
Anyway, make sure when you get the jared version, that the herrings have been cured (raw-salted OR raw salted with sugar and spices (bay leaf, sandal wood, cardimon, cloves and pepper) as a basic preparation and NOT boiled in acetic acid which is how most (but not all) of the jared stuff is made.
Cured in the old fashioned way, means a little more salty, but also a much more savoury flavor, more bite, and more taste of the actual fish, in stead of a sweet'n sour sauce gone slightly fishy!
The proces of making pickled herrings is a long one. The first step (the curing) is essential to the finished result, and takes a minimum of three months. I assume from what little I know of herring biology, that you can't get fresh raw herrings anywhere in the US. But if you find the right shops, you might be able to get salt cured herrings (often an Icelandic product), which would make things a lot easier.