not one's cup of tea

cup of tea

1. Something one prefers, desires, enjoys, or cares about. Often used in the negative to mean the opposite. I invited you because I thought long-distance cycling was your cup of tea. When I found out that reading wasn't his cup of tea, I knew that there wasn't much of a relationship in store between us.
2. Something to be addressed or managed. She did finish all of her chores, but her homework is another cup of tea altogether.
See also: cup, of, tea
Farlex Dictionary of Idioms.

cup of tea

n. something preferred or desired. (Often negative.) Driving children around all afternoon is not my cup of tea.
See also: cup, of, tea
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

cup of tea

1. Something that one excels in or enjoys: Opera is not my cup of tea.
2. A matter to be reckoned or dealt with: Recreational sport is relaxing. Professional sport is another cup of tea altogether.
See also: cup, of, tea
American Heritage® Dictionary of the English Language, Fifth Edition.

not one's cup of tea

It doesn’t suit one, it isn’t to one’s taste. The ultimate origin of this term is not known, although it definitely is British. Tea had become an immensely popular beverage in Europe by the mid-eighteenth century, and the positive version—he or she is my cup of tea—was used from the late nineteenth century. The negative is slightly newer, from the 1920s. Josephine Tey used it in The Franchise Affair (1948): “Probably she isn’t your cup of tea. You have always preferred them a little stupid, and blonde.”
See also: cup, not, of, tea
The Dictionary of Clichés by Christine Ammer
See also:
  • cup of tea
  • cup of tea, one's
  • be not (one's) bag
  • (one's) bag
  • bag
  • be not (one's) cup of tea
  • (one's) jam
  • better late than never
  • eat one's cake and have it (too)
  • eat one's cake and have it, too