curdle

verb3

1. •
   To form curds so that it no longer flows smoothly; to cause to form such curds. (usually said of milk)

   • Too much lemon will curdle the milk in your tea.
2. •
   To clot or coagulate; to cause to congeal, such as through cold. (metaphorically of blood)

   • "Vich Ian Vohr," it said, in a voice that made my very blood curdle, "beware of to-morrow!" — 1814
3. •
   To cause a liquid to spoil and form clumps so that it no longer flows smoothly.

   • It is enough,' said the agitated Mr. Slurk, pacing to and fro, 'to curdle the ink in one's pen, and induce one to abandon their cause for ever.' — 1836