I’ve hit a spell of mistaking ripe fruit on wines from the old world for American oak when blinding in prep for my certified exam. Really, I think I’m just having issues recognizing new oak in general. For example, in the last week on three separate tastings:
I called McLaren Vale Shiraz on a 2014 Delas from St. Joseph. (Fruit was bright. Thought I smelled new oak)
i called Mendoza Malbec on a 2015 Pavie Macquin
I called Chianti Classico on a Big Bold 2012 1er Cru from Santenay with a lot of tannin (didn't catch the oak)
I remember even thinking while tasting that the structural issues didn’t quite match my calls; however, I have been convincing myself on the nose (which obviously comes early in the grid) with regards to American oak (or lack thereof) and letting that largely dictate my initial and final conclusions taking precedent over structural components.
I need help with oak!!!!
I'll second what the others have said, especially about practicing structure calls, and just add a couple things: I wonder if you or others are picking the right practice wines for the certified. Calling McLaren Vale on a St Joseph, calling Mendoza on a BDX...those old world wines should be significantly more earth and non-fruit driven than the new world wines you mistook them for. Picking the right examples to use isn't easy, but it's maybe the most important thing. There's plenty of iconic bottlings that can make blind tasting seem impossible, like Muga for Rioja, Do Ferreiro for Albariño, Altos las Hormigas for Malbec, to name a few.
Always find a moment to take you brain out of focus and think about big picture stuff with each wine. One friend of mine always used to tell me, before making your final call, sit back and enjoy the wine and things will come into a bit more focus. If recognizing oak isn't your strength, you can work around that. Study guides and mentors are truly important, but at the end of the day you have to find YOUR personal road map to getting each testable grape variety and style right.
With regards to the McLaren Vale call, it smelled like syrah, tasted like syrah, but because I was getting more fruit than I normally detect on northern rhone, I went to Australia, convinced myself, and I called McLaren Vale because it had too much acidity to be Barossa. That was the reasoning in my head at least, haha. But you are absolutely right, I should've known because of the earth dominant palate that it was old world.
The Pavie Macquin may be a non-typical right bank (though it is much darker and more "minerally" on the palate than a new world merlot). But the fig and fruit cake on the nose, again, made me think new world. After that I was pretty much doomed. My rationale in the Malbec call was basically "it's not jammy enough on the palate to be new world merlot so it has to be something with a jammy nose, but slightly darker palate, possibly south america, thus the malbec call. (and obviously a really stupid route to conclusion)
Again, both examples of me immediately making a conclusion based on fruit character on the nose rather than a more sound structural call. Alas, as you and the others have stated, I have to train myself to believe the structure!