When Neal Gottlieb returned from the Peace Corps, he decided that he would follow the grand tradition of making good while doing good.

He wanted to launch “the most Earth-friendly business I could think of.”

He spent a year researching how to do it. During this time he was living with his twin brother in San Rafael, who had coincidentally married a twin; Three Twins, an organic ice cream business, was founded in August 2005.

Three Twins ice cream is garnering attention — and rave reviews — around the Bay Area. The Internet is buzzing with blog commentary about it. Metallica’s lead singer James Hetfield is among the regular visitors to the San Rafael shop. The ice cream is also sold at farmers markets and restaurants. Soon, Napans won’t have to travel far to find it. Gottlieb will be setting up shop in the new Oxbow Public Market, which is on track to open this fall.

If you want a taste even sooner, Gottlieb will be at the Earth Day celebration at Napa Valley College Saturday with samples. The event takes place from 11 a.m. to 4 p.m. on the college soccer fields.

What’s so great about this ice cream?

First of all it’s scrumptious. This writer can personally attest to this, having spent a morning tasting it. (“Ah, now this is work,” sighed one co-taster happily.) Gottlieb uses premium organic ingredients both for basic flavors, like Madagascar Vanilla or Bittersweet Chocolate, and then adds in a dash of inventiveness — and care — for other varieties, which can change depending on the creator’s inspiration. For example, the Mint Chocolate has slivers of chocolate, compared to the hard-as-rocks chunks one often finds in other versions. My son, assisting at the task of tasting the ice cream, ate the entire pint of this flavor. Likewise, Gottlieb’s Milk and Cookies ice cream is not going to break anyone’s tooth, even if one does also eat an entire pint. My son also polished off this pint, and then asked me, “When is he opening his store in Napa?”

“We’re certified organic in more ice cream flavors than any other (business ) in the world,” Gottlieb explained. “Using pure milk, cream, eggs and sugar isn’t the cheapest option, but it’s the best.”

In addition to being really good, Gottlieb’s ice cream is as Earth-friendly as he can make it. “Everything we give the customer can be composted,” he explained, at the tasting. The little white cups are made from pressed sugar cane, which is otherwise burned. Want a milkshake? That clear plastic cup is made from potato and cornstarch. So are the ice cream spoons, which are a big hit with customers.

The spoons, Gottlieb noted, cost 4 cents each, compared to 1 cent for regular plastic, but in addition to being compostible, he said, “they’re also a great marketing tool.”

“These kids came in with their mom to get some ice cream and they said, ‘Can we see the spoons?’” It turned out their dad is the aforementioned Hetfield from Metallica and he’d told them about the amazing Spudware spoons. “It was kind of something,” Gottlieb said, “to think that Mr. Heavy Metal was telling his kids about my spoons. This is what he talks about at home. Well, no one looks tough eating ice cream.”

Gottlieb said he’s following the lead of Yvon Chouinard, the mountaineer who pioneered an Earth-friendly business when he founded Patagonia, which sells top quality outdoor goods. Patagonia was the first major retail company to make fleece from recycled soda bottles, and the first to pledge one percent of its annual sales to grassroots environmental organizations. Gottlieb also makes the one percent donation to environmental groups.

“I like to think that each little ice cream cone helps preserve farmland,” he said. “It’s nothing that anyone else can’t do.”

Gottlieb, who graduated from Cornell, said he originally “wanted to write the next great American novel, but I’ll settle for the great American ice cream.”

The Three Twins shop in San Rafael is at 641 Del Ganado Road, tele. (415) 492-TWIN.