The Chemistry of Wine

By Brian Lemay 20 comments

You know that guy in your group of friends that always brings wine to the party JUST so he can talk about it? He’s always saying things like “Ooh! There are notes of bacon! Reaaaally swish it around you’ll get those hints of cream soda. Really taste the purple.” It may sound strange, and it may make you get different friends, but all those different smells and tastes come from complex chemistry that gives each bottle of wine its unique flavors. [REACTIONS INTRO] First off, sorry high rollers, but no matter how much you paid for it, a bottle of wine is about 98 percent water and ethanol. It’s the remaining couple percent that makes wine taste like wine, and more specifically makes a shiraz taste different than a pinot noir. It comes down to three things: grapes, soil and climate. If you think all wines are pretty
much the same, they ain’t! There are more than 10-thousand wine grape varieties in the world, all producing different tastes and smells when made into wine. Dirt is also a big factor. Famous winegrowing areas like France, California and Chile have distinct minerals in their soils across their vast geographies that make wines different. There are up to 60 trace elements in wine that help identify a soil or grape variety. Researchers can even identify
chemical fingerprints in wine that point to the exact trees used to make the wooden barrels many wines are aged in. It’s like wine CSI, but with 100% less Caruso. The other huge factor is climate. Winemakers know that cold climates produce lower alcohol wines with more subtle flavors, while warm regions make more robust wines. That’s because the ripening process that produces sugars and many flavor molecules, slows at cooler temperatures. Once the grapes are crushed, natural and added yeasts begin to eat the sugars, turning them into alcohol and carbon dioxide. The carbon dioxide gas is allowed to bubble out. Like yeast farts. But as yeasts digest sugars and other compounds present in grape juice, they produce a host of molecules that give wines their flavor. Yeasts make acetic acid and other acids that give wines their tartness. Derivatives of pyruvic acid,
contribute to red wine’s color. Yeasts also make diacetyl, which give Chardonnays their “buttery” aroma. And then there are the hundreds of other molecules that give wines their very specific flavors. For example, scientists have figured out that methoxypyrazines make some wines taste a bit like bell peppers. And it doesn’t take many
molecules to tickle the taste buds. two parts per TRILLION of methoxypyrazines. Different molecules give the flavor or smell of grasses or nuts, while other common wine flavors, like chocolate or even tobacco, haven’t been pinned to a specific molecule. Another big component of wine’s flavor is tannins. Tannins are big molecules that come from the skin and seeds of grapes and also the wood in barrels used to age the wine. Look at that big sucker. Some tannins trigger taste receptors on your tongue and can give wine a bitter taste. Others can make your mouth feel dry,
known as “astringency”. Remember gang, taste and smell are very complex processes, both chemically and in how your brain interprets them. So yes, you may not taste bell pepper or chocolate and someone else might. Don’t worry about it. Just enjoy! Thanks to our friends at Azari Vineyards in Petaluma, California for letting us drop by their gorgeous winery and raise a glass. Find out more about them in the description. If you want to keep this booze cruise going, check out our video on craft beer chemistry. And our friends over at Speaking of Chemistry actually took a bath in a bunch of red wine. Why would they do such a thing? You don’t want to miss that video! Trust me! And click subscribe to make sure you never miss one of ours either. Thanks for watching, Chemheads.


Guilherme Marques

Jul 7, 2015, 12:08 pm Reply

That Pinot Noir easter egg was awesome!


Jul 7, 2015, 12:57 pm Reply

no italian wine was mentioned but chilenian and californian were? damn


Jul 7, 2015, 2:02 pm Reply

To whoever reads this,
I hope you have a wonderful day and no matter what stay happy as that is what matters most in life,
You are truly amazing and no one can ever take that away from you,
Be happy and enjoy life,
We don't have long on earth so make the most of it,
Have a wonderful day, Cheers, from doge in a rain coat!


Jul 7, 2015, 2:10 pm Reply

Meh wine tastes like shit compared to fucking beer in my opinion.

James Craver

Jul 7, 2015, 2:47 pm Reply

I'm a grown man, and I giggled when you said "yeast farts" (it was the sound effect that did it)


Jul 7, 2015, 3:39 pm Reply

That woman's hand is holding the wine glass the wrong way… You hold cognac glass that way.


Jul 7, 2015, 8:04 pm Reply



Jul 7, 2015, 10:30 pm Reply

Hey mommy, can I have your glass of grape juice?

Sampath Rapuri

Jul 7, 2015, 10:55 pm Reply

How about a episode on the human body


Jul 7, 2015, 3:46 am Reply

Still waiting for this fantastic channel to get more views.


Jul 7, 2015, 3:15 am Reply

The Galilee is known for its wine.

Phil Volkers

Jul 7, 2015, 1:51 pm Reply

No mention of sulfites?! Really?!

Robert Kelly

Jul 7, 2015, 6:39 pm Reply

From my experience, people slowly migrate over time from sweet white to dry white to red.  This is because of the bitter astringency of tannins.  It would be great if you could do an entire show on grape tannins and how they react to oak tannins and how both react to saliva, the protein in your mouth and foods that are high in protein.  Thank you for doing this series.

GiggitySam Entz

Jul 7, 2015, 10:54 am Reply

Soil doesn't affect taste as much as the microorganisms that get in at all steps of the making process.


Dec 12, 2015, 3:11 pm Reply

Great video!
Could you do some more about the chemistry of odors / fragrances?


Dec 12, 2015, 8:16 pm Reply


Arash snai

Sep 9, 2016, 5:19 pm Reply

can you make a video about yeast please?


Jun 6, 2017, 9:40 pm Reply

That wasn't much chemistry.

Loren Miller

Sep 9, 2018, 6:37 am Reply

Might want to check your facts on the source of wine color compounds and diacetyl

alamin khan

Feb 2, 2019, 1:23 pm Reply

Did you guys hear it at 1:56?

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