The red gum that's just pure cinnamon or something. Plus it's spicy. Ew. Just ew

Black Death. Tastes like I’d expect a chemical burn to taste.

I’m seeing a lot of black licorice mentions, but there’s a special hell for Läkerol’s menthol black licorice.

Related anecdote: When I worked an offshore rotation with people from all over the world, I made an effort to bring candy that I'd never seen outside of Scandinavia. It was always amusing to see people sampling candy I liked when they weren't used to the ammonium chloride branch of flavors.

And once I brought this:

Everybody who weren't Norwegian, Swedish, or Finnish (sadly we had no Danes on board) absolutely hated it. Especially the Americans and Brits.

Everyone except Mario, that is; a Croatian geophysicist. He loved them. His voice still lives rent free in my head over ten years later, saying "Sweet candy is for kids"

A few trips later I brought one of my favorites for basically the same result, but this time with Jim (from Illinois, iirc) complaining that it made his mouth physically hurt:

Mario loved that one even More.
The only thing everyone on board liked was the obscene amount of chocolate my navigator brought every trip.

But to answer the question: Twizzlers. I bought some when visiting the US a couple of years ago. It tasted like oily sweetener (as in, clearly not actual sugar). That's when I learned that American and European wine gum are flavored very differently.

Footnote: Durian and durian chocolate is quite alright once you get used to the slight farty smell from each packet you open.

American or South African chocolate products.

NOT an anti-American/-Saffer thing. They add butyric acid, which tastes like vomit to the rest of the world. (Accurate, as vomit contains it).

Presumably because the market there have been trained to expect that flavour for some reason. To the rest of us, a US or ZA origin is usually a sign to avoid.

I got a monthly food box for my wife a number of years ago. Each month they sent snacks from a different country.

I can't remember which country it was from, but one month we got some round, hard candies. It was one of the most unfortunate things I have ever intentionally put into my mouth.

I don't even remember the flavor (licorice, maybe?), because my brain attempted to bleach it out.

Everything else was usually tasty, though.

Swede here.

Some American candy, mostly bad chocolate

When I was a kid someone gave me a "buttered popcorn" flavored dum-dum sucker. It tasted so terrible that it gave me a taste aversion to real buttered popcorn for nearly 2 decades.

At my place of work, one project we worked on involved a lot of contractors from a place based in China. (The project was an absolute cluster-fuck all the way from soup to nuts, but that's a story for another day.) When the project concluded, they sent our office a thank-you gift box of various Chinese snacks.

One of the snacks was a... dried... meat... "candy"... I guess? The taste wasn't "sweet" so much. It tasted like it had been dipped in perfume. And the texture of the meat was hard to describe. Not chewy like jerky, and it didn't have that highly-processed Slim Jim sort of texture to it. Maybe it was sortof freeze-dried or something? I also couldn't identify what animal the meat might have come from. (And I couldn't read the text on the packaging.)

I'm not sure whether it was just an acquired taste or rather a practical joke by the folks at the Chinese company. Lol.

Salted liquorice.

I had a Norwegian friend who waxed lyrical about this stuff. So when I saw it for the first time in a shop, I grabbed a packet to nibble on while waiting for my train.

Plain black liquorice is delicious and salt makes everything taste better, and the Norwegian seemed like a nice, relatively normal person who enjoyed other things I liked. This was a low risk choice of mid morning snack, I thought to myself.

I was wrong. So very wrong.

This stuff tastes like it was peeled off the bottom of a shoe after walking through the city all day. It's not salt either, it's freaking ammonium chloride.

To paraphrase the Wikipedia:

The mineral is commonly formed on burning coal dumps from condensation of coal-derived gases. It is also found around some types of volcanic vents. It is a product of the reaction of hydrochloric acid and ammonia.

And Scandi's put this on liquorice and like it. Even the kids. Madness. It took my all not to heave into a bin after trying it and like six cups of black tea to get the taste out of my mouth.

I gave the Norwegian the rest of the packet and he laughed at me while I watched him eat it because I looked so horrified.

The cheap no name "chocolates" that taste like eating oil solids disguised as chocolate

I tried some matcha mochi once. It didn't really taste good, but the worst thing about it was that it was just boring.

I haven't actually tried this but my friend did.

One Halloween as a kid we got gummy false teeth. It looked exactly like how you think it would look. I cant actually remember how it tasted, but it want good. Second was some sugar free sour patch kid clones, they mostly tasted like soap.

That's an easy one - Durian bonbons from China. Durian is also known as the "stink fruit". You need many hours to get that taste out of your mouth

Hersheys "chocolate". I spit it out, and a bit embarrassed, asked "could it gone bad during the flight?"

Well, obviously this stuff does taste like vomit, and Americans seem to be OK with that. Explains a lot about American behavior. If chocolate here would taste like that, we probably would have more mass shootings, too.

I tried Hershey's (American chocolate) before and it tasted absolutely disgusting. it will never ever come remotely close to Dairy Milk or Galaxy

If I had to choose between leather belt flavoured licorice and vomit flavoured Hershey's. Licorice wins everytime.

Can't stand corn fructose and palm sugar based snacks. Terrible everything - engironmental impact, texture, health impact, flavor. It's just the cheapest possible option that ruins everything it touches.

NECO wafers. Like cardboard they taste

The Harry Potter bean things which has awful flavors mixed in, like puke etc.

Hands down absolutely nothing worse than peeps. They somehow manage to make twizzlers taste like ultra gourmet candy.