Brunost

Norwegians buy a special slicer just to eat their brunost. This “brown cheese” has a texture more like fudge than cheddar and a salty-sweet, almost tangy flavor.

Brunost is essentially leftover whey from the cheesemaking process that’s been simmered into a sweet, caramelized paste, and left to harden. Diners slice into the finished product and serve it over rye toast, crisp bread, and waffles. It’s often paired with strawberry jam, in a flavor combination resembling peanut butter and jelly.

Despite being sweet and caramel-y, brunost has a lot in common with Marmite, a savory brown British spread. At a basic level, both are regionally distinct toast accoutrements. Like brunost, Marmite is a point of pride in its country of origin, and fans eat it at breakfast, lunch, and tea time. They’re also both byproducts of another food manufacturing process (though Marmite derives from beer brewing).

But brunost likely stands out among other bread toppers when it comes to destructive capacities. In 2013, nearly 60,000 pounds of brunost caught fire in a truck barreling down a tunnel in northern Norway. The fatty, caramelized lactose—which a Norwegian police officer likened to petrol—burned for more than four days. Officials couldn’t enter the tunnel due to toxic chemical levels, and it remained closed for weeks. One member of the Public Roads Administration said, “I didn’t know that brown cheese burns so well.”