In the past, the fish was buried in the sand for a few days to preserve it. Today, it is a lot easier thanks to refrigerators.
As is often the case, new dishes come about through chance as well as necessity. Otherwise, who would come up with the idea of burying a freshly caught, cleaned and salted fish in the ground or sand for a few days? This process was developed in Scandinavia hundreds of years ago and became known as "buried salmon" (Swedish "gravad lax" and Norwegian "gravlaks"). The term we use "graved lax" originated from that. Water is extracted from the salmon by the physical pressure of the soil or sand and the salt-sugar pickling solution. Drying and fermentation take place simultaneously, preserving the fish for longer. For this reason, it is important to store the spiced fish as airtight as possible with cling film or in a large freezer bag and weigh it down with tins, for example, in the refrigerator.
In principle, salt and sugar suffice for the preservation process. The herbs are only used for flavouring. In addition to traditional herbs such as dill, chervil and parsley, you can use lemon balm, bay leaves, coriander and marjoram. Spices made with coarsely ground peppercorns can also be varied very easily with mustard seeds, allspice, juniper berries, cardamom, coriander or fennel seeds. Rubbing olive oil on the salmon after pickling and after removing the spices and herbs will prevent it drying out.