People strolling down Mackinac Island’s Main Street at night could find themselves doing a double-take after peeking in the windows of the closed fudge shops.

Each night when the crowds thin and the candy-making stores are cleaned and locked up, the fudge-making tables are tucked in tight. They’re covered with electric blankets to keep the marble slabs at exactly the right temperature for the next day’s marathon sessions of crafting the sweet treats.

“Our marble tables are an essential part of the fudge-making process at Ryba’s,” said Eden Callewaert of Ryba’s Fudge Shops. Eden is part of the island’s fudge royalty lineage, as the great-granddaughter of Ryba’s founder, Harry Ryba.

“Marble naturally absorbs heat, making it the perfect surface to cream and cool our fudge. During the day, we rotate between three and four tables to ensure the marble has enough time to cool between batches. Regardless, the marble will heat up slowly during the day as it absorbs in the heat from each batch of fudge.”

So what’s the ideal starting point for the fudge-making tables each morning? The marble’s temperature should be as close to the surrounding air temperature as possible, Callewaert said. If the table is too cold, it can “shock” the molten fudge. This can cause the candy to set up unevenly.

“Since the night air is generally much colder than during the day, electric blankets keep the marble slabs at the correct temperature throughout the night so we can start right back to making the creamiest fudge on Mackinac Island in the morning,” she said.

Hence their nighttime routine, which is also practiced by other fudge shops on the island. Before the Ryba’s staff closes each evening, they use low-powered electric blankets to cover their fudge tables.

“This does not heat the tables but rather maintains the heat present in the marble so each morning starts with lukewarm slabs. With the magic of this seemingly simple innovation, our fudge sets up evenly every time.”

It’s no exaggeration to say that Mackinac Island’s Main Street is synonymous with fudge. The island has 13 fudge shops selling dozens of different flavors. Each summer day, about 10,000 pounds of the rich treat is stirred, poured, cooled and sliced.

You can see the fudge being made as you walk down the street. The marble tables are set up near the shop windows, so the fudge-makers can entertain visitors with their scrape-and-fold precision that creates the long batches of fudge. As you pass by, the air smells like chocolate and sweet vanilla.

To keep up with demand, the island fudge shops import about 10 tons of sugar each week.

To find out more about the history of Mackinac Island fudge, see the island tourism bureau’s story here.

Want to know all the details of Ryba’s Fudge Shops and the family history that brought those stacks of signature pink boxes to Mackinac Island? Check out the family’s new video on YouTube: