But many of the smaller chocolate makers see the effort to replace cocoa butter as a ploy that would allow the major companies to cut costs without risking their reputation—or sales. And that, the smaller companies argue, would not only mislead consumers but also give mass chocolate makers an unfair advantage.  

The potential savings are substantial. By substituting other vegetable fats, chocolate makers could shave at least 50 cents a pound off the cost of producing their candy, estimates Fabrizio Parini, vice president of marketing for Ghirardelli Chocolate, which opposes the change.

Furthermore, premium-chocolate makers fret that the change could spark a consumer revolt against all chocolate. “It would be like saying margarine spreads could be called butter,” says Brad Kinstler, See’s chief executive, who’s decked out in a white lab coat and matching hairnet as he gives me a tour of his South San Francisco plant. A glimpse at the production line helps explain why See’s charges a premium for its candies: Workers are painstakingly painting chocolate onto caramel-almond chews that are moving along a conveyor belt toward a cooling tunnel.

The cocoa-butter controversy began in October 2006 at a Washington board meeting of the Chocolate Manufacturers Association, a trade group dominated by the biggest names in chocolate: Hershey, Nestlé, Mars, and Archer Daniels Midland. The board was considering whether to support the Grocery Manufacturers Association, which includes some chocolate makers, in petitioning the F.D.A. to update U.S. food standards. The grocery manufacturers group, which happens to be chaired by former Hershey C.E.O. Richard Lenny, routinely submits such petitions when changes in food science demand it. But deep within the fine print of the document—in the last section of a 12-page appendix—lurked the clause allowing the cocoa-butter substitution. Most small chocolate makers were absent from the meeting, and there was no vote on the petition.

Gary Guittard, a member of the Chocolate Manufacturers Association and the owner of Guittard Chocolate, a boutique chocolate company started in 1868 by his great-grandfather in Burlingame, California, had been digging into the petition’s fine print when the phone rang. It was a Chocolate Manufacturers Association representative, who was polling members on the proposed F.D.A. standards. Guittard voiced objections to the cocoa-butter clause, but a few weeks later, the chocolate trade group announced its support for the petition—including the cocoa-butter swap.

“The phone vote was weird,” the 60-year-old Guittard recalls, speaking from his desk in the same brown office his chocolate-making predecessors occupied in the 19th century. Guittard swung into action, conducting his own informal poll of premium-chocolate makers and their allies, alerting them to what he saw as a threat. Soon they banded together and created a website, DontMessWithOurChocolate.com. They denounced the proposed change as a “mockolate conspiracy” and bombarded the F.D.A. with protest letters and emails. As a result, the F.D.A. extended the public comment period and said it wouldn’t be deciding anytime soon.

Major industry players don’t want to talk about this, though Mars broke ranks with other big makers and recently came out against the change. Archer Daniels Midland and Nestlé would not comment specifically on the debate, and a Hershey spokesperson deflected comment to the Grocery Manufacturers Association.

Meanwhile, the fracas has created strange bedfellows. With the growth in premium-chocolate sales, some big chocolate makers have been trying to cash in by investing in boutique candymakers. Hershey, for example, recently spent $46.6 million to buy premium chocolatier Scharffen Berger. When I spoke to Ray Major, master chocolate maker at Scharffen Berger, he said adamantly, “We won’t be changing our chocolate.” He then invited me to come by Scharffen Berger’s factory in Berkeley, California—subject to approval from his new parent company.

Ten minutes later, Hershey’s press office called to rescind the invitation.