Excerpt: Caviar

the appetizer:

The Science of Good Food by Andrew Schloss and David Joachim explains the mysteries of food and cooking. Check out topics like Caviar; Extracts; and Sweet Potatoes; plus recipes, including Acorn Squash Filled with Pumpkin Seed Risotto and Roasted Root Vegetables.

Cookbook

Caviar

What It Is

Fish roe is available in two basic categories, hard roe (female eggs) and white or soft roe (the milt or seminal fluid of male fish). In North America, only eggs from sturgeon can be labeled simply "caviar." Other fish eggs must specify the fish from which they come, such as "salmon caviar." Traditionally, true caviar comes from wild sturgeon in the Caspian and Black seas. The three varieties include beluga, osetra, and sevruga, ranked in that order from largest size to smallest and highest quality to lowest. See Caviar Types and Characteristics chart, right, for other types of caviar.

The term malassol (Russian for "lightly salted") indicates that you're buying only 2.5 to 3.5% salt by weight and often appears on the finest caviar, taken early in the spawning season. "Pressed caviar" refers to ripe eggs taken late in the season, often damaged, and pressed together to hang and drain, which compacts them into a spreadable, jam-like consistency. It takes about 5 pounds (2.2 kg) of ripe eggs to make 1 pound (454 g) of pressed caviar, which often contains more salt than other varieties (up to 7%) yet costs about half as much. Pressed caviar is concentrated and has a stronger flavor than loose caviar.

Some fish eggs are pasteurized at 120 to 160°F (50 to 71°C) for one to two hours to improve their shelf life, which creates a slightly firmer, more rubbery texture, and greatly diminished flavor.

Caviar Types
*Caviar Types and Characteristics* Overfishing of wild sturgeon has led to caviar's dwindling availability, so eggs from other wild and farmed fish have become popular and generally referred to as "caviar." This chart describes each type of fish egg, gives its alternative names in the marketplace, and includes eggs from shellfish such as lobster and sea urchin.
Sources and Names	Characteristics
Bowfin (Cajun caviar, chou pique)	Black, shiny, small, firm; turns red when heated
Capelin (masago)	Orange, somewhat translucent, very small; often served with sushi
Carp (tarama)	Light pink, very small; occasionally salted; puréed to make Greek taramasalata spread
Cod (tarako)	Pink, very small; salted and sometimes smoked; available as a paste in tubes
Flying fish (tobiko)	Red-orange (sometimes dyed black), small, crunchy
Grey mullet (Sardinian caviar, bottarga di muggine, tarama, karasumi)	Amber, small; often salted, pressed, and dried; puréed to make Greek taramasalata spread
Herring (kazunoko)	Yellow-pink, medium-size, rubbery; often pickled and sold in a shaped mass
Lobster (coral)	Coral pink when heated; small; often added to sauces
Lumpfish	Green (often dyed red, orange, or black). small, firm; salted and bottled
Paddlefish	Light to dark steel gray or golden, medium-size; lightly salted; rich, buttery taste
Pollock (mentaiko, momijiko, tarako)	Pink to dark red, very small; may be spiced with ground dried chile pepper (mentaiko), dyed red (momijiko), or salted and grilled (tarako)
Salmon (red caviar, ikura)	Red-orange, large, translucent, juicy; lightly salted; may be smoked; known as sujiko when sold as the whole ovary
Sea urchin (uni)	Red-orange to yellow, velvety soft; often served with sushi
Shad	Small roe swaddled in two oblong, translucent membranes
Smelt	Orange, small; somewhat crunchy; sometimes served with sushi
Sturgeon, Acipenser gueldenstaedti (osetra caviar)	Gray to brown, small; strong flavor; also includes the rare and superior golden brown grains of "golden," "Imperial," or "sterlet" caviar from the albino sturgeon of this species
Sturgeon, Acipenser sinensis (Mandarin caviar)	Grayish green, large; velvety, mildly sweet
Sturgeon, Acipenser stellatus (sevruga caviar)	Gray to reddish or greenish black, very small; very strong flavor
Sturgeon, American hackleback	Black, small, buttery; sweet (Black pearl caviar)
Sturgeon, American lake	Light to dark gray, large, soft; mildly sweet
Sturgeon, Huso huso (beluga caviar)	Light to dark gray-blue, large, velvety soft; mildly sweet
Trout	Golden brown-orange or yellow, large, firm, sticky; salty
Tuna (bottarga di tonno)	Amber, small; strong flavor; often salted, pressed, and dried
Whitefish (American golden caviar)	Pale orange or iridescent gold, small, crunchy; mild flavor; often smoked

Fast Facts

In the 1800s, caviar was served like today's salted peanuts—free of chargeto stimulate thirst and beer sales in American saloons.

In recent years, the United Nations has begun to ban the export of wild-caught sturgeon caviar to help revive the species in the Caspian and Black seas. Farmed sturgeon caviar remains a viable and good-quality alternative.

What It Does

Due to its rarity, high quality caviar is expensive (upwards of $150 an ounce/28 g) and almost always served simply on its own, perhaps with soft bread and butter or thin pancakes (blini) and sour cream.

Nutritionally, fish eggs are similar to other animal eggs but are richer in fat, cholesterol, and sodium. Three tablespoons (45 mL) of caviar (the volume equivalent of one chicken egg) contains about 120 calories, 9 grams fat, 282 mg cholesterol, and 720 mg sodium. A large chicken egg contains 75 calories, 5 grams fat, 213 mg cholesterol, and 63 mg sodium. Sturgeon and salmon caviar contain the highest levels of fat and cholesterol. Like other eggs (and fish), caviar is highly perishable and best stored on ice in the coldest part of the refrigerator right up until serving time.

How It Works

Brightly colored caviar appears orange, red, or pink from carotenoid pigments, while steely gray, brown, and black caviar is colored by melanin pigments. Apart from the richness of lipids in fish eggs, the defining taste of caviar comes from salt. Caviar was originally salted, like other foods, to preserve the eggs. Salting also creates a brine that plumps the eggs with moisture, increasing their juiciness. Salt firms up the caviar's surface, too, creating the contrast of a crisp "pop" in the first bite that releases the buttery, mouth-filling interior. Salt further enhances flavor by inducing protein-digesting enzymes in the egg to increase levels of flavorful amino acids in the caviar.

One downside to salt: it can react corrosively with such metals as silver and steel, creating off flavors in the caviar. Avoid metal spoons and dishes when serving fish eggs.