Unfortunately for the pistachio lover we use walnuts instead of pistachio nuts. The flavoring used in the fudge, however, is a pistachio extract and is unmistakable.
The pistachio nut comes from a pistachio tree which loves cool winters and hot summers and dry locations. Its history is fascinating. Pistachio nuts were first recorded as being cracked in Asia around 7000 BC. In 1825 Charles Mason brought some over to the USA and the pistachio industry was born in California and the Southwest. It's a unique nut with a shell that is already somewhat split which makes it easier to roast and salt in the "nut" factory.