The taste that salt gives to food.
Saltness is usually good because it makes food taste better.
Examples:
I can taste the saltness in the soup.
The saltness of the popcorn is just right.
She doesn't like the saltness of the chips.
The saltness of the ocean water surprised me.
The saltness of the tears made her realize she was crying.
The saltness of the pretzel made me thirsty.