Monthly Archives: November 2022

And Walnuts Can Sulk

Pistachios can spontaneously combust.

It turns out there’s a price to pay for how good pistachios are: Under the right circumstances, they can spontaneously combust. Everyone’s favorite shelled nut is especially rich in fat, which is highly flammable. Thankfully, that only becomes a problem when pistachios are packed too tightly during shipping or storage. It’s important to keep the nuts dry lest they become moldy — but if they’re kept too dry and there are too many of them bunched together, they can self-heat and catch fire without an external heat source. 

Though exceedingly rare and easy to avoid if the proper instructions are followed, pistachio self-combustion is a real enough concern that the German Transport Information Service specifically advises that pistachios “not be stowed together with fibers/fibrous materials as oil-soaked fibers may promote self-heating/spontaneous combustion of the cargo.” Don’t worry, though: It won’t happen in your pantry with just a few bags, which means you can indulge in the nut of your dreams without worrying about their flavor becoming unexpectedly smoky.

Happy Gobble Gobble!


Evidentialism factslap: Sweet potatoes aren’t actually potatoes.

Sweet potatoes and common potatoes share part of a name and the spotlight at Thanksgiving meals, but the two are entirely different plants — and sweet potatoes aren’t even potatoes. While both root vegetable species are native to Central and South America, they’re classified as unrelated. Sweet potatoes belong to the Convolvulaceae family, a group of flowering plants that’s also called the morning glory family. Potatoes belong to the nightshade (Solanaceae) family, and are cousins to peppers, tomatoes, and eggplants. 

Both species get their name from an Indigenous Caribbean term, batata, which eventually morphed into the English “potato.” By the 1740s, “sweet” was added to the orange-fleshed tuber’s name to differentiate the two root crops.

Then there are yams. Although they’re often served interchangeably with sweet potatoes at Thanksgiving dinners, this third root crop is biologically unrelated to either sweet potatoes or common potatoes. These tubers belong to the Dioscoreacea family, a group of flowering plants usually cultivated in tropical areas. Luckily, you don’t have to know their scientific classification to distinguish between the two non-spuds at the grocery store: Sweet potatoes have tapered ends and relatively smooth skin, while true yams are generally larger with rough bark and a more cylindrical shape. At most U.S. grocery stores, what you’re seeing labeled as a yam is probably actually a sweet potato.