Dr. Wes Pearson on the Science of Blind Tasting and the Chemistry of Non-Alcoholic Wine

What is it really like inside the legendary Len Evans Tutorial, where elite tasters spend a week benchmarking themselves against the world's greatest wines? What are the surprising lessons that come from tasting ultra-rare wines blind? What happens when famous labels disappoint, or a legendary bottle proves why it earned its reputation? Why did the McLaren Vale's ancient bush-vine Grenache go from being a "blend filler" to one of Australia's most exciting fine wine styles? How did a handful of producers help drive that transformation?

In this episode of the Unreserved Wine Talk podcast, I'm chatting with Dr. Wes Pearson, a senior research scientist at the Australian Wine Research Institute in Adelaide.

You can find the wines we discussed at https://www.nataliemaclean.com/winepicks.

Key Takeaways

The current vintage of the Romanée-Conti Grand Cru is about $15,000 on release. Not only was the legendary Len Evans Tutorial a great opportunity to taste these holy grail wines that would otherwise be inaccessible, but it was also insightful to taste them blind because, as he says, sometimes the emperor has no clothes and they're not quite all they're cracked up to be. Or they are, which is actually a better story. It's a career-changing benchmarking exercise for a professional taster. Wes still refers back to that tasting when judging competitions years later.

Grenache loves the heat, so it was often picked after Shiraz. Therefore, it traditionally had lots of alcohol and flavour and was used as backfill. In 2010, a few McLaren Vale producers realized they could be fine wine with Grenache and started changing the way it was harvested and made.

The science behind how yeast releases flavor compounds when they eat sugar during fermentation is fascinating. The esters have fruity flavors, while the organic acids are less appealing. When the spinning cone column dealcoholizes Sauvignon Blanc, you lose the less appealing acetates, but the three-mercaptohexanol compounds smell lovely, like passion fruit, and they stay. However, if the grape doesn't have these compounds, like Chardonnay, you don't get that retention of that character.

About Dr. Wes Pearson

Dr Wes Pearson is a senior research scientist and sensory group manager at the Australian Wine Research Institute in Adelaide. He holds a BSc in Wine Biochemistry from the University of British Columbia, a diploma in Applied Sensory and Consumer Science from the University of California Davis and a PhD from Charles Sturt University. He has worked in the sensory group at the AWRI since 2010 and has completed hundreds of sensory studies and authored over 25 research papers in that time. He is an alumnus of the Len Evans Tutorial and of Wine Australia's Future Leaders program and sits on the board of directors for the McLaren Vale Grape Wine and Tourism Association. He has judged at multiple capital city and regional wine shows and has been an educator/judge for the AWRI's Advanced Wine Assessment Course for more than a decade. He is also an accomplished winemaker, having made wine in Canada and France, and currently makes wine under his Juxtaposed label in McLaren Vale, South Australia.

To learn more, visit https://www.nataliemaclean.com/podcast.