SPICES IN general and pepper especially became important flavoring agents before the invention of the refrigerator, masking or improving the taste of foods that had been primitively stored.

In ancient Greece, pepper was valued on a par with gold and was regularly used as a medium of exchange. Columbus was looking for the great peppermill in the east. He may not have found it, but New England sea captains in the early 1800s dominated the pepper trade and made Elihu Yale (of the university) one of America's first millionaires.

Pepper became popular because it can be stored for many years without losing its aroma. But to keep its flavor intact, pepper must be stored with its hull unbroken and ground only just before use. Commercially ground pepper sold in cans has usually lost all flavor value before you get to use it, and the pre-ground pepper in restaurants might as well be sawdust.

Black pepper and white pepper are the same fruit from a tropical vine. Black pepper is harvested when green, left in heaps to ferment for a few days then dried in the sun until shrivelled and the outer hull turns dark brown. White pepper is produced from fully ripened red berries which have been seeped in water for a week. The softened berries are then trampled to rub off the outer the hull and left in the sun until it turns a creamy white.

For esthetic reasons white pepper is often preferred over black, a more pungent pepper, for use in light-colored foods. But no matter which color pepper you are using, it should always be purchased whole and ground as you use it. Therefore, every serious kitchen needs at least one peppermill.

The most important part of any mill is the grinding mechanism. It should be adjustable and made of stainless steel. It is essential to be able to go from fine to coarse grind. A peppermill should hold a minimum of an 1/8 of a cup of peppercorns or you will literally be refilling after each twist. The refilling mechanism should be simple and easily handled.

The best peppermill for use in the kitchen is the Perfex mill made in France. It has a cylinder of cast aluminum and a tempered-steel mechanism. A swing handle at the top gives you a secure grip even when your hands are wet or oily . . . a distinct advantage over the knob-grip peppermills.

There is a large shoot that pulls out from the center of the cylinder, and it's a simple task to open the shoot and refill the mill. The adjustable tension nut on the bottom of the mill can be loosened or tightened in order to control the coarseness of the pepper as it is milled. The Perfex comes in two sizes: 4 1/2 inches high for $25 and 3 1/2 inches high for $23.

Most food authorities agree that the finest grinding mechanism is made by Peugeot. The mechanism is available in lightwood mills, darkwood mills, stainless-steel, silver, gold and almost every other material in which one could imagine a peppermill.

The body of these peppermills is held in one hand while the knob top section is turned with the other hand. Peppercorns are fed down the hollow core into the milling system at the base. A nut at the top of the mill is turned tighter or looser in order to determine how fine the grind will be. If you completely unscrew the control nut, you will be able to remove the knob top and refill the central core of the mill.

Peugeot makes a beechwood mill in both natural and walnut-stained finishes. These are the best mills available and work well either in the kitchen or on the dining room table. Priced at $11.

There is a classic wooden coffee mill miniaturized for use with pepper. Peppercorns go in at the top, are ground through the mechanism and delivered to a small wooden base. There are four possible grinds, which are selected via a notch system at the top. Made by Grulet in France, this mill is used primarily in the kitchen when a fairly substantial quantity of pepper is needed for a recipe. Priced at $15.

There is a California maker whose mills are designed along Peugeot lines and whose name can be trusted. They are widely distributed under the Olde Thompson label. Prices range from $9 to $16.

Another California company is William Bounds, whose clear lucite mills crush rather than grind the pepper, a method preferred by some gastronomes. They have three grades of fineness and have proven dependable during the two years they've been tested. They come in various sizes and have a price range from $10 to $15.