NEW BRITAIN, Conn. — A yellow Fiat 500 with the vanity license plate Peel L is more than just a promotional tool for liqueur-maker Peel — it's a metaphor.

NEW BRITAIN, Conn. — A yellow Fiat 500 with the vanity license plate Peel L is more than just a promotional tool for liqueur-maker Peel — it's a metaphor.

The adorable Italian subcompact, now manufactured in Mexico by Chrysler, has more than doubled its U.S. sales since it was introduced in 2011.

"I envision us as similar to the Fiat company," said Peel co-founder Gianfranco DiDomenico, 32, the owner of that yellow Fiat. He called the car "an old-school, old-world product they reinvigorated."

Fiat had a bad rap for a long time, he said. (People joked FIAT stood for "Fix It Again, Tony.")

And so has limoncello. As Spirits Review's Chris Carlsson wrote, as he reviewed a competing brand: "Most of the limoncello I have tried in the past was not fit for using as windshield-wiper fluid in my car. The best ones could have maybe been used as cleaners. This may be due in part to the fact that most seem to source their extracts from the same chemical factories as air deodorizers or soap companies."

Peel uses no dyes or preservatives in its three products: limoncello; crema di limoncello, called cremoncello; and bananacello, a creamy banana liqueur.

DiDomenico and friend and co-founder Angelo Mastrodomenico, 37, an immigrant from Italy, made limoncello at home for friends before introducing a commercial version of the lemon-infused after-dinner cordial in 2011. The recipe comes from Mastrodomenico's mother in Italy.

Homemade limoncello is traditionally firewater, DiDomenico said. He said Peel's recipe is smoother on the palate. The liqueur is made with grain alcohol cut with water, with lemon zest and sugar.

But having a good recipe is not the biggest challenge in starting a liquor manufacturing company, the men found.

There's a long process of getting government permission to sell each new product. They have to figure out shelf life as they develop the recipes and source ingredients. And then there's the liquor distribution system.

DiDomenico said they'd thought the liqueur should retail for $25, but distributors said limoncello should have a suggested price of $17.99 because people expect domestics to be cheaper than imports.

Peel sells to the distributor wholesale; that company marks it up and sells it to package stores. Then the package store can follow the recommendation or sell it at $19.00, $21.99, even $25.99.

"They're making all the profits," DiDomenico said, and at the highest prices, may be hurting sales. "All these things were shockers."

In the first 12 months on the market, from April 2011 to April 2012, Peel sold 12,000 bottles. It then pulled the two creams from production because locally sourced creams were eventually separating. The liqueur still was good to drink, but it didn't meet appearance standards. Now they're buying a cream used by Bailey's, and a new run of 1,000 bottles of bananacello will be back in stores in August.

Peel entered its bananacello in the San Francisco Spirits competition, and it received a double gold medal, which only seven liqueurs achieved out of a field of 167.

As they tinkered with the formulation, the founders also have decided to go with banana flavoring rather than fresh banana slices because it's difficult to time bananas' ripeness with the time slot they have at the contract distiller in Ashford, Conn.

"We've got to make sure we're consistent," DiDomenico said, and with the flavor, they can also produce more volume.

Both men have day jobs — DiDomenico owns a mortgage brokerage in New Britain, Conn., and Mastrodomenico is an aerospace engineer — but with the help of $300,000 combined subsidized loan and a grant from the state's Small Business Express program, there are two sales reps and a marketing professional on the payroll now. They work out of DiDomenico's space.

They hired two cousins to sell the liqueur. So far, there are 250 accounts in Connecticut and Rhode Island, with 100 of those in Hartford County. Next year, they plan to push for more outlets in Fairfield County and to sell into Massachusetts and New York.

About 75 percent of the bottles are sold to package stores, a quarter to restaurants.

Peel is promoting the spirits as cocktail mixers and sees its market as far broader than Italian-American limoncello aficionados. While limoncello has been the biggest seller, the cream-based liqueurs are higher-margin and, they believe, have more crossover appeal. Eventually, they'd like to introduce a strawberry- or orange-flavored cream liqueur.

They expect their gross sales this year to be in the $150,000 to $200,000 range and are shooting for 15-percent growth a year.

They take no payment for the hours they put into the business, and none of the five investors are getting a return yet, either. They estimate they'd need to sell 80,000 to 100,000 bottles a year before they could pay themselves.

"We just want to see it succeed," DiDomenico said. "Rome wasn't built overnight."