By Anastasia Yandulskaya, PhD Candidate in Cell and Molecular Biology
Ah, the joy of eating a freshly baked loaf of bread! With its chewy crust and pillowy crumb, slathered with butter and sprinkled with coarse salt, a slice of bread is a delicious treat.
But what of those who cannot stomach gluten-laden wheat bread? As gluten is integral to good bread structure, people who are intolerant to gluten often find themselves gnawing on dense and crumbly slabs of gluten-free bread. To help put tasty bread on the table for everyone, a team of scientists in Spain set out to investigate how to make gluten-free bread more pleasant to eat.
No gluten? No problem!
Rice flour naturally lacks gluten, which makes it a handy ingredient in gluten-free baking. To create gluten-free bread dough, the scientists mixed rice flour with cornstarch and added other ingredients like salt, yeast, and a plant-derived compound called hypromellose to improve texture. Afterwards, they manipulated two important aspects of bread-baking: hydration and fermentation.
Hydration refers to the amount of water in the dough. The researchers baked higher-hydration breads, with equal parts water and rice flour-starch blend, and lower-hydration breads, which had less water.
Fermentation refers to the amount of time that bread dough is allowed to sit in a warm spot and develop yeast. As yeast cells multiply in the dough, they release carbon dioxide, making the bread expand in the oven. The researchers let their rice breads ferment for either 30 or 75 minutes.
By the end of their baking adventure, the scientists produced four types of gluten-free rice breads: high-hydrated and short-fermented, high-hydrated and long-fermented, lower-hydrated and short-fermented, and lower-hydrated and long-fermented. I can only imagine how amazing the lab must have smelled from all that freshly baked bread!
Biting off more than you can chew?
The researchers then recruited volunteers to taste-test the assortment of baked goods. Unfortunately, the volunteers didn’t get to eat the bread. Instead, they took a bite, chewed on it, and then spit it out in a cup. Afterwards, they wrote down their thoughts on the breads’ taste and texture.
The research team studied the chewed-up bread bits, measuring how crumbly they were and how much saliva was needed to moisten the bread in the mouth.
The rice breads with high hydration (equal parts water and rice flour/starch mix) required less saliva to moisten the bit-off pieces, likely reducing the volunteers’ desire to take a drink of water after taking a bite. As gluten-free bread is notoriously dry, adding more water to the dough could help solve this problem.
Long-fermented breads were easier to chew and boasted a soft, open crumb with plenty of aeration, or air pockets that give bread that pillowy feel. The taste-testers also noted that long-fermented breads didn’t feel as sticky in the mouth.
The tradeoff of aeration? Crumbliness. The taste-testers thought that the rice breads made lots of crumbs in the mouth. Indeed, as with the absence of the structural support provided by gluten, bread crumbles under pressure. It seems like it’s best to eat rice bread sandwiches over a big plate to avoid having to sweep the floor clean of crumbs.
What’s the big picture?
Rice flour and other gluten-free flours are very different ingredients from wheat, and the texture and taste of gluten-free brioche will differ from the one at your local French bakery. But that doesn’t mean that rice flour treats can’t be delicious!
Other ingredients like xantham gum help improve the structure of gluten-free baked goods. Tips and tricks on the baking technique are also important – such as that, as scientists have shown, the amount of water in the dough and fermentation time make a difference in gluten-free bread baking.
So if you want to surprise your gluten-intolerant friend with some homemade rice bread, consider adding more water to the dough and letting it rise for longer.
Reference: Puerta, Patricia, et al. “Modifying gluten-free bread’s structure using different baking conditions: Impact on oral processing and texture perception.” LWT 140 (2021): 110718.
Peer-edited by Raj Trikha, M.S.
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