Chocolate is rich in cocoa butter, which is polymorphic (it crystallizes in several forms as it solidifies, only one of which, the "B" form, is stable). The tempering process affects the crystalline structure of cocoa butter, inhibiting the formation of non-B crystals with lower melting points. If chocolate is melted improperly, some of these unstable crystals can rise to the surface and create a dull, streaked finish, called "bloom."

There are a number of different tempering methods, and each chocolatier will defend his as zealously as he guards his recipes. Since each product contains different amounts of cocoa butter, dark and milk products are subjected to different temperature ranges, and these can even very slightly from manufacturer to manufacturer. The accompanying chart illustrates the typical range for what is known as the "three temperature method" used widely in Europe.

Although chefs and some chocolatiers temper by hand, the process is fully mechanized in chocolate factories. Most machines feature water-jacketed thermal containers which can melt, temper, and

store chocolate. Scrapers sweep the bottom and sides of the containers every few seconds, and stirring mechanisms keep the chocolate thoroughly mixed. Some units feature pumps and tubes that enable chocolate to be pumped directly to and from other machines; e.g., coating and molding machines.

This edition of the Flyer Chocolate Letter is published and copyrighted 1990- by Paris Chocolates, Inc., P.O. Box 1281, Washington, CT 06793, Tel: (800) CANDY BAR. Flyer Candy Bars, chosen the best in New York City by New York magazine, have received rave reviews in such media as The Boston Globe, Chef, Chocolatier, Food & Wine, The New York Times, and WOR Radio, New York.