Answer: The first recorded exposure of Europeans to vanilla was through the Aztecs, who used it to flavor their chocolate drinks.
It's not hard to pollinate the blooms, but it takes ideal conditions for the vines to flower. High temperatures and humidity, intense, bright light, and a very pourous medium (such as orchid bark/soil) will encourage bloom. To pollinate the flowers, use a toothpick. In the morning, lift the flap over the stigma and gently prick up a pollen clump from one of the yellow green flowers and place it on the pistil of a different flower.
I couldn't find a reference that said exactly who discovered how to pollinate the plant by hand. Its possible that no one knows exactly who discovered this!
Here are two interesting vanilla web sites:
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