That's interesting, it's something I haven't really thought about.
There is some desire for less caffeine as it adds bitterness. Eugenioides, a parent species to arabica the commonly cultivated species, inherently has less caffeine and is said to have a remarkably sweet cup. It's had some attention in barista competitions in the last few years.
When you say sweet, is that because the coffee has more sugar, or are there just other compounds?
I guess what I’m asking is what’s the difference between what you’re describing and making a regular good cup of coffee and adding a teaspoon of sugar?
It's the "other stuff"/flavor compounds, definitely.
I don't think brewed coffee contains any meaningful amounts of sugar?
Coffee (filter/brewed, not espresso) is ~98.5% water by weight, even if the Eugenioides species has more sugar in the beans than Arabica (it might! literally no idea here) — if the difference would be "just" down to the sugar levels, I don't think it would be noticeable at the dilution levels we're talking about.
The difference in the natural sweetness vs adding sugar is an interesting question, honestly!
Sugar is usually added to coffee to hide/mask/round out the bitterness; whether naturally occurring or from overly developed roast. But it also masks/drowns out other notes, too. You'll get less bitterness, but less of the acidity, the floralness, of all the other subtleties that can make coffee great — you'll get _sugar_ sweetness (and it's a very different kind of sweetness than coffee can naturally have!), and less of everything else.
Eugenioides is different because it just doesn't have that baseline note of bitter/hashness _at all_, and it's naturally pretty sweet.
Instead of sugar, I think the "magic berries" (I never tried!) that mess with your bitterness perception might work better? I'm actually now curious to try it out...
Eugenioides is sweet in a way that no other coffee I ever had is sweet.
You sometimes see "sweet" as an axis of flavor of coffee, or as a tasting note on a bag of fancy beans; but eugenioides is very different.
It's _the_ dominant note in that cup, and it is much less fruity or floral, it's just... sweet. You taste the sweetness, and then the rest of the "typical" coffee notes come in the background, but much less pronounced than usual.
I've seen people describe it as a "cereal-like", and while I don't think I fully agree with that description, I do get where they're coming from.
If you're a coffee person and ever see a bag of it on offer (and can afford it), I definitely recommend grabbing it — it's really, really unique (and quite rare!).
(And I do not think this is in any way related to the caffeine content — otherwise most of decafs would be very sweet, and they obviously aren't).