Cooking mackerel by cold smoking
I have tried this method of preparing mackerel more than once. And believe me, it’s no worse than in the supermarket. There is even a plus - it is much fresher.

Preparing mackerel.
We take three medium-sized mackerel.

If it is frozen, then you need to defrost it. Then we cut off the heads, tails and fins. We cut open the belly and remove all the entrails. Wash well and set aside for now.
Preparation of brine.

Pour 1-2 liters of water into the pan and bring to a boil. Then we take the onion skins from about 3 onions and put them in water.

Close the lid and simmer for about another 25 - 30 minutes on reduced heat. Then remove from heat and let cool completely. When the water has cooled, filter it. We won't need the husk anymore. We continue preparing the brine. Add 1-2 tablespoons of sugar, 3-4 tablespoons of coarse table salt and 1 tablespoon of liquid smoke to the strained water. There is no need to pour more, one is enough. Now mix everything thoroughly.
Cooking mackerel.
We need a container that has a lid.Place the fish there and fill it with brine.

Now you need to put it in the refrigerator for a day. If you make fish in winter, you can leave it on the balcony. After 24 hours, we take out the fish and turn it over onto another barrel. Then put it in the refrigerator for another day. Then we proceed to the final stage of preparation. Remove the fish from the refrigerator. Using an awl, we make a hole in the carcass about 2 centimeters from the tail. This is necessary in order to insert a hook there and hang it on the balcony.

It should dry for 1 day and preferably in the shade. And finally, we only need to grease it with sunflower oil. That's all.

Bon appetit.