Why saffron is the world's most expensive spice

Harvesting saffron requires a lot of physical labor to get the flowers from the field to final packaging. The harvesting process plus its distinct flavor, smell, and color make it the most expensive spice in the world. It's used in kitchens across the world, as a fabric and skin dye, and may soon be used more widely for medicinal purposes. Following is a transcript of the video.

Narrator: This is saffron and just one pound of it can cost you $5,000. It is easily the world's most expensive spice. The next most expensive spice? Vanilla, at about $600 a pound. So, what makes saffron so wildly expensive? For starters, saffron is a complicated spice to harvest.

Arash Ghalehgolabbehbahani: My name is Arash Ghalehgolabbehbahani. I am a postdoctoral research associate at University of Vermont. To harvest the saffron, you need a lot of hand works to pick up the flowers, separate - saffron is dehydrated or dry stigma. The stigma is the female part of flower. You have to separate that stigma, dry that. And for all of these procedures, you need hand works, laborers. I prefer to harvest the flowers by hand because I don't like to damage the other parts of the plants.

Narrator: Saffron comes from the saffron crocus flower. And each flower has three red stigmas - that's the saffron.

Ghalehgolabbehbahani: The yield of saffron is really low. You have to hire a lot of laborers to harvest 4 pounds of saffron per acre. That's nothing.

Narrator: Ultimately, you'll need to hand-pick 170,000 flowers to create just one pound of saffron. The purple flowers only bloom over a 6-week period from late September to early December. There's also a specific time of day to harvest them.

Ghalehgolabbehbahani: When we have a higher relative humidity in the air, it can affect the saffron quality. Also, sunlight can break the chemical structure in the saffron. So, we prefer to harvest the saffron early morning every day

Narrator: 90% of the world's saffron is grown in arid fields in Iran. But harvesting all of that saffron comes at a price.

Ghalehgolabbehbahani: Why Iran is the main producer of saffron? Because workers are available and they are cheap. In some parts, it's like slavery, their behavior with laborers. I hate that, I should say. Based on my experience, they usually, workers came to the farm in Iran around 5, 6 a.m. and they left around 4 p.m.

Narrator: Most saffron harvesters are women, getting paid a maximum of $5 a day. Saffron is not only grown in Iran. It's grown in Morocco, Spain, Italy, the Netherlands, Afghanistan, India, and even in the United States. Why the U.S.? Though many Americans have never eaten saffron, the US imported 25 tons of the stuff in 2013 and 46 tons in 2016.

Ghalehgolabbehbahani: I knew that saffron has a good resistance to the cold weather. If you cover Vermont state with a layer of plastic, you will have the same situation that we have in Iran.

Narrator: What's so great about saffron? Over centuries, it's proven useful in many situations. Saffron is most commonly used in cooking.

Ghalehgolabbehbahani: As an Iranian, every day we use saffron in our dishes. We cook with saffron a lot. So far I cannot find an alternative for the taste of saffron.

Narrator: It give dishes like paella its signature flavor and golden color. It's also used in broths, breads, and marinades. When saffron is broken down, it creates a yellow-gold dye.

Ghalehgolabbehbahani: Saffron contains some chemical components, which are really expensive like picrocrocin, crocin, and safranal. They are three main components or compounds which are responsible about the taste and color and smell of saffron. When we are talking about saffron quality, technically we're talking about these three chemical components. Saffron is inherently a valuable thing.

Narrator: Historically, people have tried passing turmeric, red marigold petals, and lily flower stigmas as saffron. But the flavor and dye is totally different. In large quantities, saffron can be a potent, happiness-inducing narcotic. And research suggests it may help reduce the symptoms for Alzheimer's disease, depression, and PMS. Who knew this little spice packed such a punch?