Why won’t creamer dissolve in cold coffee?

A STAFF REPORT FROM THE STRAIGHT DOPE SCIENCE ADVISORY BOARD

Dear Straight Dope:

Since moving to Japan four years ago, I've picked up the local custom of drinking iced coffee in the warmer months. Let me get straight to the point, now. Why won't powdered coffee creamer — which mixes lickety-split into hot coffee — mix with cold coffee?

BTW, the most popular powdered coffee creamer in Japan is named "Creap."

SDStaff Cliff replies:

Ah, “Nils,” I’m guessing you didn’t drink coffee when you were a kid —  if you had, you wouldn’t have slept through your science classes. You know, the ones where you learn such basic things as how the solubility of solids in a liquid increases as the temperature of the liquid increases. The main ingredient of creamer is corn syrup solids. In hot coffee these dissolve readily, freeing the next two main ingredients (oil and protein) to form a milky emulsion/suspension in your cup. In “iced” coffee, the sugar solids can’t dissolve nearly as well, so the creamer mix stays in yukky little clumps. Ta da.

Now, why don’t you make a big pot of joe, put in some sugar and half-and-half as God intended, and get cracking on those old schoolbooks. The Japanese have a low enough opinion of us as it is.

Send questions to Cecil via cecil@straightdope.com.

STAFF REPORTS ARE WRITTEN BY THE STRAIGHT DOPE SCIENCE ADVISORY BOARD, CECIL'S ONLINE AUXILIARY. THOUGH THE SDSAB DOES ITS BEST, THESE COLUMNS ARE EDITED BY ED ZOTTI, NOT CECIL, SO ACCURACYWISE YOU'D BETTER KEEP YOUR FINGERS CROSSED.

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