Key Lime Pie — from Aunt Sally and the spongers to Fern Butters

Citrus aurantiifolia is more commonly known as the Key lime in North America. The fruit tree is native to Southeast Asia and thought to have been brought to the New World by Christopher Columbus.

Columbus reportedly introduced the tree to Hispanola, known as Haiti today. The conquistadors who followed are credited with bringing the Key lime tree to the Americas and Henry Perrine, who worked as the U.S. Consul at Campeche, Yucatan, considered the man who introduced the Key lime to Florida.

While stationed in Campeche, Perrine received a letter from Secretary of the Treasury Richard Russ stating that President John Quincy Adams wanted all foreign consuls to identify and document potentially beneficial plants for possible cultivation in the United States. Perrine not only made copious notes, but in the 1830s sent hundreds of saplings and seeds to Captain John Dubose at the Cape Florida Lighthouse on Key Biscayne and Indian Key’s Charles Howe. Citrus aurantiifolia was among them.

Unlike the more traditional Persian lime, the smaller Key lime starts out green but, as it ripens, turns a lemony color. While its freshly squeezed juice is the absolute perfect accompaniment to a glass of rum or filet of fish, it can never be separated from its most famous incarnation, Key lime pie. The origin of the quintessential Florida Keys dessert, however, is about as murky as the mix of its essential ingredients: Key lime juice, condensed milk, and egg.

The tartly sweet dessert post-dates the creation of Gail Borden’s 1856 patent on condensed milk. When condensed, raw milk is boiled, mixed with sugar, and canned to create a viable milk product with a lengthy shelf life. The culinary genius who first mixed the product with egg and lime juice will, seemingly, forever be a mystery.

One Key lime pie origin story is credited to Key West’s as-of-yet-identified Aunt Sally.

Rumored to be a cook working for Florida’s first millionaire, William Curry, the colorful story lacks credible details such as Aunt Sally’s last name. The dessert is actually thought to have been developed by a specialized group of fishermen known as spongers. Working out on the water for days on end, sponging crews kept cans of condensed milk on board to sweeten their coffee.

The story goes that when the spongers needed to soften their stale Cuban bread, they would soak it in the milk cans. Eggs would also be cracked open and added. Lastly, lime juice was poured over the mixture and the end result became a tasty treat that could be savored out at sea, gulf, or bay. From that point, it would have only been a matter of time before the recipe moved ashore to become refined in local kitchens — perhaps Aunt Sally’s.

Key lime pie seems to project a commercial presence for the first time in a circa 1930s publication promoting “World Famous Key Lime Pie.” Today it is practically impossible to open a menu in the Florida Keys and not find some form of the dessert on the menu. While there is no definitive proof showing whose menu was the first to offer it, some say Fern Butters, a relative latecomer to the island chain when she arrived on Key Largo in 1926, might have been the one.

Circa 1926, Ed and Fern Butters opened the Key Inn. Clean rooms were provided and home cooked meals offered in the small Key Largo dining room. While Fern was considered an excellent cook, she is most celebrated and best remembered for her dessert — especially her Key lime pie.

The Butters would sell the Key Inn circa 1929 and purchase a 27-room, two-story hotel on Upper Matecumbe called the Russell Arms in 1931. They renamed the business the Matecumbe Hotel and Fern continued to serve her Key lime pie. When the hotel was destroyed in the 1935 Labor Day Hurricane, the Butters moved to California. They returned circa 1943 and built The Fern Inn on the grounds of what was once the Matecumbe Hotel. Fern continued baking her increasingly famous Key lime pies.

As a testament to Fern’s reputation, an article written by Nancy Powell and published in The Key West Citizen on November 1, 1969 began, “For 40 years writers from all over the country have been glorifying the name of Islamorada’s Fern Butters mainly because she more or less ‘invented’ the Key lime pie.”

One of her earliest admirers was Thomas Edison who would bring his friend Henry Ford to enjoy Fern’s cooking. Others included radio and television broadcaster Arthur Godfrey and Harry and Bess Truman. President Eisenhower was also a fan.

Butters would sell The Fern Inn to Manny and Isa Ortiz in 1967, a transaction that included Fern’s famed Key lime pie recipe. Fern, however, would not altogether retire and would later manage the coffee shop and restaurant at The Islander. Meanwhile, The Fern Inn has undergone several subsequent ownerships and some exterior alterations.

The building still stands and is currently home to Islamorada’s MA’s Fish Camp. While the façade of the building has been altered over the course of several decades, the interior of the historic locale retains the original Dade County pine and looks much the same as it did when The Fern Inn first opened making stepping inside the restaurant a bit like stepping back in time. What is cooler still, however, is that MA’s Fish Camp, once home to Fern Butter’s old kitchen, is again producing what just might be the best Key lime pie in the whole of the island chain.

Brad Bertelli is an Upper Keys historian and author of five books on Florida and Florida Keys history. His column will appear every other week in The Reporter. Reach Brad with comments and questions at