Caviar is a prized delicacy the world over and can cost as much as $200 an ounce. Generally speaking, caviar is salted roe (egg-filled ovary) of sturgeon or other large fish; usually served as an hors d’oeuvre.
In the United States, salmon or paddlefish have also been used to make caviar. And while unfertilized eggs of nearly any female fish can be separated from their egg sacks and eaten, according to the USDA, true caviar comes from sturgeon only.
Caviar made from any fish but sturgeon must contain the species identifier in its name, so a container with salmon roe must read “salmon caviar” not just “caviar.”
Caviar is a an excellent source of protein, amino acids, omega-3s, vitamin D, iron, magnesium and selenium, but caviar is high in sodium and cholesterol, and there are food-borne illness risks when consuming raw foods.
The caviar industry originated in Eurasia and the Mediterranean and can be traced to the 13th century from Batu Khan, Genghis Khan’s grandson. Eventually, the French began importing the delicacy from Russia.
Historically, the fish eggs were heavily salted to preserve the shelf life and then placed in wooden barrels.
Sturgeon have existed for roughly 250 million years; they reside in estuaries where salt and fresh waters merge, but spawn in freshwater.
The primitive fish are located in the northern hemisphere and have over 20 major species — the Acipenser family tree includes 27 sturgeon. Some sturgeon live a century or more and can reach over 4,000 pounds.
Three sturgeon species — beluga, osetra and sevruga — supply most of the world’s caviar and are found in the Caspian Sea which is bordered by five nations including Iran, Kazakhstan and Russia. Caviar is also produced from the Black Sea and Sea of Azov.
In 2008, Science Daily reported that most sturgeon species are endangered, having been overfished nearly to extinction in pursuit of their caviar. The Caspian Sea is home to beluga sturgeon, whose eggs are considered to be among the finest in the world.
Despite evidence that beluga sturgeon stocks have declined by a staggering 90 percent in the past 20 years, CITES’ (The Convention on International Trade in Endangered Species) 2008 export quotas permitted the fish and their eggs to be harvested.
The decimation of these three primary sturgeon stocks has created demand for other sources of roe, as well as private sturgeon fish farms such as Breviro Caviar and Sterling Caviar farm near Sacramento, California.
Caviar Processing Methods
In her comprehensive article, author and journalist Laurie L. Dove explains that the freshest caviar is extracted from live sturgeon who are slit open to remove the ovaries.
Harvesting eggs is a delicate process that often done manually because roe is fragile and easily damaged.
“The roe sacks, or ovaries, are opened and rubbed across mesh screens using gentle pressure from the palm of the hand — this action separates the eggs from the membrane and they drop through the screen into a shallow tub. The eggs are then rinsed with cold water and salted.”
Dove goes on to explain that after several hours, the resulting brine is drained and the roe, which is now caviar, is packed in containers with airtight lids. Fresh caviar will keep for two to four weeks.
Most modern malossol caviars contains less than 3 percent salt and is the highest quality.
Semi-preserved or salted caviar has a salt content up to 8 percent and sacrifices taste for a longer shelf life.
Pressed caviar has a high salt content (up to 10 percent salt) and is compressed into jam-like cakes that will keep for three months. It is usually made from overly ripe roe, which sometimes are damaged and too soft.
Pasteurized caviar is made from fresh caviar that is packed in glass jars for longer preservation. Taste and texture is usually compromised. It is treated in high temperature and vacuumed packed.
Although still fresh, pasteurized caviar sacrifices taste for a longer shelf life. Lesser grades of caviar with up to 10 percent salt are compressed into jam-like cakes with concentrated flavor called “payusnaya,” that will keep for three months.
Dove points out that pasteurization decreases the risks of encountering a food-borne pathogen, such as Listeria, which can be harmful to pregnant women. It also creates a shelf-stable product that can withstand a year of unrefrigerated storage and shipment.
Unlike pasteurized caviar, fresh caviar must remain at a constant, chilled temperature when shipped and has to be turned often so the fat evenly coats each egg.
Dove compares caviar varieties to grapes used in wine making, and adds that the essence of caviar is influenced by many factors as the eggs ripen.
The rare beluga sturgeon produces large caviar that is light to dark gray in color. Dove describes the taste as buttery and less intense than fine-grained caviar, and says the coarse row offers a delicate texture.
“In contrast, the eggs of the small sevruga sturgeon are blackish green with a concentrated flavor. The medium-sized osetra sturgeon produces caviar that is deeply golden to dark brown in color and features a nutty taste.”
For each type of sturgeon, Dove claims there are two grades of caviar: Grade 1 features firm, large, intact eggs, delicately taut with fine color and flavor, while grade 2 is not as aesthetically pleasing to the eye or palate.
Although beluga caviar is the most sought-after, costing about $400 for two ounces, the rarest, and therefore most expensive caviar is golden caviar.
Also known as “royal caviar” it is thought to be eggs that would produce albino osetra. This caviar, a pale daffodil color, is found in only one in 1,000 osetra sturgeon.
Russian and Iranian caviar is popular the world over, but wild-caught American Atlantic and white sturgeon is gaining demand in the global caviar trade.