Before October arrives, the mills of Trás-os-Montes are already preparing for the new season. What happens behind the scenes of the olive harvest, in September.

A report by the EU's "More Than Only Food & Drink" campaign confirms that food tourism creates lasting consumers. For DOP olive oil from Trás-os-Montes, this isn't a trend — it's a strategy. And it's already happening.

A technical report published in Agroportal reveals that olive oil production costs in Portugal range from €2.5 to over €12 per litre. The traditional dryland groves of Trás-os-Montes are the most expensive to run — and the least supported. Here's what that means for producers, buyers and visitors.