I’ve read several things and seen references to keeping otter fur wet before put up, I presume to prevent singe? I haven’t had any problems that I noticed with dry otter, but why the emphasis? Do you just keep wetting it and then put it on the board wet?
Does otter fur that dries out on a live otter singe as well? Seems strange. Any insight appreciated.

Dampen the guard hair.It is the guard hair that can singe.
Most singe is caused by dry heat (hanging an animal near a wood stove),or bright sunlight in spring on live otter.
Some trappers scrape otter on a beam after rough skinning,If pushing hard instead of slicing lightly with the fleshing knife dry fur on the dry beam can singe.dampening the beam and the guardhair will help to alleviate that particular problem.
Not an issue for trappers who frostscrape, clean skin,or flesh over their knee with a victorinox skinning knife.
Early and late caught otter often have naturally singed fur not caused by fur handling.
Singe is a problem with Otter because the guard hair has an oval crossection not round like other furbearers.
Singe is normally a downgrade but the price difference may be negligable depending on the end use for the fur.
Prime otter are often plucked and sheared so a manufacturer that is using them for that purpose will pay good money for heavy otter even if singed.

Most otter are singed before you catch them.
How does an otter get singed when drying by heat? It seems to me with the fur in when drying how does heat effect the fur?

Well, I got to get to the deer woods.

Singe shows up in the window and tail.
Hanging to dry in the wrong environment before skinning and boarding is the culprit.
I hang all my otter to dry slowly in the cold room.

Here is a test you can do beav,take a good strait hair grade otter skin with no singe,dried and off the board,and store it in your attic over the summer,then open it up next winter and see it all singed.

I have opened up a few for tanning like that.

And who dries otter in the attic for the whole summer? That's no test.

No one-just an example of the many ways otter fur can singe albeit an extreme example.
You asked how an otter singes from heat.I may have misunderstood when you alluded to otter not singeing by poor handling.
Obviously poor handling will result in singe in an otherwise Straight hair grade otter.

That makes sense. So if I dry it with snow and then just keep it cool and am careful on the beam I’ll be fine sounds like. Thanks for the replies.

Drying with snow and hanging in a cold room like a root cellar in the house until ready to skin and your good.
Best to dry pelts at a cool temp too (and low humidity).
Where I am my root cellar stays at about 10c all winter and the humidity here in winter is very low.
Beaver and otter dry in there in 3 or 4 days if scraped on a beam or cleanskinned.If frost scraped they dry in half that time.

I roll them in snow and hang them nose down in my shed until I'm ready to skin and flesh. I still use a spray bottle to keep the fur and the beam moist, but it's just something I've always been told to do, not sure wether it's helping at all. Doesn't seem to hurt anything either though

So, I'm to believe that heat causes singe. How much heat Is created during the fleshing process?
Or is it the movement of the hide while the hide is being fleshed? I can't see where any of that creates singe. In my opinion there isn't any heat created when the hide Is being fleshed. And when your fleshing you might move the hide 5 or 6 times to get the job done. But once the hide is moved and in position it's not being moved around. Anyway, when I'm fleshing an otter, it's not moving.
I think an otter that ends up singed Is already beginning to singe. And no matter what you do that otter will end up being singed.

Sounds like you singed a bunch of otter .

That would be a no.
You're not explaining the reason for wetting the fur down. You keep saying that heat creates the singe. But in my opinion fleshing doesn't create any heat.

I explained it agressive pushing on the knife creates friction between dry fur and dry beam which creates both heat and pressure on the flat guard hairs like pulling a hair across your fingernail it will curl without heat.
Clean skinning,fleshing over the knee or slicing lightly with a sharp fleshing knife wont create the friction like hard pushing does.
Improper storage and drying before and after skinning can also cause singe.
And yes some otters are singed before they get in your trap.
Nothing you can do about that - BUT remember - you cant turn a 10 dollar otter into a 50 dollar otter but you can turn a 50 dollar otter into a 10 dollar otter.

The only true test would be to have a critter graded before fleshing, and then after. I wish I knew more about the quality of fur, because I think I finish more than I should because of my ignorance (not otter though, they're finished regardless).