July 18 is National Caviar Day, making this a good time to learn the basics of fine fish roes. The drama and culinary delight of caviar --known as black gold for its rarity and price point --bring an Old World elegance to any meal. Here is all you need to know to bring caviar into your home, whether your budget is copper or gold. To carry the name, Champagne must come from a specific region of France. To earn its name, caviar must come from one of three sturgeon breeds (there are 27 worldwide) from the Caspian Sea. There are great sparkling wines that are not "Champagne," and there are great fish roes that are not "caviar," but provide an enjoyable facsimile. Roe is the mass of eggs contained in the ovaries of a female fish or shellfish. Sturgeon caviars share certain flavor characteristics across the breeds (varietals); a taste of the sea similar to the juice of a perfectly fresh oyster, a taste of brine, and occasionally a metallic finish. Varietal flavors differ fish by fish and tin by tin. Each fish's diet, environment, maturity and time of harvest affect the flavor and texture of the eggs. How quickly the eggs are processed, how much salt is used, and how they are cured affect the product. Iranians, for example, use brine, while Russians stir salt in directly. Properly prepared caviar should have "enough salt so the casing can be felt on (your) tongue but with a gentle press will burst and flood your mouth with the flavor of the sea," says restaurateur Nick Peyton. True Caviars are imported, and can be wild or farmed. They are named for their Sturgeon: