Professional bakers dip raw soft pretzels in a lye (sodium hydroxide) solution just before baking. What can the home cook use instead?
Professional bakers dip raw soft pretzels in a lye (sodium hydroxide) solution just before baking to promote rapid browning and give the twists their distinctive slightly alkaline flavor, chewy texture, and dark brown color. Since lye is extremely corrosive, requiring the use of goggles and gloves, pretzel recipes for home cooks typically call for a far weaker and safer base: baking soda (sodium bicarbonate). Unfortunately, it’s too mild to be very effective; pretzel dough treated with a baking soda solution more closely resembles breadsticks in color, taste, and texture. Here’s a better way: Transform baking soda into sodium carbonate—a more alkaline substance—by spreading 1 cup of baking soda on a baking sheet and baking it in a 250-degree oven for two hours. Baking dehydrates the soda to form sodium carbonate and carbon dioxide, raising its pH from about 8 to about 11. (Lye has a pH of 13 to 14.) When we immersed our pretzels in a solution of 2/3 cup of baked baking soda dissolved in 2 cups of water, rinsed them, and baked them, the results were dramatically improved. The twists boasted characteristic pretzel flavor along with crisp, deep-brown crusts and chewy centers.