Why is my pistachio sour?

Online Answer
YSK that many of those sour/bitter pistachios you come across are actually filled with moth's larvae which is impossible to remove from the inside, since pistachios are sold with the shell.
Related Questions 📌
Actually, it is very common that pistachios have worms in them. The more research I did on this, I realized that the worm that is commonly found in pistachios are called Navel OrangeWorms. Navel OrangeWorms can be found in almonds and in pistachios.
The most obvious reason behind the high price of pistachios is, it is very difficult to cultivate. A pistachio tree takes about five years from the day it is planted before it starts producing fruits..
Peak Production Is Only Every Other Year Pistachios are "alternate bearing", which means one year the tree has full production, followed by a year of lower production, when it stores nutrition for the upcoming year.