TLDW: Their mandarin orange wine was a bit too bitter. Testing, unscientifically, if they can tell a difference. They can. They think it lowers the bitterness.
Interesting. I’m mainly a beer brewer (only my first cider recently) so I’ve not had a brew that’s “too bitter”, as with beer you WANT them to be bitter, usually. I’ve heard to add a pinch of salt to a pot of coffee.
I remember hearing about salt and bitterness a while back and trying it with some tonic water. Definitely works, but I think it might just be a matter of our senses getting confused. I wouldn’t add that much salt as to mask bitterness in beer though, I fear it may screw up the fermentation.