Not just how, but the overall circumstances. ISTM that a few to several years ago, people started using “salty” as an adjective to describe someone who would have previously been described as bitter. What were the circumstances surrounding this change in English?
Isn’t calling someone salty more mocking than saying bitter? They are so upset that they cry salty tears?
… But I don’t see them as synonymous. I’m a little perplexed.
The usage would be something like this, at least it is here in South Texas.
Old way. “Jerry Jones is still bitter about the Dallas Cowboys losing the 1994 NFC championship game.”
New way. “Jerry Jones is still salty about the Dallas Cowboys losing the 1994 NFC championship game.”
Saltiness is the display of displeasure.
Bitterness is lasting saltiness.
Not synonyms.
How did bad come to mean good?
Do you have some examples?
It seems to me that both adjectives have been in use for quite a while and have quite different connotations.
I’m waiting for up to mean down, myself.
Yep…salty and bitter are not the same.
It’s the same as cranky as opposed to hysterical. It’s a difference of degrees. I believe.
In addition to the above, I’ve heard salty used in the following ways. Names are obviously different, but I’ve heard statements like these made in the most recent, say, 5 years, where prior to that I would have heard people use bitter instead of salty.
“Gertrude is still salty because her husband left her for another woman, even though that was 50 years ago.”
“Jimmy is feeling salty because he lost his bet when the referee made the wrong call at the end of the game.”
“That old man yelled at me for no good reason, I was just knocking on his door to see if he wanted to buy a magazine subscription. He must be salty with the world because things didn’t go his way when he was younger.”
I wouldn’t say salty really means quite the same as bitter in describing attitudes.
Bitter means resentful or cynical or sorrowfully negative.
Salty means more like cross or annoyed. Also it’s very often in response to critique or accusation
Yes, it did,
I’d say that is different adjective completely. IMO salty means “rough around the edges” and unrefined particularly when it comes to language (and swearing)
Though the responses on this thread do answer in the OP. The change in usage was recent enough that it hasn’t made it into the consciousness of the assembled dopers, so like no earlier than 2005 
Sigh. This may be Just Another Example of how useful distinctions can be blurred by uneducated usage of English. Like ‘infer’ vs ‘imply’.
One of our daugters picked up the solecism ‘on accident’ at her daycare from workers there: it took a while to clear that out!
In the long run though, usage determines language.
“Do you want to go to the store?”
- Sure, I’m up for that!
- Sure, I’m down for that!
Salty and bitter have different implications in my mind. Bitter, to me, is a long-lasting negative feeling, whereas salty is more short-term annoyed at something. However, I’m sure there are tons of usages, many of which overlap. They both mean something like “having a negative attitude or reaction”, so there will be overlap.
The difference between “salty” and “bitter” is the flavor of the tears.
I can tell you when the word “salty” suddenly became a way of describing feelings. I did a Google Ngram on “feeling salty”. It jumped between 2004 and 2022, making it about fifteen times as common:
It was unknown in printed English before 1927. That doesn’t mean that it wasn’t ever used in spoken English before then. Sometimes a term can be used in speech before someone happens to use it in print.
“Feeling bitter” is still considerably more common:
I always thought “salty” meant someone crude, as in “salty ol’sailor” or “Ol’Salt”.
I believe that was in usage way before early 1900s
There was a linguistic podcast I listened to recently and it mentioned “on/by accident.” It seems the dividing birth years are about 1975 and 1995. If you were born 1975 or before, you likely say “by accident.” 1995 or later, you likely say “on accident.” In between is a bit of a gradient. I was born 1975, so “by accident” is what I say, but some peers do say “on accident” enough that it’s unnoticed by me.
Well, you do have “up/down for” meaning largely the same thing.