## New Problem: Coffee and Cream

Suppose you have a cup of hot coffee and some cream at room temperature. If you want the coffee to cool to an appropriate drinking temperature as quickly as possible, should you add the cream right away, or wait a while first?

### 4 Responses to “New Problem: Coffee and Cream”

1. Sam Says:

I would add the cream to the hot coffee right away. By adding a lower temperature liquid, you are transferring a part of the heat to the cream and letting the coffee cool down faster.
On the other hand, if you wait to add the cream, the coffee’s cooling is not going to be much faster. Do correct me if I am wrong.

2. Kate Says:

Wait? If you cool the coffee with the cream right away it won’t steam as much (an efficient way to loose heat.)

3. nick Says:

I would wait.

Why, I don’t know… but intuitively, since the cream is at room temperature (and not cold), it’s not gonna make too much of a difference in lowering the heat of the coffee anyway. This is assuming that the cup is not an insulated mug.

4. Vijeta Says:

The Dawson Research Journal had an issue a couple of years ago with an experiment related to this. Enjoy: http://place.dawsoncollege.qc.ca/~drjes/issues/1/coffee.html