The shell of the pistachio is naturally a beige color, but it may be dyed red or green in commercial pistachios. Originally, dye was applied to hide stains on the shells caused when the nuts were picked by hand.[51] In the 21st century, most pistachios are harvested by machine and the shells remain unstained.[51]
Wikipedia
Well now I’m wondering what those stains were. Did they dye them red because the people picking them had their hands bleeding? We were all just ingesting small amounts of laborer’s blood?
Yes, but as technique improved, there was less blood introduced on average and the pistachios would not be evenly coloured. To preserve the impression of quality, the farms then adopted the policy of wringing the worst performing worker of each batch of their blood to cover the batch in red homogeneously. This motivated improved performance batch on batch (less blood) and eventually, two workers had to be wrung, and at some point the remaining workers got so good that no blood was introduced and a drastic policy change had to take place.
The shell of the pistachio is naturally a beige color, but it may be dyed red or green in commercial pistachios. Originally, dye was applied to hide stains on the shells caused when the nuts were picked by hand.[51] In the 21st century, most pistachios are harvested by machine and the shells remain unstained.[51] Wikipedia
I found this great place that dyes it with garlic
Well now I’m wondering what those stains were. Did they dye them red because the people picking them had their hands bleeding? We were all just ingesting small amounts of laborer’s blood?
Yes, but as technique improved, there was less blood introduced on average and the pistachios would not be evenly coloured. To preserve the impression of quality, the farms then adopted the policy of wringing the worst performing worker of each batch of their blood to cover the batch in red homogeneously. This motivated improved performance batch on batch (less blood) and eventually, two workers had to be wrung, and at some point the remaining workers got so good that no blood was introduced and a drastic policy change had to take place.
That or automation.
They really should do an episode or How It’s Made on this. Super fascinating!
Another commenter said it was the oil on people’s hands
Blood oxidizes to a dark brown/black pretty quickly so a red dye wouldn’t really hide it.