UCC has had black unsweetened canned coffee for quite a while (UCC Black 無糖 sugarless).
Sugarless Japanese canned coffee tends to taste rough because it often includes some robusta beans, which are cheaper and more bitter-tasting. Which is why I prefer the less-sweet (微糖) variants, or with milk/creamer to balance the bitterness. The exceptions are the special cans advertising coffee from a specific country picked by some champion barista or other, which are better, but of course nowhere near as good as a freshly-brewed cup.
What's different about mass-produced coffee in Japan is that it leans heavily towards only mildly bitter coffee, not the hard bitter stuff you might get elsewhere. Convenience-store machine-brewed coffee is almost always pleasant and easy to drink unsweetened, which is not the case in many other countries. Heck, a few years ago the 7-11s here in Singapore brought in 7-11 Japan's coffee machines, but the beans they use here are far more bitter than the ones in Japan.
Sugarless Japanese canned coffee tends to taste rough because it often includes some robusta beans, which are cheaper and more bitter-tasting. Which is why I prefer the less-sweet (微糖) variants, or with milk/creamer to balance the bitterness. The exceptions are the special cans advertising coffee from a specific country picked by some champion barista or other, which are better, but of course nowhere near as good as a freshly-brewed cup.
What's different about mass-produced coffee in Japan is that it leans heavily towards only mildly bitter coffee, not the hard bitter stuff you might get elsewhere. Convenience-store machine-brewed coffee is almost always pleasant and easy to drink unsweetened, which is not the case in many other countries. Heck, a few years ago the 7-11s here in Singapore brought in 7-11 Japan's coffee machines, but the beans they use here are far more bitter than the ones in Japan.