This is my favorite recipe for pickling mackerel. I've been using this classic option for many years. You can eat mackerel already on the second day; it turns out slightly salted; on the third or fourth day it becomes more tart.
Prepare the fish: defrost if necessary, remove the head and entrails.
Pour 0.6 liters of water into the pan, add salt, sugar, pepper and bay leaf. Place on the fire, bring to a boil and turn off after a minute. Cool the brine.
Pour the prepared mackerel with the resulting brine and place it in the refrigerator for 2 days.