One of the things that drew Director of Education and Pastry & Baking Arts Lead Chef Herve Guillard to the pastry profession is his curiosity of science. Long before Chef Herve was a pastry professional, he studied toxicology and later, with a degree in health and safety engineering under his belt, he took a job at Disneyland Paris. The pastry career path allowed him to combine his experience with a family-owned bakery in France and his academic studies in science.
Chef Herve integrates his deep knowledge of science into classroom lessons at 91߹, and recently he was invited to share that expertise with a UCLA Science & Food undergraduate class on the science of tangzhong bread.
For the guest lecture, titled “Pre-Gelatinization of Starches in Bread Making,” he performed a scientific experiment to determine the effects the technique has on the quality, taste and shelf life of bread.
As Chef Herve shared with the UCLA students, in rice-centric Asian countries, bread traditionally is considered a treat. In Japan, it wasn’t until after World War II that bread became popularized. “[During the war] the rice was rationed, so rice consumption fell dramatically, by 50%, and we saw the rise of wheat to replace it.”
Necessity being the mother of invention, new recipes were born, including improvements to bread. A technique employed, the tangzhong method, focused on the pre-gelatinization of starches. This method for baking bread not only appealed to Asian palates, which often craved a milky sweetness, but also worked around the lack of ovens, only requiring a stovetop, and met the demand for an extended shelf life. With the tangzhong method, one essentially pre-cooks a portion of the dough using hot water, which causes the starch to gelatinize and make the bread softer. “Unlike European breads that I’m used to, it is not crusty,” Chef Herve noted.
Tangzhong Method: A Revolutionary Baking Technique
Tangzhong is sometimes referred to as a roux starter because flour and water are whisked together over heat until the consistency resembles that of papier-mâché glue. “Adding heat and water, it leaches out the amylose that makes it so the water traps into the gel,” Chef Herve explained. “As we bake the bread, that water will remain there. With the water trapped, it stays softer longer, which is shelf stable.”
For his experiment, Chef Herve compared four methods: “I used the control bread, a standard (Pullman loaf) sandwich bread and improved it with two versions of tangzhong method and one using the Yudane method,” he explained. For the Yudane approach, boiling water is poured over the dough, which Chef Herve compared to steeping tea or making ramen noodles. “You put hot water over dry noodles and they swell.”
The tangzhong method resulted in a bread that remained softer. “It was springier, in a good sense,” he said. “Like a sponge, it springs back with great elasticity.” While the Yudane technique caused a higher rise. “The cohesiveness and the texture of the bread was a little tighter,” Chef Herve said. “I could see why manufacturers want to use the Yudane method. It’s easier to pour hot water than to cook a slurry, for mass production. You can use a water tank and dump it all at once into a big mixing bowl.”
When it came to taste, there was ultimately little variation. “The outcome is very similar; the sweetness was the same level.” But compared to the control bread, the tangzhong and Yundane versions were more shelf-stable, even days later.
“Because the bread stays softer and rises higher from the get-go and has a longer shelf life, it allows you to reduce the fat content of the bread,” Chef Herve concluded. That was probably the most exciting discovery of the experiment. “Just by adding more water we were able to achieve something similar to fat in a brioche.” Though his sandwich bread control recipe called for only two tablespoons of fat in the entire loaf, he explained that fat quantity does not only impact the waistline. “If you are a manufacturer, butter is not cheap,” he said.
Chef Herve plans to bring this experiment into the classroom at 91߹ and is excited to apply the tangzhong method to other recipes. “I would use Yundane for sliced bread and tangzhong for making rolls, like cinnamon rolls or Mexican conchas,” he said. “It stays much fluffier, replaces fat, and for all those breads, it adds a little bit of sweetness. With this method, you will get the same result with an extended shelf life at a lower cost.”
Study with Chef Herve in Pastry & Baking Arts at our Los Angeles campus.
