Pistachios: Green Kernels, Split Shells and How to Choose Them

Pistachios are the seeds of a small tree native to Central and Western Asia, and they have been eaten for thousands of years. Today Iran, the United States and Turkey are among the largest producers. The kernel is green-to-purple under a thin skin, wrapped in a hard shell that splits open as it ripens.

What makes pistachios special

Their flavour is rounded, sweet and a little earthy, with a green, almost resinous note. They are one of the few nuts with a naturally green colour, which makes them popular for decorating desserts. The colour comes from chlorophyll and other pigments, and deeper green nuts are usually fresher.

Buying them

In-shell pistachios are sold roasted and salted or raw. A split shell is normal and shows a nut that has matured, and the opening is how you crack it. Shelled kernels are convenient for cooking, but cost more. Choose unsalted ones for baking and sauces so you can control the seasoning. Check for a fresh smell and avoid any that are shrivelled or look dark and dry.

Ways to cook with them

In Turkish and Middle Eastern sweets, they fill baklava and sit on top of halva and Turkish delight. In Italy, pistachio paste makes gelato, cakes and mortadella. In savoury cooking, crushed pistachios make a crisp crust for fish or chicken, and a topping for rice and couscous. Sprinkle chopped pistachios on salad, yoghurt and roasted vegetables. In Persian cooking they appear in rice dishes with saffron and barberries, and in sweet cardamom pastries.

Preparing them

To blanch and peel shelled pistachios for the greenest colour, boil them for a minute, drain, then rub the skins off in a towel. For pesto and cakes, lightly toast the nuts at a low oven setting for about 8 minutes. Grind them with sugar or a little flour to avoid turning them into butter.

Pistachios supply protein, fibre, unsaturated fats, vitamin B6 and minerals such as potassium and phosphorus. They also contain lutein, a plant pigment. As with all nuts, they are calorie dense, but cracking in-shell nuts slows you down and gives you a visible pile of shells as a gentle portion cue.

Storage

Store shelled nuts in an airtight container in the fridge for a few months, or in the freezer for longer. In-shell ones last several months in a cool, dry place. Keep them away from damp, since moisture encourages mould.

Cautions

Pistachios are tree nut allergens, and people allergic to cashews often react to pistachios as well because the two are related. Food safety matters, too: discard nuts that smell musty or look mouldy, because some moulds produce aflatoxins, which are harmful. Salted in-shell pistachios can be high in sodium, so read the labels if you watch salt. Store opened bags well and never eat nuts that taste bitter or off.

This article is general information, not medical advice.