Your reader Gary said he could not find a certain olive oil taste he had found in Portugal. I am also a huge fan of Portuguese olive oil. During my travels there, I was told that the Portuguese let the olives sit for 10 days before pressing, which gives the oil its unique pungency and flavor. Is this true?
Each country has their own unique varieties of olive which contribute to regional olive oil flavors. Portugal has the Cobrancosa and Verdeal for example. But letting olives sit after harvest will cause the fruit to heat up, spoil and ferment. The resultant oil will have high acidity and taste defects such as "fusty, musty, moldy, rancid". The oil would not qualify as extra virgin under current International Olive Council testing.
In most of the world in the past 2000 years processing capacity did not keep up with the harvest so olives sat and fermented. The traditional lever or screw olive press with reed mats was difficult to keep clean and encouraged oxidation and off tastes. Clay storage containers of the day were poorly sealed and oil quickly went rancid if it was not already. Oil was not an expensive condiment but a necessary source of calories so consumers were resigned to the taste and came to expect and prefer this traditional taste of the oil. In some parts of the world they still do. Mort Rosenblum in his book Olives, The Life and Lore of a Noble Fruit has a great story about traveling to a tiny town in North Africa where with great reverence he was offered a bottle of very musty rancid oil which the locals treasured.
In the past 50 years there has been a big improvement in olive oil processing, storage and distribution. If a producer can process the olives quickly in enclosed centrifugal centrifuges, store the oil in modern containers such as stainless steel, and prevent exposure to light and heat during distribution, the oil will be of higher quality and the price much higher. No modern producer would deliberately let their olives sit for 10 days if there was any way to prevent it.
I am hoping that the flavor your prefer is that of the unique Portuguese varietals. The Portuguese do not have a powerful marketing lobby so sell most of their oil to consolidators in Italy or Spain where it is blended with other oil. If it is the musty olive taste you are after, that is fine, as they say, "it is a matter of taste" and some people will prefer a flavor that others label a defect. Of course there is not a big export market for defective oil so you are not likely to see it in mainstream markets.
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