Name: The Science of Alcohol: From Beer to Bourbon
Uploaded: 2021-05-05T13:12:22.000Z
Duration: 9 min 29 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

For humans, food and drink are more than just a necessity for survival.

They're a huge part of our culture and our history, shaping our lives on a daily basis.

And alcohol has had perhaps the strongest, uh, influence on us.

From soft alcohols like beers and wines to hard liquors like whiskey and vodka, booze

comes in many shapes and styles, and can be found all over the world.

But how did humans discover alcohol, and how is it made?

Thanks to some microscopic organisms, some time, and some crafty chemistry, we've gotten

pretty good at our creating our own hooch!

The alcohol we're describing today is ethanol, which is actually just one type of alcohol.

But it's the only one that's safe to drink in large quantities, because we've developed

the ability to metabolize, or break down and eliminate its toxic components.

Ethanol occurs in nature thanks to fermentation -- the process of breaking sugars down into

And humans -- and our non-human ancestors -- have been able to metabolize that ethanol

From examining our DNA, some scientists estimate that our ancestors developed the ability to

metabolize ethanol around 10 million years ago -- way before we were mixing our own cocktails.

Back then, we hadn't even split off from the ancestors of chimpanzees.

But that adaptation could have been helpful for our early primate ancestors by allowing

them to eat fermented fruit without getting sick.

Evolving humans must have enjoyed what they felt when they ate fermented fruits, because

figuring out how to create our own fermented beverages quickly became a centerpiece of

In fact, there are some researchers who believe that our desire for alcohol is what drove

us to develop agriculture, which would have given us constant access to the grains and

starches needed to produce our own booze.

The earliest known evidence of the deliberate creation of an alcoholic beverage is 9,000

years old, discovered in some pottery in the Yellow River Valley in China.

This drink was some sort of wine, and contained rice, honey, and grapes.

In 2005, researchers actually recreated the drink based on a chemical analysis, and apparently

Archaeologists think that around the same time people were originally making this stuff,

barley beers and grape wines were being produced in the Middle East.

People probably made those early drinks by leaving fruits and grains in covered containers

Eventually, they'd open the containers, and the liquid inside would be alcoholic -- but

for thousands of years, no one knew exactly why this was happening.

Thanks to modern science, we've got it pretty much figured out.

Beers are produced by fermentation, which comes from the Latin fervere, meaning “to boil.”

Which makes sense, because the mixture of grains and water does bubble during the process.

And a beer really only needs four basic components: grain, water, yeast, and hops.

Different varieties of these components mixed in different ratios can give each beer a distinct flavor.

There are also different ways to do the beer-brewing itself.

But here's how the process generally works:

The first step in making beer involves cooking grains in water, which produces a mix called

The heat activates enzymes within the grains and begins to break the starches down into

Different grains are used for different kinds of beer; dark roasted grains are used for

darker, heavier beers like stouts while light grains are used for light beers, like wits

Once they've all been cooked down, the grains are removed from the pot and the remaining

At this point, the liquid is called the wort, and it's during this step that the primary

flavoring element of the beer is added -- hops.

Hops are actually flowers, harvested from a climbing vine called Humulus lupulus.

Beers have always been flavored with herbal mixtures, and we're not sure when or why

hops became the herb of choice -- but it was first noted as being part of brewing sometime

Adding hops to beer helped balance the sweet flavors from the grains with an acidic kick,

but more importantly, the hops kept it from spoiling, so the beer lasted longer.

We now know that hops produce antibacterial compounds called alpha and beta acids, which

help keep the beer free of bacteria and support the growth and survival of the yeast.

These acids mainly give the beer its distinctive bitterness, but different varieties of hops

can also give beers citrusy, floral, and even piney notes.

After the boil, the liquid is rapidly cooled to prevent bacterial contamination and oxidation,

Once the wort is cooled, the yeast is added to begin the fermentation process.

Yeast -- in this case, a particular variety called Saccharomyces cerevisiae -- is a microscopic,

Yeast rely on sugars for energy, so they eat up the sugars in the wort and spit out carbon

The carbon dioxide is why the liquid bubbles, and the ethanol is why there's alcohol in beer.

During the first phase -- the primary fermentation -- there's a lot of yeast hard at work.

All that waste carbon dioxide is allowed to escape the container, while the ethanol is

After a while -- usually a minimum of two weeks -- most of the sugar has been consumed

In some cases, the beer is transferred to bottles with a small amount of sugar, to help

fuel the remaining yeast through the last step: secondary fermentation.

The beer is then tightly capped, and the carbon dioxide and ethanol produced within the container

are preserved, finally turning the liquid inside into the fizzy, intoxicating beverage

Wine production is similar to beer-making in a lot of ways.

It's just that, instead of grains, wines use fruit to produce alcohol.

And as you probably know if you've ever tasted a $3 bottle of wine, different varieties

of grapes, and how they're prepared, can dramatically affect the flavor of the wine.

First, the grapes are crushed. Back in the day, people used to stomp on the grapes in

big tubs, but now it's generally done with specialized mechanical crushers.

The resulting mixture of skins, pulp, and juices is called the must.

Whether the wine is a red or a white usually depends on this step.

White wines are often made from green grapes, and red wines are generally made from purple

grapes -- but the color of the grape doesn't automatically determine what type of wine

In fact, purple grapes can be used to produce both kinds of wine.

Leaving the dark grape skins sitting in the must will lead to a red wine, while separating

the juices from the skins and pulp quickly will lead to a white wine.

Those dark grape skins also contain tannins -- compounds that a chemist would call polyphenols.

They're made of lots of connected rings of carbons attached to an oxygen and a hydrogen.

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The Science of Alcohol: From Beer to Bourbon

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