Mmmm . . . Doughnut Perfection

By Fenella Saunders|Wednesday, November 01, 2000
RELATED TAGS: NUTRITION


What makes the Homer Simpsons of the world slaver for a doughnut? The key lies in the frying oil, says chemist Gerald DeMenna of Chem-Chek, a consulting company in New Jersey. After 50 to 75 hours of frying, heat and steam make parts of cooking-oil molecules break off into free fatty acids. The acids combine with the minerals and salts in dough to form alkalines— soap, in other words— that allow the hot oil to permeate a thin outer layer of dough. That layer quickly cooks into a crispy crust that seals the interior so that it steam-cooks and remains moist. New oil lacks the crucial breakdown products, so it leaves doughnuts pasty white and dry. "But in an abused oil, there's so much soap that the doughnut gets saturated with oil," DeMenna says. To get things just right, doughnut makers can seed new oil with samples taken from aged batches, or purchase broken-in oil previously used to fry foods such as potato chips.

 
Comment on this article
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT
ADVERTISEMENT
Collapse bottom bar
DSCDecCover
+

Log in to your account

X
Email address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it emailed to you.

Not registered yet?

Register now for FREE. It takes only a few seconds to complete. Register now »