Why are chestnuts roasted?

That is, are they no good raw, or what?

(I live in Florida, BTW, I’ve never eaten a chestnut in my life; but for some reason they have this cultural presence around Christmastime.)

They’re technically edible raw, but they don’t taste very good.

Because they taste good that way?

Why do we toast bread?

Not really, no. They taste kinda flour-y if they’re not roasted. In fact, they can be dried and made into flour. My mother likes them boiled, with a bay leaf. I think, no matter how they’re cooked, they’re still flour-y. But roasting does bring out a nice flavor. I’ve experimented with roasting, then boiling. That’s pretty nice. Roasted flavor with … hydrated, soft, moist … flour-y-ness. Bit more work than a wintertime niche food actually deserves, however.

I occasionally eat some raw, but it doesn’t mean that they aren’t somewhat toxic eaten this way. I wouldn’t know.
And as already mentioned, they’re fine boiled.

On the street in Singapore they roast chestnuts in a giant wok filled with coffee beans! Mmmmmm!

Chestnuts are cooked in various ways for the same reason potatoes are cooked. They are starchy and don’t taste good raw.

There are plenty of foods that many humans find more appealing cooked than raw. Examples include potatoes, asparagus, squash, turnips, corn and onions.

Quoting you because you have the best list–all of those are fine raw and some people prefer them raw. Well, maybe not squash.

I’m guessing (no knowledge) that raw chestnuts are like raw peanuts. Perfectly fine but more easier to chew and more flavorsome roasted.

Oak acorns actually have something vaguely or actually toxic in them and have to be retted (probably not right word) if eaten–maybe chestnuts have that but I don’t think so.

My hypothesis: Otherwise all that “open fire” goes to waste!

I love that song:

Jack Frost roasting on an open fire… chestnuts shoved up his nose…

Is that how it goes?

Well, it’s just that I’ve never heard of any other nut that is deemed to require cooking. Generally speaking, nuts are eaten raw. [insert your own teabagging joke here]

My mother’s version was:
*“Children roasting on an open fire… Jack Frost nipping at their toes.” *

Carry on.

Just personally – yet another reason for me to resolve never, ever to visit Singapore…

Chestnuts could be heavy-going if you didn’t peel them first…

The French and Italians go more for chestnuts than others ( marrons or castagna ), and export products such as Marron Glacé or canned puréed chestnut paste; but I haven’t heard of them snacking on the nut itself.
I found an eHow guide to eating them raw: it seems to involve soaking in hot water then roasting them, which is a new definition of ‘raw’.

A lot of chestnuts are slightly bitter raw. Maybe roasting them mutes the bitterness somewhat. I’ll eat them once in a long while. ETA: Its relative, the buckeye, is intensely bitter, so not edible for most folks.

Aren’t cashews posionious without some form of processing? (top hit on google says yes)

Raw chestnuts are inedible. Roasting them makes them sweet and tasty.

Right - but as I noted, many (probably most) people prefer them cooked. Of the total portions consumed of all these veggies, I’d guess at least 98% are cooked.

It’s the shell that’s poisonous.

Oh, absolutely. I just had a thought about cooked/raw vegetables segueing into ‘roasting to make edible,’ and you had a great list.

Still can’t recall any squash I 'd eat raw.