Wednesday, March 30, 2011

Cooking Myths (Part 3)

Another cooking myth is that bread is done when you pull it out of the oven.

As any good baker would know this is patently false.

This is a simple consequence of the classical heat equation (bet you weren't counting on partial differential equations showing up on this blog, huh?)

Heat flows from stuff of higher temperature to that of lower temperature.

In the oven, heat flows into the bread because the oven is hotter than the dough.

As you pull the bread out of the oven, the heat starts flowing out of the bread into the ambient air. Frequently, the very center of the bread may be cooler than its surroundings, and heat will keep flowing towards it as well. Consequently, the bread is still "cooking", and experienced bakers know to hold themselves away until the bread equalizes with the temperature outside.

Experienced bakers know that good bread will "crackle" as it cools down. The bread is contracting from being cooled and the strands of gluten are snapping as the bread contracts. Which releases even more aromatic molecules of smell.

That's what makes fresh bread irresistible but you must resist for a while before the bread has cooled down. (Otherwise, you get to eat a lumpy doughy mess.)

It's one of the sad truths of life — instantaneous gratification is a very bad thing in the world of fresh bread!


Brendan said...

True for cake too, which I learned the hard way not too long ago.

ShockingSchadenfreude said...

Steak too. Fish as well.

Experienced chefs pull it off way before the end if they want it rare.

It's just the heat equation applied to any food item.