Meaning of the word "from the sweetest wine, the tartest vinegar" in English

What does "from the sweetest wine, the tartest vinegar" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

from the sweetest wine, the tartest vinegar

US /frʌm ðə ˈswitəst waɪn, ðə ˈtɑrtəst ˈvɪnɪɡər/
UK /frɒm ðə ˈswiːtɪst waɪn, ðə ˈtɑːtɪst ˈvɪnɪɡə/
"from the sweetest wine, the tartest vinegar" picture

Idiom

a proverb suggesting that the best things or people can turn into the worst if they go bad or are corrupted

Example:
Their friendship ended in a bitter legal battle; truly, from the sweetest wine, the tartest vinegar.
He was once the kindest mentor, but after the betrayal, he became a tyrant—from the sweetest wine, the tartest vinegar.