The factors that are considered in the grading of caviar are the following:
– uniformity and consistency of the grain,
– the size,
– the gleam,
– vulnerability of the roe skin.
Grade 1 is caviar which ideally combines all properties: it must be firm, large grained, delicate, intact, of fine color and flavor.
Grade 2 is also fresh caviar with normal grain size, very good color and fine flavor.
In this grade, external effect caused the fracture of more than 35 percent of the roe skins before it was removed from the fish. Therefore, this caviar is treated in a different manner than grade 1 and grade 2 caviar. It consists of a roe blend from the Osetra and Sevruga. This blended roe, usually milky and soft, is heated to 38 degrees Centigrade in a saline solution and stirred until it has absorbed salt and regains its natural color. Then, it is cast into “talees,” fabric pouches in which it is pressed out to remove excess salt and oil.
Pressed caviar contains four times more roe than fresh caviar of the same weight. It is drier, spreadable, and it is also considered to be a delicacy. Because it takes four pounds of fresh caviar to prepare one pound of pressed, the resulting black paste has a highly concentrated flavor. The strong, sharp taste is favored by some gourmets.