How did winemakers first figure out how to remove alcohol from wine without destroying it? Why is it so difficult to perfect the flavours and aromas in wine once the alcohol is removed? Why do some non-alcoholic wines keep their fruity aromas while others seem to lose everything?

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.

Highlights

How was the German winemaker, Carl Jung, a pioneer in the field of no and low alcohol wine?

Why is the reverse osmosis process better suited to small alcohol adjustments rather than full dealcoholization?

How has the spinning cone column become one of the most effective tools for removing alcohol from wine?

Why is it so challenging to preserve flavour and aroma in non-alcoholic wines?

Why are low alcohol wines often more successful than alcohol free wines?

How can vineyard and fermentation choices reduce alcohol while preserving wine character?

Why do lower alcohol wines preserve a sense of place more successfully than fully de-alcoholized wines?

How do beer producers have more technical options for making low alcohol products than winemakers?

What is the connection between alcohol and mouthfeel?

Why is Sauvignon Blanc often the most successful base for alcohol free wine?

How does Wes envision the future of non alcoholic wine?

Key Takeaways

How did winemakers first figure out how to remove alcohol from wine without destroying it? The story goes that Carl Jung was somewhere in India, in the Himalayas, and he noticed that water boiled at a lower temperature and started thinking about, oh, well you know, they had a family winery and I wonder if we can take ethanol out if we boiled it at a lower temperature. Understanding, of course, classic distillation ethanol boils at around 70-something degrees and water would boil at 100. So you could boil your ethanolic solution, remove the ethanol, trap it on this side, leave your water here or whatever solution you have your ethanol in, and then keep the ethanol. That's classic distillation. Normally we keep the distillate, we keep the alcohol, and get rid of what we've taken it out of. Now we want to keep what we've taken it out of and get rid of the ethanol. So that was the whole premise behind vacuum distillation.

Why is it so difficult to perfect the flavours and aromas in wine once the alcohol is removed?

When that wine comes off the spinning cone column, it's not a pleasant drink. It's extremely acidic. You've concentrated the acids by about a third, and as well, you've lost all the flavor. Also the flavor that balances out all that acid is gone as well. We need to do a lot of work in building that back up. We should use more tools that we have to try to build some of these up, to build flavor. Now, of course, from the economics behind this, these are not expensive products. So we can't just whack everything in there and hope for the best. We have to have some judiciousness when it comes to how much these things cost and how much you can add, and how we can do this to recover what we've taken out and put back so that it's more cost effective. This is all part of the research that we're working on.

Why do some non-alcoholic wines keep their fruity aromas while others seem to lose everything?

When the yeast eat the sugar in the grape juice, those sugars are all attached to all kinds of other chemical compounds. The yeast come along, they eat the sugar, and release the flavor compound. And so those fermentation products, most of them are esters and organic acids. Now the esters are the really pretty things that we smell, all the fruity flavors. And the organic acid portions of those, they're less appealing. Now, when you put those through the dealcoholization machine, the spinning cone column in particular, you get the stinky stuff staying, and you get the nice stuff going. Within Sauvignon Blanc, you lose the acetate, but actually three-mercaptohexanol smells lovely. It smells like passion fruit, and so that stays. Where if your wine doesn't have thiols, something like Chardonnay, which is much lower in thiols, 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/371.

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