Did You Know? Taiwan’s Convenience Stores Sell 40 Million Roasted Sweet Potatoes a Year

Walk into almost any convenience store in Taiwan on a chilly evening and there’s a smell that gets you before the automatic door finishes its chime: roasted sweet potato (烤地瓜). Somewhere near the counter there’s a little warming cabinet piled with them, skins cracked and sticky, flesh glowing orange. Grab one with the tongs, drop it in a paper bag, and you’ve got the island’s most humble winter snack in your hands.

Here’s the part most people don’t know: nearly all of those sweet potatoes are the same variety, and it was bred 70 years ago.

Meet Tainung No. 57

The sweet potato in the cabinet is almost always Tainung No. 57 (台農57號), bred in 1955 at the Chiayi branch of Taiwan’s Agricultural Research Institute. Breeders crossed a high-starch Taiwanese sweet potato with a better-tasting American one, then picked No. 57 out of about 1,000 offspring.

It has never really been replaced. Taiwan’s breeders have numbered varieties all the way up into the 70s, yet No. 57 still covers around 80% or more of the island’s roughly 10,000 hectares of sweet potato fields. Growers like it because it yields reliably and suits Taiwan’s subtropical climate. Eaters like it because it’s dense and fluffy rather than watery, with a deep, honeyed sweetness when roasted. It survived serious disease outbreaks along the way, too, with the institute stepping in each time with virus-free seedlings and field guidance to keep it alive.

40 Million a Year

For decades, sweet potatoes were humble farm food in Taiwan, grown through lean years and partly to feed pigs. The big glow-up came when they moved into convenience stores. According to Taiwan’s Ministry of Agriculture, the four major convenience store chains now sell about 40 million roasted sweet potatoes a year, and busy branches can sell out by early afternoon. (If you’ve read about how dense Taiwan’s 7-Eleven network is, the number starts to make sense.)

Look for the cold twist too: 冰烤地瓜, “ice-roasted” sweet potato. It’s the same potato, roasted slowly and then chilled fast, and it sits in the fridge case instead of the warmer. Eaten cold, it’s almost like a dessert.

The Island Is a Sweet Potato, Too

There’s a reason this snack feels personal. Look at a map and Taiwan’s main island is shaped a lot like a sweet potato, and Taiwanese people affectionately call their island 番薯, the sweet potato, as our Taiwan map guide explains. The name even turns up in wildlife: the park-lawn heron we met yesterday has the nickname 地瓜鳥, the “sweet potato bird.”

How to Do It Like a Local

• Use the tongs and the paper bag. They’re usually right next to the cabinet. Pick one, bag it, and pay at the counter.
• Look for the cracked ones. Sticky, caramelized juice leaking from the skin means it has been roasting long enough to turn syrupy.
• Eat the skin or don’t. Nobody judges. Many people peel back the top like a banana and eat it straight from the bag while walking.
• Want the charcoal version? Night market and street-cart sweet potatoes are a different experience. They’re a winter staple in our Taiwan desserts guide.

It’s cheap, it’s healthy-ish, it’s warm in your hands on a damp November night, and it comes from a potato older than most of the people buying it. Very Taiwan.

If convenience-store life is your love language, our Family Mart Taiwan logo tee is a good one to wear on your next late-night sweet potato run.