[Baby Salmon (marketing); Oncorhynchs mykiss]
Some Rainbow Trout stay in the lakes and rivers and are rainbows their entire lives. Others, even from the same batch of eggs, are rainbows for only for only one or two years, then lose their rainbow coloring and head out to sea to become Steelhead. A year or more later they return to the river of their birth to spawn, regaining their rainbow color. After spawning they turn silver gray again and head back to sea.
Nobody knows why some rainbows join the Navy and others stay at home, but those that do go to sea grow larger, live nearly twice as long (to 11 years) and spawn over twice as many times (to 8 times). Steelhead can exceed 40 inches and 50 pounds but most are nearer 24 inches and 8 to 11 pounds. They are considered threatened by habitat destruction.
At sea Steelhead eat a diet similar to what salmon eat so they take on
the same orange-red color. Fish farms are now producing ersatz steelhead
by moving rainbows to salt water pens. These may or may not be fed dye to
produce a salmon color. The farm raised photo specimen was 27 inches long
and weighed 6.91 pounds factory cleaned. It's flesh was not noticeably
Photo © ch1.
Please Note: The information here is based on a single sample of farm raised steelhead. It is not likely typical of wild steelhead - but your chances of getting one of those are probably remote. Farmed steelhead are becoming rather common.
Having bought the large and fine looking specimen shown in the photo, I was looking forward to an enjoyable fish dinner - but ended up eating corn on the cob instead. The flesh was too tender to cook by most methods and rather insipid in flavor as well. I did broil and eat the skin for breakfast and snacks the next day, but the flesh I rolled up into lumps and froze for use in making fish balls and patties, a use for which I expect it to be quite suitable.
Buying: Farmed steelhead are now common in Asian fish markets in Southern California, always labeled "Baby Salmon". The photo specimen was factory cleaned, but with the gills still in.
Scales: The photo specimen had no obvious scales.
Cleaning: These fish will generally be factory cleaned, but with gills still in. The body cavity is rather large, so if you get an uncleaned fish expect to remove a lot of stuff. The gills are soft but large, and can be easily cut out with kitchen shears.
Fillet: This is not so easy, not only because the size of the fish makes it difficult to handle but also because it is very limp and lacks an easy to follow bone structure. The skin is also rather tough and difficult to cut through, but the flesh is so tender it must be handled with considerable care lest it come apart. I suggest removing the head and tail immediately to make it easier to handle.
When you get to the rib cage, just cut the ribs away from the backbone with kitchen shears and pull them from the fillet with long nose pliers. There are also substantial centerline spines to pull for the length of the body cavity, again with the long nose pliers.
Skin: The skin is thick, strong and easy to remove by the usual long knife and cutting board method. You should cut off the thin skirt area to make the fish narrower, then skin the skirts separately. The skin needs to be removed for any cooking method, but can be used on its own (see below).
Yield: A fish weighing 6 pounds 15 ounces factory cleaned yielded 3 pounds 11 ounces skin-off fillets (53%) plus 12 ounces of skin.
Cooking: The specimen fish was too tender to cook by any method except baking or broiling. I suggest using it for fish balls and patties.
The skin can be handled as salmon skin is in sushi bars. It is broiled moderately crisp, generally on an oiled foil in a toaster oven. It can be eaten as a snack or made up with rice and nori as salmon skin rolls are.
Stock: The head (split and gills removed), fins and bones made a very fine and usable soup stock.