Sour Grape is a cross of Sour Diesel and Granddaddy Purple, also known as Grand Daddy Purp or GDP — not to be confused with Sour Grapes from Apothecary Genetics, which is a cross of Sour Diesel and Grape Ape.

As its name indicates, Sour Grape is often described as having a fruity and sour aroma, leading to a sweet grape flavor when consumed.