How to bake with nut flours for gluten-free treats

If you’ve ever dabbled with gluten-free or paleo baking, or enjoyed chewy amaretti or a tender financier, chances are you are already a fan of almond flour. But almond flour is only one small star in the nut flour universe.

Lesser-known flours made from finely ground walnuts, pecans, hazelnuts, pistachios and chestnuts, among others, are nutrient-dense and full of flavor, and they add personality to whatever you are baking or cooking. They also tend to be on the pricey side, so before you line your cupboards with bags of nut flour, it’s crucial to understand how they compare to grain-based flours, and what they can and cannot do. Read on to learn more about nut flours and the best ways to incorporate them into your recipes.

What are nut flours?

Nut flours are whole nuts that have been ground into a fine, flour-like powder. Many store-bought nut flours are made with blanched nuts that have had their skins removed. Blanching the nuts before grinding gives the nut flour a fluffy texture and light color that resembles all-purpose flour. Nut flours are closely related, but not identical, to nut meals, which are rarely blanched and typically more coarsely ground. Flours and meals made from the same type of nut (say, almonds) can often be used interchangeably in a recipe. But the texture and color of the dish may differ, with nut meals delivering slightly darker and denser results. Smart tip: It’s best to store nut flours and meal in the freezer or refrigerator to keep them from going rancid.

What do nut flours add to recipes?

Nut flours add moisture to baked goods, thanks to their relatively high proportion of oil compared to grain-based flours. “That can be really interesting for things like cakes and quick breads where you’re looking for softness and a denser crumb,” said Aran Goyoaga, author of three cookbooks, including “The Art of Gluten-Free Bread.”

Goyoaga cautioned that nut flours’ sticky density generally works less well in recipes for cookies, where crispness is often desirable. But when incorporated in modest amounts, such as the hazelnut flour found in traditional Linzer cookies, they deliver a dose of nuttiness without negatively impacting the texture.

“I also like to use a little nut flour for press-in and crumb-based pie crusts,” Goyoaga said.

Beyond batter and dough, nut flours can lend delicate flavor and nubby texture to a horchata, help thicken the sauce for roasted vegetables, and make a creamy and decadent frangipane layer in croissants aux amandes.

For home cooks looking to up their baked goods’ nutrient density, mixing in nut flour provides protein, heart-healthy fats and fiber to the dry mixture. Nut flour alone might not transform a decadent Hazelnut Chiffon Cake With Nutella Ganache into a superfood, but it does increase its overall nutritional profile.

Where should you not use nut flours?

Nuts contain plenty of protein but not the binding or structural proteins that you find in flours you’d use for most baking, whether all-purpose flour, bread flour or gluten-free flour blends formulated for bread and other purposes. “I don’t use a lot of nut flours in yeasted or sourdough breads,” Goyoaga told me. “With bread, you want a chewy bite, crisp crusts and elasticity, and nut flours don’t do any of that well.” If you want to impart a nutty flavor to your yeasted or sourdough breads, Goyoaga recommends whisking a little chestnut flour into the dry mix, since it’s high in carbohydrates that help the yeast or bacteria bloom.

Can you substitute nut flour for all-purpose flour?

Some recipes were developed to play to nut flours’ strengths. But in most cases, if a recipe was developed with all-purpose flour, swapping in all nut flour will yield disappointing results. “If a recipe calls for 1 cup of all-purpose flour that weighs about 125 grams, and you substitute 1 cup of almond flour, which weighs about 100 grams, you won’t have enough dry ingredients to absorb the moisture or provide adequate structure,” Goyoaga said. “Your cake will likely sink in the middle while it bakes, or taste too oily or heavy.” Another option: recipes that combine gluten-free flour blends with nut flour for the best of both worlds, such these Bakewell Tart Bars.

Goyoaga recommends sticking to basic substitution ratios. “For quick breads and moist cakes, you can generally substitute up to 50 percent nut flour successfully,” she said. For cookies that stay crispy when baked, she suggests substituting no more than 25 percent of the overall flour with nut flour.

Can you make your own nut flours?

Store-bought nut flours are convenient, and commercial mills yield nut flours with a fine texture and even consistency that can be challenging to replicate at home. But buying whole nuts and grinding them in a food processor or high-powered blender is a great way to control the flour’s freshness. It can be more cost-effective, especially if you buy nuts in bulk and store them in the freezer until needed. Grinding at home also lets you make just the right amount of nut flour required for a particular recipe.

“One challenge with grinding nuts at home is that the concentration of oils in nuts can make them quickly turn into paste, rather than flour,” Goyoaga said. She recommended adding a tablespoon of all-purpose or brown rice flour to the food processor along with the nuts to absorb oils expelled during the grinding process.

What if I am allergic to nuts?

Bakers looking to add a sweet, nutty flavor to their recipes without the nuts should consider tiger nut flour. “It acts like nut flour but it is botanically a tuber, which means people with allergies can tolerate it,” Goyoaga said. “It’s great for baking, not excessively oily and full of fiber.” Tiger nut flour is not widely available in stores but can be sourced online and used to bake up a batch of Five-Spice Cranberry Thumbprint Cookies.

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Bakewell Tart Bars

For the crust

Scant 1 cup (160 grams) all-purpose gluten-free flour blend

Scant 1 cup (100 grams) almond meal/flour

½ cup (110 grams) granulated sugar

1 teaspoon fine sea salt

10 tablespoons (1¼ sticks/142 grams) cold unsalted butter, cut into ½-inch cubes

1 tablespoon cold milk

For the filling

8 tablespoons (1 stick/113 grams) unsalted butter, at room temperature

½ cup (110 grams) granulated sugar

½ teaspoon almond extract or vanilla extract (optional)

Pinch fine sea salt

2 large eggs, at room temperature

1¼ cups (140 grams) almond meal/flour

¾ cup raspberry jam or strawberry jam

3 tablespoons sliced almonds (optional)

Make the crust: Press two long pieces of aluminum foil into a 9-inch square pan perpendicular to each other to create a sling, leaving several inches of overhang so you can use it to pull the bars out of the pan later. Generously grease the foil with cooking oil spray. (This will help release the bars after they are baked in case any jam bubbles out.)

Whisk together the gluten-free flour, almond meal, sugar and salt in a large mixing bowl. Work the cold, diced butter into the flour mixture between your fingers until the mixture has the consistency of sand. Add the milk and mix with a fork until a wet, crumbly dough is formed. Press the crust mixture into the bottom and up the sides of the pan, ½- to ¾-inch high. Transfer the pan to the freezer for 30 minutes to chill.

While the pan is in the freezer, preheat the oven to 350°F with a rack in the middle position.

Line the chilled crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, until the crust is just starting to dry (it will still look fairly pale). Remove from the oven, and remove the weights and parchment. Return to the oven and continue baking until the crust develops a light golden hue in a few spots, 8 to 10 minutes. (It will still be on the pale side.) Transfer the pan to a wire rack.

Make the filling: In the bowl of a stand mixer or with a handheld mixer and a large bowl, combine the butter, sugar, almond extract (if using) and salt on medium speed until fluffy and lighter in color, 2 to 4 minutes. Scrape down the sides of the bowl, and add the eggs, one at a time, beating well after each addition. Scrape down the bowl again, reduce the speed to medium-low and add the almond meal, beating until just combined.

Spread the jam evenly in the warm tart crust. Drop the almond filling mixture in small scoops over the jam, then spread carefully and evenly over the jam. Scatter the sliced almonds over the top, if using. Bake the tart (still at 350°F) until the filling is puffed and browned and the center springs back when lightly pressed, 35 to 40 minutes. Let cool completely on a wire rack. Remove the slab using the foil sling and cut into 12 to 16 bars.

12 to 16 servings (makes one 9-inch slab)

Substitutions: For gluten-free blend, use all-purpose flour. For raspberry or strawberry jam, use apricot, blueberry, cherry or whatever you have on hand. Don’t like sliced almonds? Leave them off, or swap in your choice of nut.

Nutrition (based on 16 servings) | Calories: 320; Total Fat: 21 g; Saturated Fat: 9 g; Cholesterol: 57 mg; Sodium: 145 mg; Carbohydrates: 30 g; Dietary Fiber: 2 g; Sugars: 19 g; Protein: 4 g.

— Adapted from “The Official Downton Abbey Afternoon Tea Cookbook.” Weldon Owen, 2020. Crust recipe by Aran Goyoaga posted at kingarthurflour.com.