There are 24 sturgeon's species in the world. Five of them live in the Caspian Sea, and only three of them produce caviar. Caviar are the salty roes of this three sturgeons, that are the 90 % of the worldwide production:

Beluga

The biggest fish of these three, and so its roes are the biggest and the most expensive ones. It is also the most uncommon.The normal weight is 40 to 300 kgs. (even though, sometimes can be bigger than 1000 kgs) and the caviar that comes from it, is the 15% of its weight. Its color is grey, beign more appreciated the lighter its grey color is. It is sold in blue cans.

Osetra

The fish is of midium size, whose color goes from the dark-brown to yellow gold. On the average, measure 1.2 meters and he weighs from 20 to 80 kilos. He has a characteristic taste, with a soft taste of walnut. The cans are yellow.

Sevruga

This is the smallest from the three, but also the most plentyful. It measures at the most 1.5 meters and weighs a bit more than 25 kilos. 
Its roes are little and gray-colored, and it is dear for his aroma. It is sold in red cans
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The Caviar of better quality of the world comes from Russia and Irán, countries bathed by water of the Caspian Sea.

The process begins when catching the roe ( a carry-all ) and to put them on a mesh and on this way to separate the roes in small pieces.
Then they get on a bowl, where the exact quantity of sea salt is added ; They put on salt to prevent the freezing of the product, since the Caviar is a very delicate product that must be allways in optimal cold conditions ( among 0 and 3 C ). Then it is classified and put in cans.

Preparation of the Caviar

The caviar comes from the roes of the female sturgeon. The sturgeon is captured  with nets and transfered when still alive to the fisch hatchery.

Once there, they are anesthetized and beaten to empty the bags, but never are killed. The way the fishmen anaesthetize the fish is giving it a hard hit in a specific part of its head.
The roes must be extracted while the fish is alive, because when they die they produce a chemical reaction that makes the caviar bitter.

When the beluga's roes are extracted from the fish to make the quality higher, the process is manual.

 How to serve the caviar

The Caviar should be serve with creme fraiche on top of a "blini" (a blini is a kind of crepe), also can be placed on top of a recently made toast and accompained of a a good Vodka or Cava; can also be eaten with  a good dry white wine.

The Caviar should be served in a special plate for caviar or in a glass bowl on top of ice to mantain it always in an optimal temperature and in this way we can appreciate better its flavor. We should use nacreous scoops; never use silver tablespoons, because this metal affects the flavor of this product. In order to enrich the flavor of current caviar, we recommend to add some lemon juice drops. The estimated portion per person is about 5 to 7 spoons of caviar.