In the U.S., the Oreo variety of Blizzard is most popular. In China, the most popular is Green Tea. Their exact recipe is a closely-guarded trade secret, which they believe makes their 5% butterfat soft-serve "queen among dairy products," as Jack McCullough said.<ref name="/mentalfloss.com"/> | In the U.S., the Oreo variety of Blizzard is most popular. In China, the most popular is Green Tea. Their exact recipe is a closely-guarded trade secret, which they believe makes their 5% butterfat soft-serve "queen among dairy products," as Jack McCullough said.<ref name="/mentalfloss.com"/> |