Another essential part of Chick-fil-A’s biscuits is their “secret” ingredient (it actually isn’t so secret if you’re a Southerner), which is self-rising White Lily brand flour. White Lily has been in business since 1883, according to the company’s website, and what sets the brand apart is that it uses 100% soft red winter wheat.
Southern Kitchen explains that the reason this particular flour is well suited for biscuits is that it is low in protein and gluten than all-purpose flour. Because biscuits are a type of quick bread, using an all-purpose flour can result in tough, dense results. White Lily has a protein content similar to pastry flour, providing softer results.
The website Healthy Happy Life tested the importance of flour in biscuit-making and found that using Chick-fil-A’s “secret” ingredient did in fact produce superior results. They experimented, making biscuit batches with White Lily’s self-rising flour and Bob’s Red Mill pastry flour. While the Bob’s flour resulted in a “nuttier” and perfectly fine result, the White Lily flour confirmed what Southern bakers have always said: White Lily produced a “spongy, fluffy, flaky, very tender biscuit.”