Jack Wyrick
Jack Wyrick

What's The Science Behind Caffeinating Cocktails?

Jack Wyrick
Jack Wyrick

As a bartender at a coffee shop/bar hybrid, I’m often asked to mix coffee and booze. Most of the time, it tastes good, but just don’t ask me to reuse your cooled-off partial cup of coffee—it’s a health code violation on soooo many levels.

Mixing caffeine and alcohol isn't new, but the process has garnered a lot of attention as of late. With the recent nationwide ban on various types of alcoholic energy drinks, the interaction between caffeine and ethyl alcohol has received a good deal of academic press.

Cups of Caveats

Caffeine may be the most studied drug in history, but the mechanics of how the molecule interacts with other substances is still largely theoretical. Outside of social/behavioral studies, the combination of booze and caffeine is especially hard to study because researchers can’t ethically give their subjects as much booze and/or caffeine as it would take to mimic real world binge drinking.

As a result, subjects can only consume moderate amounts of each. At these levels, it appears that they may feel drunk, but their reaction times aren’t significantly different from subjects given the placebo.

[Safety Note: If you’re going to experiment on your own, be careful. This should go without saying, but never drink and drive. The combination of caffeine and alcohol may make you feel less drunk, but your blood alcohol content (BAC) still works like you’re only drinking booze.]

Another challenge in studying the interactions of caffeine and hooch is that the amount of caffeine in any given drink may vary. For example, caffeine levels in coffee depend on how it’s grown, roasted, ground, and prepared.

To complicate things further, energy drinks can vary in size from 1 oz shots to 23 oz cans. Within the size differences, different brands use varying levels of caffeine in similar products. For researchers, the variation means that it’s difficult to figure out how much caffeine causes the manifestation of its negative effects.

Queen Caffeine

We know that all people absorb caffeine in roughly the same way. However, many factors including alcohol, pregnancy, and even grapefruit juice can extend the molecule’s half-life within the body.

We also know that alcohol affects each person differently based on his/her gender, body mass, water content, and food consumption. When drunk together, caffeine can somewhat override the sleepiness and ataxia (lack of voluntary coordination in movement) that come with heavy drinking. Alcohol, in turn, can suppress the anxiety/jitteriness that comes with too much caffeine. What causes these changes is less clear.

Caffeine is known to unselectively block adenosine (a neuromodulator believed to promote sleep and suppress arousal) receptors in the brain. Since alcohol raises the levels of adenosine outside of cells, it would normally cause a drinker to get sleepy. In this article from the Journal of Caffeine Research, researchers posit that caffeine curbs sleepiness and ataxia by blocking a specific adenosine receptor—A1.

Increased levels of adenosine may suppress caffeine’s anxiety-causing compounds. Caffeine may also affect how a slightly different adenosine molecule (A2A), interacts with dopamine receptors to amplify the effects of dopamine released into the brain by alcohol.

Hit the Lab

If you’re going to experiment with mixing these two substances, be careful. Caffeine may exacerbate alcohol’s addictive aspects, so drink in moderation. Be safe, kids.

Irish Coffee

1 oz Irish cream (I prefer Irishman)
1 oz Irish whiskey

Pour ingredients into a mug. Top with coffee or a latte (if you have an espresso machine handy).

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Is There Any Point in Letting Red Wine Breathe?
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iStock

by Aliya Whiteley

At the end of a long day, few things beat simple pleasures like watching a good film, eating a bar of chocolate the size of your head, or drinking a big glass of red wine.

By this point in the evening, most people don’t want to be told that they need to uncork the bottle and let the wine sit for at least 30 minutes before it becomes pleasantly drinkable. Yet that's (by the letter of the unwritten law) what you're supposed to do.

But why? Well, let's start with the assorted historical reasons.

Red wine has been around since the Stone Age. In fact, in 2011 a cave was uncovered in Armenia where the remains of a wine press, drinking and fermentation vessels, and withered grape vines were uncovered; the remains were dated at 5500 years old. Early winemaking often had a ritualistic aspect: Wine jars were found in Ancient Egyptian tombs, and wine appears in both the Hebrew and Christian bibles.

The concept of letting wine "breathe" is, historically speaking, relatively new and probably has its roots in the way wine was once bottled and stored.

Traditionally, sulfur is added to wine in order to preserve it for longer, and if too much is added the wine might well have an ... interesting aroma when first opened—the kind of "interesting aroma" that bears more than a passing resemblance to rotten eggs. Contact with the air may have helped to remove the smell, so decanting wine may once have been a way of removing unwelcome odors, as well as getting rid of the sediment that built up in the bottom of bottles.

It’s also possible that the concept springs from the early 1860s, when Emperor Napoleon III asked Louis Pasteur to investigate why so much French wine was spoiling in transit. Pasteur published his results, which concluded that wine coming into contact with air led to the growth of bacteria, thus ruining the vino. However, small amounts of air improved the flavor of the wine by "aging" it. In bottles, with a cork stopper, the wine still came into contact with a small amount of oxygen, and by storing it for years the wine was thought to develop a deeper flavor.

However, how much of that actually matters today?

Many experts agree that there is no point in simply pulling out the cork and letting the wine sit in an open bottle for any period of time; the wine won’t come into enough contact with oxygen to make any difference to the taste.

However, decanting wine might still be a useful activity. The truth is this: It entirely depends on the wine.

Nowadays we don’t really age wine anymore; we make it with the aim of drinking it quickly, within a year or so. But some types of wine that are rich in tannins (compounds that come from the grape skins and seeds) can benefit from a period of time in a decanter, to soften the astringent taste. These include wines from Bordeaux and the Rhône Valley, for instance.

If you really want to know if a particular wine would benefit from being given time to breathe, try your own experiment at home. Buy two bottles, decant one, and let it breathe for an hour. Do you notice a difference in the taste? Even if you don’t, it's an experiment that justifies opening two bottles of wine.

One word of warning: No matter where a wine comes from, it is possible to overexpose it to oxygen. So remember Pasteur’s experiments and don’t leave your wine out of the bottle for days. That, friends, would be one hell of a waste.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

A Beer From the Middle Ages Is Making a Serious Comeback

Hop-forward beer is all the rage today, but in the middle ages many imbibers preferred brews that skewed towards the sweeter side. Now, centuries after it fell out of fashion, Atlas Obscura reports that gruit ale is making a comeback.

Gruit beer is any beer that features botanicals in place of hops. The ingredients that give the drink its distinctive sweet, aromatic taste can be as familiar as ginger and lavender or as exotic as mugwort and seabuckthorn. The herbs play the role of hops by both adding complex flavors and creating an inhospitable environment for harmful microbes.

It may be hard for modern beer lovers to imagine beer without hops, but prior to the 16th century gruit was as common in parts of Europe as IPAs are in hip American cities today. Then, in 1516, that style of beer suddenly vanished from pint glasses: That was the year Germany passed a beer purity law that restricted beer formulas to hops, water, and barley. Many of the key botanicals in gruit beer were considered aphrodisiacs at the time, and the rising Puritan movement helped push the brew further into obscurity.

Hops have dominated the beer scene ever since, and only in the past few decades have microbrewers started giving old gruit recipes the attention they're due. In 2017, the Scratch Brewing Company in Illinois released their seasonal Scratch Tonic, made from a combination of dandelion, carrot tops, clover, and ginger. The Põhjala Brewery in Estonia brews their Laugas beer using Estonian herbs, caraway, and juniper berries. Get in touch with your local microbrewery to see if they have their own version of the old-school beer in their line-up.

[h/t Atlas Obscura]

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