Although fried Baltic herring fillets are best eaten freshly fried in butter, in case you will have any left over, here is a traditional Nordic way to store and serve them.

The slightly warm or cold herring fillets are left to marinate overnight in a sweet-and-sour vinegar brine. The marinated fillets may then be eaten cold with various additives or served on open sandwiches.

Increase or decrease the amount of marinade according to the quantity of fried herring fillets. Those wanting a subtler flavour may replace the spirit vinegar with regular white wine vinegar.

previously prepared fried Baltic herring fillets  —  cold or lukewarm

100 ml water
50 ml sugar
50 ml spirit vinegar (10 %), or regular white wine vinegar
about 10 whole allspice berries
1 - 2 bay leaves

thinly sliced red onion (or regular onion)
(chopped, fresh dill)

There are several different methods to prepare this dish. The marinade may simply be mixed in a bowl until the sugar has dissolved and poured over cold herring fillets, or it can be boiled for a couple of minutes and poured warm over warm fillets, or cooled down after boiling and poured over cold fillets. In this recipe, the last mentioned method is used.

Place the water, vinegar, sugar, allspice and bay leaves in a small saucepan. Bring the mixture to the boil, slightly lower the heat and let the mixture boil for a few minutes. Pour the marinade in another dish to cool down to about room temperature.

Place the fried, cold herring fillets in a shallow glass or ceramic pan or bowl, slightly layering them if necessary (see the picture on right).

Spread some onion slices (and chopped dill, if using any) evenly on top of the fillets (and between the layers).

Pour enough cool marinade over the fillets to almost cover them. Cover the dish and place in refrigerator overnight. The fillets will be ready to eat on the next day and they will keep in the marinade for a couple of days, stored refrigerated.

Serving suggestion:
Marinated fried Baltic herring fillets are very versatile  —  they can be eaten plain as a snack, or as a part of assorted fish platter (eg on smörgåsbord), or served for lunch or dinner with boiled or mashed potatoes or other vegetables, fresh or marinated salads or any other additives one may like... However, the usual way is to serve them on top of slices of good Nordic, buttered dark rye bread.

Recipe source: adapted from traditional Finnish and Swedish recipes.