On this episode we’ll answer the question how do pistachios grow?
The pistachio, a member of the cashew family is related to the spice sumac and mangoes.
The pistachio or the green almond is also known as the happy nut in China or the smiling
nut in Iran.
Believed to have originated from central asia this only a guess as we don’t really know.
Mentioned in the bible the pistachio is one of the oldest flowering nut trees, only two
nut trees were mentioned in the bible which tells us humans have been eating them for
at least 9000 years.
Legend has it that pistachios grew among the hanging gardens of Babylon over 2700 years
ago, another legend, don’t worry we’ll get to real facts soon, is the Queen of Sheba
declared the pistachio as a food only for royalty to which she would take her entire
country’s harvest of pistachios for herself and her royal court.
Emperor Vitellius introduced Rome to the pistachio in the first century, this is confirmed by
mention of pistachios in a classical Roman cookbook of that time.
During the 17th century pistachio trees were called pitch trees in Ukraine as people would
consume the tree’s pitch or sap as a breath freshener.
Demand for this nut has skyrocketed since the late 1970s, it was introduced to the United
States in 1854 as a garden tree, hardier varieties were collected in 1904 but commercial production
didn’t begin until 1929.
The average pistachio tree produces around 50,000 or 110 lbs or 50 kg of nuts or technically
seeds every 2 years.
Pistachios are biennial bearing so their harvest is much heavier in alternate years.
They can live up to 300 years, they take 7 to 10 years to produce fruit but full production
of the tree happens doesn’t happen until they are around 15 - 20 years old.
The top consuming countries of pistachios are Turkey, United States, Iran, China, Germany,
Spain, Italy, South Korea, France and Syria.
There are 11 species of pistachio nut trees only Pistacia vera is produced commercially.
Pistachios are known for their high price tag in the grocery store, let’s get into
why that is.
3 main varieties of pistachios produced are the Sicilian Napoletana in Italy, Sirora in
Australia, and Kerman in the United States.
Pistachios are harvested in late summer from August to mid-September in California, which
produces 98% of America pistachios.
The kerman female plant is pollinated by the male Peters variety at a ratio of 1 male tree
for every 8 - 12 female trees.
Iran is the biggest producer of pistachios worldwide but Turkey, Afghanistan, Italy,
Syria all grow them as well as they have optimal climates to cultivate them.
Pistachios grow best in areas with cold winters and hot summers, the reason for this they
have a dormant cycle that needs to be activated.
A cool period just above freezing will do the trick and after the growing cycle is initiated
pistachios prefer over 100 degrees Fahrenheit or over 38 degrees Celcius to thrive.
They produce best in well-draining soil, are drought tolerant and thrive in areas that
aren’t humid.
The flowers are pollinated by wind, usually, a good April storm will get the job done.
Classified as fruit trees, pistachios need to be pruned like one for optimal nut production.
A couple of main branches are chosen to be the framework of the tree with everything
else pruned back.
This will promote side branching.
Naturally, they’ll want to sprawl but in a commercial setting these trees are pruned
to have upright horizontal branches which makes for easier harvests.
Commercially pistachios are grafted onto rootstock trees or a base tree that gives the pistachio
additional protection against disease.
Harvesting pistachios isn’t an easy task which stops many growers away from growing
them.
All the nuts need to be harvested and processed within a few weeks as they all ripen at once.
Depending on the size of the operation, the nuts may be collected by hand or by partial
machine assistance or completely done by machines.
Some of the fresh nuts will go to local markets for sale the rest will be processed so they
can be shipped worldwide.
Pistachios can be eaten fresh but their shelf life if not dried isn’t very good.
If they aren't processed properly the chemical aflatoxin produced can cause a cancerous mold
that can be fatal, so stay away from those shady black market pistachios.
Machine harvesting is done with large shaker machines, the trees need to be pruned at a
height that allows these machines to fit underneath.
One of these machines can shakedown 60 trees an hour or 1 a minute and will load up with
1300 lbs or 600 kg of nuts before having to drop them off for processing.
Once the nuts are harvested they are stored in a cold room just above freezing and pulled
out at a speed that feeds the processing machines adequately.
The first step of processing is the dehulling which rips the pistachio fruit off the nut.
That’s right there is a fruit wrapped around the pistachio making it a drupe or stone fruit.
This technically makes the pistachio a seed and not a nut.
The fruit is only edible to the birds where we can eat the nut.
Pistachios with a nut inside will sink to the bottom of the water which are removed
and either dried in the sun or added to a machine like this one that blows hot air vertically
as it continually moves them through an auger.
A good dry pistachio is key to make sure there is no fungal growth.
Once the nuts are dried they travel through this machine with blades and teeth that make
sure each nutshell is split.
This process does end up with some nuts that still have yet to split, these nuts will go
into this machine with gear like teeth.
Each tooth will pick up 1 nut and at the top a spring-loaded bolt will individually crack
each shell.
For pistachios that are shipped with no shell they are sorted through a machine that has
4 buckets.
Whole pistachios, large shell fragments, pistachios with smaller shell fragments and shell dust.
The shell dust is burned as a fuel source, but the smaller pieces with pistachios needs
to go through the machine again with a strong vacuum turned on which will suck the shell
pieces away from the nuts.
These machines are customized based on where or what types of pistachios they are working
with.
The Sicilian Napoletana pistachio only has a 20% split rate of the shell vs the Australia
Sirora variety has an 85% split rate.
The town of Bronte in Italy supports the production of pistachios as a community.
They have an annual pistachio festival that brings in people all around to enjoy their
bright green pistachios along with pistachios desserts and pistachio ice cream.
The food forest where all this footage comes from is an Australian organic pistachio producer
with 1000 trees.
As the demand for pistachios increases new growers of this nut like the food forest will
be needed in different places around the world, like Australia.
Pistachios sold in the United States up until 30 years ago were bright red, this was just
a marketing tactic to sell more nuts.
Nuts being shipped in were blotchy and unappealing to US consumers so they were dyed red to make
them more appetizing.
Offering more vitamins and nutrients as well as protein than most other nuts, the pistachio
is high in calcium, folate and riboflavin making it a great addition to ones diet.
Hopefully now you understand not only a lot more about the pistachio but why they are
so expensive to buy.
Let me know which food you want to see next on this series of how they grow and until
the next one have a good one.