Pistachio Varieties

Pistachios come in numerous varieties. Most have been developed by farmers, including small-scale variations in specific regions like Iran. Every so often, one of these small, regional variations will get picked up on a larger scale and is produced by other farmers. Eventually, some can become commercial varieties. When it comes to Iranian pistachios, there are two primary commercial varieties, categorized by shape: long or round. If the ratio of the length of the pistachio to its diameter at the thickest point is greater than 1.5, then it is called long – otherwise, it’s called round. The original, wild pistachios were of the long type. Eventually, around 70 years ago, the round variety was developed by a farmer from Rafsanjan whose name was Mr. Ohadi. The many commercial varieties tend to come in and out of fashion, with some no longer in production.

Nut Morphology and maturation

Pistachios, like grapes, grow in clusters. They are classified similarly to almonds, peaches, apricots, plums, and cherries, as drupes. This means that they are comprised of three parts: a hull, a shell, and a seed. The pistachio is the nut or seed, as is an almond; in the case of peaches and apricots, the seed is discarded and instead the hull is eaten. As pistachios age, the hull and shell begin to separate and shell splits. Not all pistachios are like this, and not all nuts will necessarily split – this depends on the variety, irrigation, climate, and weather conditions. Early splitting is also possible in all varieties, when the shell will split before separating from the hull. This is dangerous, as the unripe hull provides access to the kernel for undesirable aflatoxins like Aspergillus Flavus. An early, quick harvest is the best way to avoid this, as early splitters need time before such toxins can set in.