Everyone loves chocolate, but few realize its rich cultural heritage. For example, cocoa beans were once so valuable, they were actually used as currency.

The first people to harvest the fruit of the cacao tree were the ancient Aztec and Mayan cultures over 2000 years ago. Chocolate was an integral part of their society, often appearing in ancient artwork as a pot overflowing with brown liquid.

Chocolate at this time was strictly a drink. It would not be consumed in solid form for centuries. Chocolate was often used to commemorate celebrations, much the same way we use champagne today.

It is important to realize these early cultures did not add sugar to their chocolate drink. It would have tasted very bitter, like mixing cocoa powder and water. These ancient cultures often added hot chilies to their chocolate drink, and sometimes even dyed it red to make it look like blood. Not very appetizing by today’s standards!

Chocolate was taken to Europe after Spanish explorers conquered Central America in the 1500s. The Spanish added sugar to the drink, making it taste more like the hot chocolate we know today.

Instead of spreading north through Native American cultures, chocolate actually traveled across the ocean with the Spanish, where it spread throughout Europe as an exotic new drink. The colonists who settled the New World would have known about chocolate from back home, not through contact with native North American peoples.

Chocolate was quite expensive in Europe, because of high shipping costs, so ordinary citizens did not have access to it. The French believed chocolate was an aphrodisiac and slapped heavy taxes on it. Only the elite of society – the nobility and royalty – could afford chocolate.

The cacao tree is extremely sensitive and can only be grown 20 degrees north and south of the equator. It can only thrive in climates that maintain a temperature between 60 and 80 degrees Fahrenheit. It takes seven to ten years to fully mature and begin bearing fruit.

The tree is rather odd looking, because the cacao pods actually grow from the trunk of the tree. The pods are harvested by hand twice a year. Each tree grows 20-30 pods a year, and each pod contains 30-40 cocoa beans.

This article is based on the author's research for her own exhibition "Sweet Stuff: The Story of Chocolate."

Is Chocolate: The Exhibition coming to a city near you?

The exhibit was developed by The Field Museum in Chicago. Here is its tour schedule through 2012:

January 29 - May 22, 2011
Anniston Museum of Natural History
Anniston, AL

June 17 - September 11, 2011
Muzeo
Anaheim, CA

October 8 - January 8, 2012
AVAILABLE

2012 January 28 - April 28, 2012
Royal Botanical Gardens
Ontario, Canada

May 19 - September 9, 2012
Turtle Bay Exploratorium
Redding, CA