Bishop and Collin Davison edited The How Can It Be Gluten Free Cookbook. They join Fresh Air to share tips, secrets and favorite recipes for gluten-free baking.

Interview Highlights

On what gluten is and does

Bishop: 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.

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

On common problems with gluten-free foods

Collin Davison: Gluten is kind of magical, and so when you take it out of the equation, you're 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 ... very dense and squat; they're often greasy and they crumble apart. They don't have the binding structure of gluten.

On the best store-bought gluten-free flour

Collin Davison: The one that we found worked best universally — and that means in cookies, in bread dough, in biscuits, in muffins — was King Arthur Flour gluten-free blend. And it is very much like, actually, our recipe for gluten-free flour blend (see recipe below) in that it uses two types of rice flours — white and brown — and it also uses two types of starches, which is potato and tapioca. And those four ingredients, we found, were really the magic key to finding a blend that worked almost as good as a wheat flour.

On the best gluten-free pasta

Collin Davison: We tested every brand of gluten-free pasta we could get our hands on. We tested it plain, we tested it with sauce, and one brand really rose to the top, again, in terms of its texture and flavor, and that brand is Jovial ...

A lot of the brands came out really mushy; they didn't have enough texture. Of course, you'll never get gluten-free pasta that's al dente, but the Jovial came as close to al dente as you can get. Also, it didn't have any "off flavors" which is a bonus in this world of gluten-free products. And ... it actually tasted more like traditional wheat pasta that any of the other brands we tried ...

Bishop: You could tell what the pasta was going to taste like by looking at the water in the pot. The real problem with any gluten-free pasta — whether it's made of corn, quinoa or brown rice, which is what the Jovial is made of — there isn't enough structure to contain the starches that are in the pasta ...

The Jovial has more protein and more fiber. And basically what that does is it prevents the starch molecules from bursting. During the cooking process, the starch is hydrating and swelling, which is a good thing, so that it goes from its dry state to something that you can actually eat. But in a lot of the other gluten-free pasta brands that we tested, the starches kept on swelling and eventually they exploded, and you could look in the pot and see the starches because the pasta water was now cloudy — it basically looked like milk.

On foods that are impossible to make gluten-free

Collin Davison: I'll never say never because I always like a good challenge. ... Gluten-free phyllo dough — not something I think we can do — and a gluten-free puff pastry. That one — big question mark ...

Bishop: I think a croissant would be pretty hard to make gluten-free ... in large part because of the butter issue, which is the flour has so much trouble absorbing fat and you really don't want a low-fat croissant.

On the trick to making gluten-free sugar cookies

Collin Davison: You're dealing with the maximum amount of butter and sugar, and that's what gives a traditional sugar cookie its flavor. So [in the gluten-free version,] you can't use all that butter because it just leeches out and what you wind up with is fried cookies on the baking sheet, which are pretty disgusting. The other issue is that ... they'll just spread as much as they want, as much as they're allowed. ... When you're dealing with gluten-free batter or gluten-free cookie dough that doesn't have a lot of binders, it will just spread and spread ...

The solution ... was when you take out the sugar and you take out the butter and you take out all that flavor, you need to replace it with a different kind of flavor and fat that will stay in the cookie and the fat won't leech out during baking — and that turned out to be almonds. When you think about almonds, it has a lot of natural fat in it, and those almonds will hold onto their fat and their flavor in the oven. ... So almonds, or almond flour, was the key to the sugar cookie, along with xanthan gum [as a binder].

Dark Chocolate Cupcakes

Why This Recipe Works

The ultimate chocolate cupcakes are moist and tender with rich chocolate flavor. Taking a cue from the success of our moist and tender Chocolate Layer Cake, we scaled the recipe to fit in a standard 12-cup muffin tin and simply adjusted the baking time. The combination of rich chocolate flavor and light, fluffy crumb once again fooled tasters into thinking these cupcakes couldn't possibly be gluten-free. Once frosted, serve the cupcakes within a few hours.

Dark Chocolate Cupcakes. Courtesy of America's Test Kitchen

Makes 12 cupcakes.

1/2 cup vegetable oil
3 ounces bittersweet chocolate, chopped
1 ounce (1/3 cup) unsweetened cocoa powder
3 1/2 ounces (3/4 cup) ATK Gluten-Free Flour Blend (see recipe below)
3/4 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon xanthan gum
1/2 teaspoon salt
2 large eggs
1 teaspoon vanilla extract
5 1/4 ounces (3/4 cup) sugar
1/2 cup whole milk
2 cups frosting

1. Adjust oven rack to lower-middle position and heat oven to 350 degrees. Line 12-cup muffin tin with paper or foil liners.

2. Microwave oil, chocolate, and cocoa together in bowl at 50 percent power, stirring occasionally, until melted, about 2 minutes. Whisk mixture until smooth, then set aside to cool slightly. In separate bowl, whisk flour blend, baking powder, baking soda, xanthan gum, and salt together.

3. In large bowl, whisk eggs and vanilla together. Whisk in sugar until well combined. Whisk in cooled chocolate mixture and milk until combined. Whisk in flour blend mixture until batter is thoroughly combined and smooth.

4. Using ice cream scoop or large spoon, portion batter evenly into prepared muffin tin. Bake until toothpick inserted into center of cupcakes comes out clean, 16 to 18 minutes, rotating muffin tin halfway through baking. Let cupcakes cool in muffin tin on wire rack for 10 minutes. Remove cupcakes from tin and let cool completely, about 1 hour. (Unfrosted cupcakes can be stored in airtight container at room temperature for up to 1 day.)

5. Spread or pipe frosting over top of cupcakes and serve.

Excerpted from The How Can It Be Gluten Free Cookbook. Excerpted by permission of America's Test Kitchen.

Chocolate Chip Cookies

Why This Recipe Works

We started our testing by swapping in our flour blend for the all-purpose flour in a standard Toll House cookie recipe. It was no surprise that these cookies had problems: They were flat, sandy, and greasy. We'd discovered during our baked goods testing that gluten-free flour blends simply can't absorb as much fat as all-purpose flour can, so cutting back on the butter helped to minimize greasiness. Less butter, along with some xanthan gum, also helped alleviate the spread issue, so the cookies didn't bake up so flat. As for the sandiness, we knew from our gluten-free muffin testing that fixing this problem required a two-step approach. The starches in our blend needed more liquid as well as more time to hydrate and soften, so we added a couple tablespoons of milk and let the dough rest for 30 minutes. This resting time also had a secondary benefit: It gave the sugar time to dissolve, which led to faster caramelization in the oven. And that meant a cookie not just with deeper flavor, but also with a chewier center and crisper edges. Finally, we wanted our cookies to be less cakey and more chewy. We realized creaming the butter, as the original Toll House recipe directs, was aerating the butter too much. Melting the butter instead, and changing the ratio of brown sugar to granulated sugar, gave our cookies the right chewy texture. The extra brown sugar also gave our cookies a more complex, toffee-like flavor. Bite for bite, this was a chocolate chip cookie that could rival the best versions of the classic. Not all brands of chocolate chips are processed in a gluten-free facility, so read labels carefully.

Chocolate Chip Cookies. Courtesy of America's Test Kitchen

Makes about 24 cookies.

8 ounces (13/4 cups) ATK Gluten-Free Flour Blend (see recipe below)
1 teaspoon baking soda
3/4 teaspoon xanthan gum
1/2 teaspoon salt
8 tablespoons unsalted butter, melted
5 1/4 ounces (3/4 cup packed) light brown sugar
2 1/3 ounces (1/3 cup) granulated sugar
1 large egg
2 tablespoons milk
1 tablespoon vanilla extract
7 1/2 ounces (11/4 cups) semisweet chocolate chips

1. Whisk flour blend, baking soda, xanthan gum, and salt together in medium bowl; set aside. Whisk melted butter, brown sugar, and granulated sugar together in large bowl until well combined and smooth. Whisk in egg, milk, and vanilla and continue to whisk until smooth. Stir in flour mixture with rubber spatula and mix until soft, homogeneous dough forms. Fold in chocolate chips. Cover bowl with plastic wrap and let dough rest for 30 minutes. (Dough will be sticky and soft.)

2. Adjust oven rack to middle position and heat oven to 350 degrees. Line 2 baking sheets with parchment paper. Using 2 soup spoons and working with about 11/2 tablespoons of dough at a time, portion dough and space 2 inches apart on prepared sheets. Bake cookies, 1 sheet at a time, until golden brown and edges have begun to set but centers are still soft, 11 to 13 minutes, rotating sheet halfway through baking.

3. Let cookies cool on sheet for 5 minutes, then transfer to wire rack. Serve warm or at room temperature. (Cookies are best eaten on day they are baked, but they can be cooled and placed immediately in airtight container and stored at room temperature for up to 1 day.)

Excerpted from The How Can It Be Gluten Free Cookbook. Excerpted by permission of America's Test Kitchen.

The America's Test Kitchen Gluten-Free Flour Blend

Makes 42 ounces (About 9 1/3 cups)

Be sure to use potato starch, not potato flour. Tapioca starch is also sold as tapioca flour; they are interchangeable.

24 ounces (4 1/2 cups plus 1/3 cup) white rice flour

7 1/2 ounces (1 2/3 cups) brown rice flour

7 ounces (1 1/3 cups) potato starch

3 ounces (3/4 cup) tapioca starch

3/4 ounce (3 tablespoons) nonfat milk powder

Whisk all ingredients together in a large bowl until well combined. Transfer to airtight container and refrigerate for up to 3 months.

Excerpted from The How Can It Be Gluten Free Cookbook. Excerpted by permission of America's Test Kitchen.

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