he 53-year-old co-owner of Green River Chocolates is busy preparing custom-molded confections for the holidays as customers buzz about Trillium Cafe in Hinesburg. Fresh-baked bread is served with frittatas and hot chocolate in this sunny shop, which Sirotkin and his partner Beth Sengle opened earlier this year in the Commerce Street building that once housed the post office. The venue provides a physical outlet for the retailer's 4-year-old Internet bulk-chocolate business (grchocolates.com).

Sirotkin began selling chocolate wholesale in 1988. Now, Green River sells retail treats such as chocolate bark with coconut, chocolate cakes and chocolate-covered coffee beans, but it also offers something more unusual to the average chocoholic: bulk bars. Why?

"So people get the most chocolate for the money," explains Sirotkin. "For people who want chocolate, they don't need to pay for all the frills of boxing and wrapping when all you want is the chocolate."

A standard 1-ounce candy bar such as Mounds will set you back a buck, and the chocolate isn't anything to write home about. At Green River Chocolates, you can invest in an 11-pound brick of, say, "Windsor," a dark chocolate with 68 percent cocoa content, for $53.

"Windsor" is produced by the obscure German chocolatier Schokinag. It's one of 26 chocolates -- white, milk and dark, fair trade and organic -- from seven producers Sirotkin sells. Domestic Merckens and Guittard are from the East and West Coast, respectively, while Peters, also from the U.S., was developed by Nestle. Belgian Callebaut is the brand that goes into Lake Champlain Chocolates. Green and Black's, from England, is organic and fair trade. At $85 a pound, it's a pricier choice. But it's not as high-end as French Valrhona, which fetches $85 a kilo.

"Chocolate is like wine," Sirotkin suggests. "You find one or many that you like. It's not that one is better than another... You don't drink the same wine every night, you skip around." His own taste runs to dark chocolate. His current favorite is Schokinag's high-octane "Bristol" -- with 75 percent cocoa content, it packs the biggest cocoa wallop the company offers.

Green River customer Diane Snelling, a State Senator from Hinesburg, agrees with Sirotkin. Schokinag's "Bristol" dark "was something like I had never tasted," she says. "I tried other chocolates to compare, but kept coming back."

Chocolate lovers, home bakers and kitchen chocolatiers buy Green River's chocolate for making confections, baking and eating. Although you can buy roughly a pound of bulk Callebaut or Valrhona chocolate at Lake Champlain Chocolates' factory store, some chocophiles seek a greater variety for their palate.

"What Green River Chocolates is making available is unusual," says Clay Gordon, founder of chocophile.com, a website offering information, chocolates and message boards for choco-fans. "It's very difficult for a retailer, even a specialized retailer, to sell large quantities of chocolate retail unless they're using it themselves or they have a good Internet business. That makes him extremely unusual," says Gordon.

Bulk chocolate for baking or making confections is sold in a few places online and in even fewer bricks-and-mortar retailers. Thus Green River is "providing a valuable service to people around them who want to have access to this stuff," Gordon notes.

Lots of people do, judging from the number of websites and online user groups devoted to the food of the gods and the search for cocoa contents as high as 99 percent. "There is a large group of people looking for this," confirms Gordon, who just last spring founded the New World Chocolate Society, a 3000-member association dedicated to all things chocolate. He says that a lot of people write to him asking how to find specific brands. "To some extent people are stymied -- they're not sure how to find what they are looking for."

To help chocolate lovers make up their own minds, Green River offers "The Chocolate Party," with samples of as many as 20 different varieties -- from white chocolate with high sugar content and low cocoa levels, to dark chocolate with low sugars and up to 75 percent cocoa content. The kit is designed for the chocolate equivalent of a wine tasting. Consumers can take notes on brands and cocoa contents to hone in on their personal chocolate preferences.

And, as with wine, there's a particular technique to tasting chocolate. "The old joke with the M&Ms slogan, 'It melts in your mouth, not in your hand' -- that's the antithesis of what chocolate is about," says Sirotkin. "Good chocolate should melt at body temperature." The flavors of a chocolate come out when it sits on your tongue and begins to melt, he explains.

Peter Gillette, a longtime Green River Chocolates customer and friend of Sirotkin, has the tasting technique down. He sometimes helps Sirotkin out by doing blind taste tests, sampling several chocolates and describing the differences between them. "It's interesting to taste what differences there are within a class of milk chocolates or dark chocolates," he says.

Within each category of Green River's chocolate lineup, favorites have emerged. Customers who crave white chocolate flock to "Lincoln," a creamy Schokinag chocolate with pure cocoa butter. Milk-chocolate lovers prefer Schokinag's "Cambridge" or "Richmond," or the creamy Merckens. Topping the dark-chocolate list are Schokinag's "Windsor," distinguished by its intense, bittersweet flavor, and Merckens' "Bordeaux," which has wide appeal and a fruity flavor. Just making it through those favorites could take you a week.

"That's the fun part about coming here," says Sirotkin. "You can come every day for a month and taste a different chocolate."