I like butter on my bagels. So does Jan Polanik. According to the New York Times, he filed a pair of class-action lawsuits after paying a quarter for butter every time he ordered bagels over a four year period, but was given margarine without being told.

Dunkin’ Donuts franchise owners settled the suits, but not until after using food safety as a defense.

In 2013, a Dunkin’ Donuts spokeswoman, Lindsay Harrington, offered an explanation for why a vegetable spread might be used.

“For food safety reasons, we do not allow butter to be stored at room temperature, which is the temperature necessary for butter to be easily spread onto a bagel or pastry,” she told The Boston Globe. The recommended procedure in the store, she said, was for individual whipped butter packets to be served on the side of a bagel or pastry, but not applied. “The vegetable spread is generally used if the employee applies the topping,” she said.

I’m not sure what the food safety reasons are since the salted version (over 1.5%) of oil-in-water emulsion doesn’t support the growth of foodborne pathogens – or staph toxin formation -and remains safe at room temperature when the power goes out.  Stuff will persist, including Listeria, but temperature control isn’t a factor. It’s a quality thing.