Why does coffee creamer occasionally curdle as soon as it hits hot coffee, but not always?

Question

Anecdotally this happens to me like 1/100 times I pour creamer into coffee. It can happen with cold half-and-half or the pre-packaged single serve pods that are kept at room temperature.

In: 9

Answer 1

As a tip, if you add your milk or cream to the mug first, and then add the coffee, this should happen less often. It’s similar to tempering in egg. You raise the milk’s temperature and acidity more slowly (instead of dumping it into a giant pool of hot acid). Since the final temp and acidity will be less than what is needed to curdle it never crosses that threshold.