Many years ago (hard to believe but it was probably about 40 years now) when I went to Portugal I was sad and a bit shocked to find out that one really cannot buy the best Mateus outside of that country - it is all kept 'in house' so to speak. That was the beginning of my disillusionment. I haven't drunk Mateus since (but that's ok since my tastes have changed anyway).
Sad but true, I think that happens in most countries that make goods that the locals like and have traditionally held dear as being indicative of their 'culture' - the exported version is of the lowest quality possible .. the dregs, so to speak. Add to that the eruption of corruption in every corner of commercial enterprises - and government - and one can have little trust in any label any more. If they can 'cut it', they will.
Buy local - do the same as they do if possible. Wish I didn't have to say that but if you don't these days, you will spend more money than needed and be scammed as well. I no longer purchase oils from Europe, especially since, if I want GMO canola oil, I can buy that cheaper here in Canada.
