Make Perfect Gluten-Free Sourdough With This Expert-Approved Flour Blend

For people living with celiac disease or gluten sensitivity, it can be a challenge finding the right foods that may be gluten-free. One of the big culprits in aggravating the painful abdominal reactions associated with eating gluten is bread, particularly breads made with wheat, rye, or barley flour. As gluten intolerance has increased, there are many gluten-free bread options and gluten-free flours to choose from. 

Sourdough bread isn't usually included in a gluten-free diet, but we asked Nathan Myhrvold, founder of Modernist Cuisine and co-author of "Modernist Bread at Home" about the flour blend he uses for baking gluten-free sourdough bread. "In gluten-free baking, the best results come from blending various flours and adding other agents to help the dough maintain an elastic structure while rising," Myhrvold told Tasting Table. "Our basic gluten-free flour blend, for example, has seven required ingredients, plus a few optional 'improvers.'" 

Myhrvold's gluten-free flour blend combines white rice flour, brown rice flour, cornstarch, tapioca starch, and glutinous rice flour. "Don't be put off by the word glutinous," Myhrvold explained, "because the flour doesn't contain any gluten. In the case of rice and rice flour, 'glutinous' simply refers to the stickiness of the rice." The glutinous rice is an important component in his flour mix because when it's hydrated in the dough and baked, it mimics gluten's signature chewiness in regular bread. However, glutinous rice has a strong flavor that wouldn't make an appetizing loaf on its own, and so it's best to mix it with other flours.

Gluten-free bread can be denser and more compact than wheat-based bread with a tighter crumb and a noticeably lesser rise. However, two ingredients — the "improvers" Myhrvold referred to — solve those problems. The thickener xanthan gum is an important addition to Myhrvold's master recipe. Made from fermented sugar, xanthan gum absorbs water and adds viscosity to the dough, "helping [to] evenly disperse and suspend the starch particles in the crumb ... partially substituting for the structure that gluten would normally provide." Nonfat-milk powder is another beneficial ingredient as it naturally sweetens and adds lactose, which allows the loaf to brown from the Maillard reaction during baking. 

An optional ingredient — although Myhrvold highly recommends adding it into the flour mix — is transglutaminase (again, there's no gluten), an enzyme that is often used for binding small pieces of meat together. It works the same way in binding the proteins in gluten-free flours, and as Myhrvold told us, "the end result is a chewiness quite close to the texture of a standard bread." 

Many of his gluten-free recipes have nut milk, and some store-bought almond milk brands are fine, but at Modernist Cuisine, they make their own, which you can too, by adapting this almond milk recipe. Admittedly, gathering all the necessary ingredients for Myhrvold's gluten-free flour blend is a little time-consuming. But as Myhrvold suggests, "it's relatively easy to make a large batch of blended flour in advance to have plenty of it on hand (you can also freeze it in batch-sized portions)."