ANCHOR: [STEAM WHISTLE] That’s the sound of a distinctly Mexican invention. As you can hear, it has fire in its belly and it whistles to blow off steam. It cooks, transports, and advertises its product…all at the same time. Reporter Shannon Young takes a closer look.
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El Llano park in Oaxaca City is just one of the places in Mexico where you’re likely to hear this…
[DISTANT WHISTLE IN PARK]
That’s the sound of steam-cooked plantains and yams…well, the sound of the cart they travel in. The cart itself is an icon of street vendor ingenuity. Its owner, Cesar Perez, explains.
CESAR PEREZ (voiceover): “This cart works with steam. I’m gonna make the sound for you. This sound is to let people know that the yam and plantain vendor is on the way. (STEAM WHISTLE sound)
The whistle works in the same way as an ice cream truck’s jingle. The sound projects for a couple of blocks, giving customers time to collect spare change and head outside by the time the vendor passes by.
[PARK TONE]
Local people call this invention a “camotero cart,” after the Spanish word “camote,” or “yam”. The cart resembles a rustic locomotive. It has a metal barrel that lies on its side, with a hole cut on the outer end. That’s where Perez feeds the wood that fuels the fire. The plantains and yams rest in a drawer situated over the flames. The smoke escapes through a sheet metal stovepipe on top.
The fire just keeps the food warm. Perez says the actual cooking process occurs before he hits the street.
CESAR PEREZ (voiceover): “You have to let the food cook to a certain point. Because if it only cooks a little bit, it tastes nasty. So it needs 2 hours of cooking before I leave home in order for it to be done.”
The end result is yams and bananas with a soft texture and smoky baked flavor that’s not easy to duplicate at home.
Meanwhile, every so often, water from an upside-down soda bottle releases steam into the cart’s cooking chamber. That keeps the food from drying out. The steam also creates the distinctive whistle sound when it escapes from the metal barrel through a special tube.
CESAR PEREZ (voiceover): “When the water falls on the hot part of the tube, it’s expelled at fairly high pressure which is what produces the little noise.”
The whistle on Perez’s home made cart has a pitch that’s a bit lower than others – something he did on purpose.
CESAR PEREZ (voiceover): “It’s different because each person has their own sound. That way they know it’s Mr. Cesar’s cart, of Mr. Julio’s or Gilberto’s – they know how to distinguish the sounds sometimes.”
The sound of the steam whistle is something that’s ingrained in the memory of Bernardo Sanchez, a young man who walks up to purchase one of Perez’s plantains.
BERNARDO SANCHEZ (voiceover): “Ever since I was little, I remember buying plantains from the cart that passed by my house. Now it’s a matter of tradition. Every time we hear this type of whistle, we know that they’re the baked plantains.”
The carts are also powered by traditional methods: some are pushed by hand and some use front-loader cargo tricycles. Either way takes effort, since a cart can weigh well over 100 pounds. Perez prefers the tricycle model, saying it allows him to cover more ground with less exertion.
[PARK SOUND, KIDS PLAYING]
After a couple of sales, Perez makes a wide loop around the park then heads off on the city streets, whistling along the way.
[DISTANT WHISTLE, PARK SOUNDS]
For the World Vision Report, I’m Shannon Young in Oaxaca, Mexico.
(NOTE: This segment originally aired on the January 9, 2010 program of the World Vision Report.)