Soaking helps to reveal the richness of the herring's taste.
Soaking this fish in milk is quite popular. The combination is strange, but it works if you don't need a very salty snack.
But herring can be soaked not only in milk. There are a whole range of other available options.

Mineral water
Some chefs recommend using carbonated mineral water with lemon slices added.
The fish turns out softer, and the taste becomes more delicate and pleasant.
Kefir
The closest alternative to milk. But in this case, the herring additionally acquires a sourish taste.
Tea
A proven method in case the herring is loose. Soaking in strong tea will give the fish density.
Wine
Only red wine is suitable for this purpose. But first you need to boil the wine with sugar, vinegar and spices for 5 minutes.
Also, the herring should first be soaked in mineral water and then cut.
After that, pour in wine marinade, add onion and put in the refrigerator. The fish acquires an unusual and exquisite taste and aroma.