Pin bones are those tiny bones that end up in some fish fillets, and provide a not-too-pleasant surprise when one is trying to chew a tender mouthful of salmon.
Like mammals, fish have a flexible backbone (spine): a series of interlocked disks (vertebrae).
When a fish is cut into fillets, the backbone is removed, as are any larger bones running along the vertebrae.
The fillet is then considered to be “boneless.”
However, some fish have smaller intramuscular bones that can go unnoticed.
Fish in the salmon family have what are called pin bones.
They are actually calcified nerve endings that extend along the lateral line of the salmon.
Pin bones are impossible to remove through filleting, says Sitka Salmon Shares, from whom we get a monthly delivery of filleted Alaskan fish.
They tell us that large Alaskan processors remove them with a pin-bone machine (photo #2). However, to sell the freshest fish, Sitka Salmon Shares doesn’t do so*.
In order to use the tool, the salmon have to “rest” for a few days to soften the flesh.
However, this means the fish is not sold at its freshest; so the finest salmon (and some other varieties) may have a few bones.
They’re easy enough to remove with a kitchen tweezers*.
Soft enough to eat, pin bones are actually considered a delicacy in Japan, according Leite’s Culinaria.
But we wager that most people prefer to remove them. So follow these instructions:
 Chart © Sitka Salmon Shares.
*While some chefs use specially-designed tweezers, you can use any pointed-end tweezers that are dedicated to kitchen use.