The term soused herring usually refers to a cooked herring in a mild vinegar marinade. The herring can be baked in the marinade or fried and then soaked in it. It is served cold. As well as vinegar, the marinade might contain cider, wine or tea, sugar, herbs (usually bay leaf), spices (usually mace), chopped onion.

The word 'soused' usually means 'soaked in a mild preserving liquid', and can be used to refer to raw herring in a mild vinegar pickle or the famous Dutch brined herring.

The Dutch soused herring (maatjesharing in Dutch, or matjes in (German and Swedish) is an especially mild salt herring, which is ripened using the enzymes in a salty solution, or brine. In Britain and Canada these are sometimes marketed as 'roll mop herring'.

History

This process of preparing herring (known as "gibbing") was developed in the Middle Ages by the Dutch. Herrings are caught between the end of May and the beginning of July in the North Sea near Denmark or Norway, before the breeding season starts. This is because herrings at this time are unusually rich in oils (over 15%) and their roe and milt have not started to develop.

The brine used for Dutch soused herring has a much lower salt content and is much milder in taste than the German Loggermatjes. To protect against threadworms (nematodes), Dutch regulations mandate freezing to at least minus 45°C before salting. In the modern day, soused herrings can therefore be produced throughout the year.

Preparation

Through a cut in the throat, the gills and part of the gullet are removed from the herring, eliminating any bitter taste. The liver and pancreas are left in the fish during the salt-curing process because they release enzymes essential for flavor. This process is called: gibbing. The herrings are then placed in the brine for approximately 5 days, traditionally in oak casks. They require no further preparation after fillet and skin removal and can be eaten as a between meal snack with a few finely cut raw onion rings.

As skin removal demands experience, fillets or double fillets should be attempted first. The soused herrings are silvery outside and pink inside when fresh, and should not be bought if they look grey and oily.

Whereas salt herrings have a salt content of 20% and have to be soaked in water before consumption, soused herrings do not have to be soaked.

Serving

Soused herring dishes in Northern Germany are traditionally served with potatoes boiled in their skins, French beans, finely sliced fried bacon and onions. It is also common in Germany to eat soused herring with sliced raw onions in bread, in a dish called matjesbrötchen.

Soused herring can also be served with cream or yoghurt sauces, or in salads.