My understanding comes entirely from wikipedia which states the following.
The process of gibbing was invented by Willem Beukelszoon[1] (aka Willem Beuckelsz, William Buckels or William Buckelsson), a 14th-century Zealand Fisherman. The invention of this fish preservation technique led to the Dutch becoming a seafaring power.[2]
Sometime between 1380 and 1386,[3] William Buckels of Biervliet in Zeeland discovered that "salt fish will keep, and that fish that can be kept can be packed and can be exported".
Buckels' invention of gibbing created an export industry for salt herring that was monopolized by the Dutch. They began to build ships and eventually moved from trading in herring to colonizing and the Dutch Empire.>
Gibbing sounds like a fairly simple technique to me. Is it not?
Did the Dutch keep it secret?
Or was a simple head start in perfecting the production technique enough to establish them as a monopoly?
/u/red_bob
Indeed yes, that Wikipedia article over-simplies the situation, and to be honest I have never heard of Willem Beukelszoon. There were several factors that led to Dutch dominance in the herring industry of the region.
The massive shift of herring migration, away from the Baltic sea and into the North Sea in the 14th century. This meant Dutch fishing fleets no longer had to pay the Danish sound toll to access the Baltic sea, rather they can now operate in the North Sea.
The policy of Mary of Hungary, regent of the Low Countries under the rule of Charles V, led to effective control of the fisheries against adversaries such as the French, the Scandinavians, the English and the Scots.
Dutch merchant shipping grew to include the vital link to Spain and Portugal, who were friendly to the Nederlanders, from where salt could be obtained in good quantity and quality. Over time, the Dutch monopolized triangle trade around the north sea: the purchase of grain from the Baltics, wine and salt from Iberia, and herring from their home base.
So you are absolutely right: gibbing is damn simple. But doing it in an industrial scale is what the Nederlanders were able to dominate.
Want to know more? Tracy's Herring Wars: The Habsburg Netherlands and the Struggle for Control of the North Sea, Sixteenth Century Journal, 1993, is a great paper. Or, Tracy's Holland under Habsburg Rule, a fantastic book on the formation of policy with regards to armed convoys of herring buses.