Sunday, June 3, 2007

Apple #245: Pistachios

Regular readers of the Daily Apple have probably noticed that I usually have a new entry posted on Sunday evening. This is because I know what it is like to have a job that you loathe, that sucks your soul each day a little more, and therefore what a balm it can be -- however temporary -- to have something entertaining, humane, diverting to look at on a Monday when you've just said good-bye to your weekend and the long week is starting up again. That is no longer true for me, but it once was. So I sympathize.

Last night, I did not complete my usual mission. I started this entry on Sunday (hence the Sunday time stamp) but could not finish it. We had an enormous thunderstorm, and after it passed and turned into lightly trickling rain, my cable went out. For two and a half hours. Then it was bedtime. So this entry is a day late. To those of you who rely to any degree on reading this on your Mondays, I apologize. But at least you have something new to read today, yes?

Now, on to the entry itself.

So, the last time I went to the grocery store, I bought some pistachios.

You can buy these roasted pistachios for about $6.75 a pound from Nuts Online.
(Photo from Nuts Online)

I've been eating them in my lunches at work and as a snack in the evenings. I have to eat them with two hands, to pinch open the shells and sometimes pick off that brown coating over the green nutmeat. Because it takes two hands, I therefore concentrate on what I'm doing, which led to me think about the nuts I was eating.

It struck me that these nuts are unique in many ways:

  • The shells are split open already. We don't eat any other nuts (that I know of) that are already open. I think if I came across a walnut or an almond that was split open as much as most pistachios are, I'd be inclined to distrust it. But if the shell of a pistachio is mostly open, then I think, mm yum.
  • The nuts are green. Again, I would normally associate the green color with unripeness. Not so with pistachios.
  • They're salted in a different way than, say, peanuts are salted. The salt on peanuts seems to be more granular, but the salt on pistachios is more of an all-over coating, or maybe a dusting. I'd like to know how they get that salt on there.
  • Used to be, pistachios were almost always dyed red. Where did that idea come from? Why red?

You see? Many observations, many questions.

  • If you get a pistachio with the shell unsplit, it means the nut is not ripe. Shocking, yes, but true. Somehow, somebody must have gotten this fact across to me because I do regard split pistachios as looking very good -- besides the fact that the unsplit ones can be a pain to open.
  • The nut -- technically "the kernel" -- expands as it ripens until it splits the shell. The California Pistachio Commission recommends discarding unsplit pistachios because that means they are unripe. But then, the CPC would have an interest in you throwing away your pistachios, wouldn't they?

Those closed-up ones really aren't as good as the already open ones.
(Photo found at the Foodgoat blog)

  • The green in the pistachio kernel comes from chlorophyll, the same thing that makes plant leaves green. Why the kernels are green as opposed to brown, which is true of most nuts, I don't know. I guess we'll have to ask the pistachio trees, and they're not talking.
  • Growers prefer kernels that are very green as opposed to yellow-green. Probably the yellow ones don't look as ripe.

Pistachios sans shells, which appear to have been dyed red.
They look good to me full-out naked like this, too.
(Photo sourced from Feed Me I'm Hungry's entry on 3 dishes to make using pistachios)

  • Before 1976, pistachios were not grown in the US but were imported from the Middle East (mainly Iran, Turkey, and Syria). Companies that harvested the nuts there used "antiquated harvesting methods."
  • It is true that if the nuts are picked but then are not processed for 12 to 24 hours, the shells get stained and spotted. So it's possible that those pre-1976 nuts were stained because the producers took a little too long to get to the roasting.
  • In any case, the US importers decided to dye the pistachios to hide the evidence of "antiquated harvesting." They decided that red was the right color, since it would make pistachios more eye-catching compared to other nuts. So that's how they got turned red.
  • Some pistachio-eaters are still partial to the red color, so some pistachios grown in the US are still dyed red using vegetable dyes.

Red pistachios, bagged & ready for you, for $3.50 from Walgreen's.
(Photo from Walgreen's)

  • I found a recipe for roasting and salting pistachios yourself, and I suspect it's the same method, on a smaller scale, by which pistachio processors get that really fine coating of salt on their nuts. Here's the recipe:
    • Add 2 to 3 ounces of salt to 1/2 cup of water (4 ounces).
    • Pour saltwater into a deep saucepan over high heat and stir to dissolve the salt.
    • Add 8 to 10 cups of pistachios and stir until all the water is evaporated and the salt remains on the nuts.
    • Transfer the salted nuts to a cookie sheet and roast in a preheated 250 degree F oven.
    • Roast 1 1/2 to 1 3/4 hours, stirring about every 30 minutes.

These pistachios were grown and are being processed in Iran, the nut's homeland, so to speak.
(Photo from Dorchin Co)

  • Some research was released lately that says eating pistachios helps reduce stress. As with all these medical studies involving food, however, that does not mean you can go out and shovel truckloads of pistachios down your throat and expect to be stress-free.
  • The research showed that people who ate a small to moderate amount of pistachios (1.5 ounces per day, or about a handful) showed signs of the lowest amount of stress, where people who ate more pistachios (3 ounces per day, or about two handfuls) were only slightly less stressed out than the people who ate none.
  • So as always, beware those articles with the headlines that proclaim that this or that food will make you happy / skinny / avoid heart disease / sexy / stress-free / taller / fill in the blank.

  • Keep pistachios stored in an airtight container, or they will get soft (as I myself discovered).
  • You can freeze the nuts, too, and keep them that way for months.


  • Pistachios are related to both the cashew and the mango.
  • Pistachios are not actually nuts but are drupes, which are fruits with a single seed. In other words, stone fruit, like peaches, apricots, plums, cherries -- and mangos.
  • A pistachio tree does not produce nuts until it is at least five years old. It reaches its full nut-making capabilities somewhere between age seven and age ten.

A young pistachio tree in Georgia
(Photo from the University of Georgia)

  • Many pistachio trees in the Middle East are hundreds of years old. One pistachio tree in Iran is still producing at a ripe 700 years old. Another in the Ukraine's Nikitsky Botanical Garden is 1,000 years old, but I don't know whether it still makes nuts. Here's a photo of a gnarly 1,500 year old pistachio tree in Greece.
  • Only the female trees produce pistachios. The male trees produce the necessary pollen.
  • A new pistachio tree, about 3 to 4 feet tall, will set you back about $28.50.
  • It took US growers 47 years to figure out how to raise pistachios as a crop. Seeds were first brought from Iran in 1929, and people planted and experimented for years before they got the trees to produce like their Iranian ancestors.

Pistachios on the tree
(Photo from the California Pistachio Commission)

  • You can shake, knock, or pick ripe nuts from the tree. The California Rare Fruit Growers association says, "A single shaking will bring down the bulk of the matured nuts." I like the idea of standing under a pistachio tree and shaking it so that all sorts of nuts come raining down.

California Pistachio Commission FAQs
California Rare Fruit Growers, Inc., Pistachio, 1997
"Why Are Some Pistachios Red?"
Popular Science, July 2002
"Pistachios Lower Cholesterol, Provide Antioxidants," Social Science Research Institute News, Penn State, May 14, 2007
Eagle Ranch Pistachios, Pistachio Tree Information


  1. Very interesting article... I never seen red pistachios, but now when I know I would never buy them :)

    Have a nice day, Margot

  2. Thanks, Margot! I think you're probably not the only person who is turned off by the red dye, and that's probably why you don't see red pistachios as often anymore.

  3. since a few years back when the pistashos had a wonderful coating of granular salt....I do not buy the salt washed version any longer. A larger number of people choose to avoid the salt sprayed nuts, knowing there is a huge loss of flavor....dave, michigan

  4. Very informative post. keep up the good job and very nice pictures to go along with, but one seems to be missing.

  5. Thanks for your great information, the contents are quiet interesting.
    Thank you again for your flawless service, and I look forward to working with you in the future.


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