Our Delicious Story: The 70s: It's 1976 and two childhood friends open their first ice cream parlor as a Double Rainbow lights up the San Francisco sky. The 80s: A little recognition never hurts. Double Rainbow gets voted best ice cream in America. The 90s: Some local love. The mayor of San Francisco proclaims Double Rainbow as the city's official ice cream. Til Infinity: We remain a family owned business and continue our tradition of making award winning ice cream, using only the best ingredients. Thank you for being a part of our story. No rBST. Our cows are not treated with rBST. The FDA has said that no significant difference has been shown between milk derived from rBST-treated and non rBST-treated cows. doublerainbow.com. (at)doublerainbowicecream.