Posted by: Paul A. Forsyth | March 22, 2014

NPR’s Fresh Air on the Chemistry of Bread

Earlier this week, NPR’s Fresh Air ran an interview with Jack Bishop and Julia Collin-Davison, who are contributors to America’s Test Kitchen. Bishop and Davison were on the program to push their new book, How Can It Be Gluten-Free, which, as one might expect, is a recipe book for preparing gluten-free recipes.

When I heard this interview begin, my instinct was to change the station. I nevertheless listened for a bit, and I was surprised when the guests went into a reasonably detailed and fascinating (to me anyway) discussion of the science of gluten and the chemistry of bread. Here’s a portion:

GROSS: So before we get to some of the gluten-free recipes that you have, what is gluten?

BISHOP: So there are two proteins in wheat, glutenin and gliadin. And they are basically wrapped around starch molecules, and they’re basically inert. But when you add water or another liquid, you are bringing those proteins back to life. And they unwind from the starch molecules and attach to each other. And the more you knead or mix the dough or the batter, the more they will attach to each other, and they form this elastic network that is called gluten.

And the gluten is really what traps the bubbles, the carbon dioxide that is either coming from yeast, from baking soda, from baking powder and is what gives bread, cookies, cake their structure. It helps turn them from doughs and batters into beautiful, risen baked goods.

GROSS: So when you’re using flour that doesn’t have gluten, what are some of the obvious problems you run into?

JULIA COLLIN DAVISON: Yeah, well, gluten is kind of magical. And so when you take it out of the equation, you are left with flours that can’t absorb liquid as well, they can’t absorb fat as well, and they can’t trap those air bubbles that are really crucial for baked goods. So you wind up with things that are either very dense and squat, they’re often greasy, and they crumble apart. They don’t have the binding structure of gluten.

So, you know, baked goods just are a big old mess.

The transcript of the interview is here. Listen here. As I said, surprisingly fascinating. Recommended.

Image Credit: gluten-free bread, photo by Anna, March 2008. Used under a CC BY-NC-SA 2.0 license. Source: Flickr.


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