This is a recipe I modified from the internet, and have found it to be particularly easy and effective. You will find the bones will usually dissolve away in the acidic pickle, and the thinner the fillet the more effective this process becomes.100 g sea salt
1250 ml water
500 g herring fillets
500 ml white vinegar or white wine vinegar
60 g white granulated sugar
1 Tbsp mustard seed
1 tsp grated allspice
2 Tbsp. black peppercorns
1 lemon, thinly sliced
1 medium red onion, sliced into individual rings.
Make sure the herring fillets are properly cleaned and the scales are removed with a spoon under flowing water.
1. Dissolve 100g salt in a litre of water and pour into a lidded container.
2. Add the herring fillets and leave for 24 hours in the fridge.
3. Add 250 ml water, the vinegar and sugar and spices and boil, simmering for ten minutes to release the flavours from the spice. Then allow this to cool.
4. To sterile jars add some herring fillets, a couple of lemon slices and a generous amount of onion. Pour the cooled pickle into the jars and then add the spices left behind from the pickle, equally distributed between the jars.
5. Seal the jars and refrigerate, where they will last up to five weeks.
Rollmops are basically the same recipe. There are millions of recipes for rollmops, some using salt and sugar, no vinegar. If this is the case it really is important to get the bones out.
Chopping gherkin, ginger and celery and adding this to the marinade. Then the herring fillets can be laid skin side down and the solid parts of the marinade spooned in the fillet, then rolled and held in position with a toothpick.