fish counter, the same rules for firmness and color apply. Like other small oily fish, mackerel spoils quickly, which can lead to a serious bacterial infection known as scombroid poisoning if not properly handled.
Due to mackerel’s quick spoilage, they were traditionally pickled, salted or smoked if eaten beyond the immediate coast. Smoked mackerel can be used just like smoked salmon, and with all that good fish oil, has a similar silky taste and texture. Away from the source, mackerel is often found canned in a variety of ways. However, those lucky enough to enjoy freshly caught mackerel know it hardly resembles the canned variety.
When substituting for mackerel look for an oily fish with relatively thin fillets. Herring, large sardines/pilchards, even a light fleshed trout could work as substitutes. Tail or end sections of salmon or steelhead could make a a tasty twist on recipes that call for mackerel fillets.The reverse is true as well, mackerel makes for a good alternative to various other oily fish, from salmon to tuna.
Mackerel Broiled Whole (1852)
[An excellent receipt]. Empty and cleanse perfectly, a fine and very fresh mackerel, but without opening it more than is needful; dry it well, either in a cloth, or by hanging it in a cool air until it is stiff; make with a sharp knife, a deep incision the whole length of the fish, on either side of the back bone, and about 1/2 an inch from it, and with a feather put in a little Cayenne and fine salt, mixed with a few drops of good salad oil, or clarified butter. Lay the mackerel over a moderate fire upon a well heated gridiron, which has been rubbed with suet; loosen it gently should it stick, which it will do unless often moved; and when it is equally done on both sides, turn the back to the fire. About 30 minutes will broil it well. If a sheet of thickly-buttered writing paper be folded round it, and just twisted at the ends before it is laid on the gridiron, it will be finer eating than if exposed to the fire; but sometimes when this is done, the skin will adhere to the paper, and be drawn off with it, which injures its appearance. This is one of the very best modes of dressing a mackerel, which in flavor is quite a different fish when thus prepared, to one which is simply boiled. A drop of oil is sometimes passed over the skin to prevent its sticking to the iron. It may be laid to the fire after having been merely cut as we have directed, when it is preferred so. Large, 30 minutes; 25, if small.