For several years I was inviting Virtual Tourist readers for wine harvesting in this friend's farm absolutely free. Maybe we may continue in other pages...
Some people pay much money to participate in the very interesting works of traditional harvesting. They are right, it really worth the price.
"Enoturismo" is a fancy new word created in Portugal and Spain to mean those tourist trips concentrated in wine discovery and tasting, with such demand that most farms do charge big money to accept tourists in their works.
( A friend of mine is a tourist operator that charges 4000 € for a week of "Enoturismo" - always full!)
However, it is still possible to enjoy that experience for free.