Beluga caviar (the roe of beluga sturgeon) is one of the most prized caviar varieties in the world. Since it can take up to 25 years for the animal to mature and start producing roe, this caviar is extremely rare, expensive, and extravagant. Beluga caviar beads are large, plump, and firm, with a color that can range from light to dark gray.

With a delicate, tender, and almost buttery flavor, beluga caviar can be eaten plain, allowing the complex layers to develop individually. It is also commonly combined with boiled potatoes, blini pancakes, or sour cream. Recently, wild beluga varieties have become critically endangered, partially due to wild poaching in the Caspian Sea, and strong sanctions have been introduced to limit the production, sales, and trade of this rare ingredient.

Osetra is a prized caviar variety that is harvested from the Russian osetra sturgeon (Acipenser gueldenstaedtii). Osetra is native to the Caspian Sea, the Black Sea, and the Sea of Azov, including their river basins. Since it is a critically endangered species, it is rarely found or caught wild, and caviar is mostly harvested from farmed varieties.

Osetra has medium-sized eggs that often vary in color, flavor, and texture. They typically range from olive green to dark brown, sometimes with an appealing golden hue. Their texture is firm, while the flavor is usually briny, buttery, and distinctively nutty. 

Siberian sturgeon is mostly prized for its dark and glossy caviar. As the name suggests, Siberian sturgeon (Acipenser baerii) is mainly associated with Siberian rivers, lakes, and seas. The population is listed as endangered on the IUCN Red List, and caviar is mostly harvested from farm-raised sturgeons.

This caviar ranges from dark brown to black, and it typically has medium-sized, glistening beads. The flavor is earthy, nutty, buttery, and subtly sweet. It can be served on its own—preferably well-chilled—or paired with simple dishes such as the classic combination of blini pancakes and crème fraiche. 

Salted roe of the sevruga sturgeon is one of the most common and renowned caviar varieties in the world. Native to the Black and Caspian Sea, sevruga reproduces faster than other sturgeon varieties, which makes the caviar plentiful and more affordable.

Although small in size, the crunchy caviar beads are packed with salty, buttery flavors and usually range from light gray to black. Although it is said that this specialty is best enjoyed plain, eaten exclusively with a pearl or wooden spoon and paired with Champagne, sparkling wines, or vodka, it is also commonly combined with blini pancakes, potatoes, or bread.

White sturgeon caviar is harvested from Acipenser transmontanus—a sturgeon that is native to the west coast of North America, from the Gulf of Alaska to Baja California. Often compared to osetra, this caviar has glistening dark pearls, ranging from dark brown to black.

The beads are usually medium-sized and firm, while the flavor is clean, crisp, nutty, and buttery. White sturgeon is considered one of the most environmentally friendly caviar options, but the production and the sales are strictly regulated. This caviar is excellent served on its own, but it also pairs well with blinis, crème fraîche, seafood, and creamy sauces. 

Almas, which translates as diamond, is the most expensive caviar in the world. It is harvested from an albino beluga sturgeon (Huso huso), which should be between sixty and one hundred years old, and which is only found in the southern Caspian Sea—presumably because the area is less polluted.

Almas caviar has a distinctive light yellow color, plump and delicate orbs, while its flavor is briny, creamy, and buttery. Because it is incredibly scarce, this caviar reaches astronomical prices—on average £20,000 ($30,800) per kilo—and it is traditionally sold in 24K gold tins. 

Sterlet caviar is a variety harvested from sterlet sturgeon (Acipenser ruthenus)—which is native to rivers that flow into the Caspian Sea, Black Sea, Baltic Sea, Barents Sea, and the Sea of Azov. It is one of the smallest sturgeons, and it matures faster than other sturgeon varieties, which makes it especially suitable for farming.

On the IUCN list, starlet sturgeon is listed as vulnerable, and the fish is now mostly farm-raised. Sterlet roe has small and delicate eggs that range from light to dark gray. The flavor is mild, subtly sweet, and buttery. This caviar is best paired with buttered toast, blini, potatoes, or eggs. 

Hackleback caviar is harvested from Scaphirhynchus platorynchus, known as shovelnose or hackleback sturgeon. The fish is native to North America, and it is mostly found in Missouri and Mississippi rivers. It is the smallest sturgeon species in North America, and the only one that is still sometimes commercially caught in the United States.

The species is listed as vulnerable. Hackleback caviar usually has small, glistening beads that range from dark gray to black. The flavor is sweet and buttery, with a distinctive nutty aftertaste. Because the fish matures earlier and is still available in the wild, hackleback caviar is usually not as expensive as other sturgeon caviars. 

Caviar from Brescia is one of the most popular regional products, and the entire region has become the center of caviar production in Italy. Sturgeon farming started with white sturgeon (Acipenser transmontanus), but other species and caviars are now farmed and produced.

White sturgeon caviar (Calvisius) is round, large, smooth, and tender, while the flavor is intense and complex, dominated by fruity, briny, and nutty notes. The tradition of farming sturgeons was started in Calvisano by the Tolettini family. They used the water for steel mills and directed it into large fish tanks.