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).

7 Surprising Uses for Tequila

Happy National Margarita Day! While you could celebrate by having a few drinks, you could also skip the hangover by unlocking one of tequila's amazing abilities outside of the glass. Many spirits are useful for activities beyond sipping (vodka, for example, is a great stain and odor remover), but tequila holds some particularly magical powers. Here are just a few of them.


In 2008, a team of scientists in Mexico discovered that when the heated vapor from an 80-proof tequila blanco was combined with a silicon or stainless steel substrate, it resulted in the formation of diamond films. These films can be used in commercial applications, such as electrical insulators, or to create one big fake diamond. Who knew that spending $50 on a bottle of Don Julio was such a wise investment?


Keeping with the science theme: In 2011, researchers at England’s University of Oxford suggested that we may one day be gassing up our cars with tequila. They identified agave, the plant from which tequila is produced, as a potential biofuel source—and a particularly attractive one, as the plant itself is not consumed by humans and can thrive in desert climates.


Scientists have long promoted the potential benefits of the agave plant for its ability to help dissolve fats and lower cholesterol. The bad news? These properties get a bit diluted when the plant is distilled into alcohol. Even more so when it's whipped into a sugary margarita.


Take three or more shots of tequila and you’re bound to pass out. A single shot can have the same effect—just not in that drunken stupor kind of way. Relaxation is one of the positive side effects of tequila drinking; a small amount (1 to 1.5 ounces) before bedtime can reportedly help you fall asleep faster and sleep more soundly.


Too much of a good thing may not bring a welcome turn of events for your liver … but your colon will thank you! Researchers at Mexico’s University of Guadalajara have identified the blue agave as a potentially helpful source for delivering drugs to the colon in order to treat colitis, IBS, Crohn’s disease and even cancer.


If Ernest Hemingway had known about the healing properties of tequila, his signature drink might have been a margarita instead of a daiquiri. In 2010, experiments conducted at Mexico’s Polytechnic Institute of Guanajuato revealed that the agave plant (which is high in fructans, a fructose polymer) could stimulate the GLP-1 hormone, aiding in increased insulin production.


“Plenty of liquids” is a well-known remedy for getting oneself out from under the weather. But expanding that definition to include a kicked-up shot of tequila makes a day laid out on the couch sound much more appealing. In the 1930s, doctors in Mexico recommended the following concoction to fight off a cold.

.5 ounce of tequila blanco
.5 ounce of agave nectar (to eliminate bacteria and soothe sore throats)
.5 ounce of fresh lime juice (for Vitamin C)

Though some people (including tequila companies) swear by its healing powers, others say it's hogwash.

Smart Shopping
16 Geeky Coasters to Keep Your Coffee Table Safe

Avoid unsightly ring stains on your coffee table with this delightful selection of coasters:

Mental Floss has affiliate relationships with certain retailers and may receive a small percentage of any sale. But we only get commission on items you buy and don’t return, so we’re only happy if you’re happy. Thanks for helping us pay the bills!

1. FLOPPY DISKS; $22.79

Floppy disks are not obsolete—at least in your living room area.

Buy on Amazon.

2. MARIO; $20

Mario Question Mark Block Coaster Set

Unfortunately, no coins will be coming out of these coasters, but they will keep your table dry.

Buy on Etsy.

3. GAME OF THRONES; $12.99

Game of Thrones coasters
HBO Shop

Avoid a royal mess with house sigils of houses Targaryen, Stark, Baratheon, and Lannister.

Buy at the HBO Shop.

4. PACMAN; $20.95

Use these on a black table to recreate the retro video game.

Buy on Epic Giftables.

5. AGATE; $35

Rock on: These fancy agate coasters will look solid resting under your glass.

Buy on Amazon.

6. ELEMENTS; $56.99

These glowing coasters are perfect for chemists, Breaking Bad fans, and anyone who forgot to pay their electric bill.

Buy on Amazon.


Build your own coaster with this LEGO-esque design.

Buy on Amazon.

8. STAR TREK; $16.63

Star Trek ship coasters

This ceramic set celebrates all the best ships from Star Trek.

Buy on Amazon.

9. DR. WHO; $22.99

Just make sure you don’t accidentally send your glass into a different time period when you set it down.

Buy on Amazon.

10. RILAKKUMA; $1.95

Rilakkuma coaster

Cover your counter space with the cute face of Rilakkuma.

Buy on Bonanza.


Set of wood burned coasters featuring the crest of each Harry Potter house

All the houses are present in this set of wood coasters.

Buy on Etsy.

12. FALLOUT; $25

fallout coasters

Just because it’s the end of the world doesn’t mean all manners go out the door: Never forget to use a coaster!

Buy on Etsy.

13. BRAIN; $19.99

This set comes with 10 coasters, each with a slice of brain specimen. When you’re not using them, you can stack them together to create a full brain.

Buy on Amazon.


Aang and his entourage face off on these wooden coasters.

Buy on Etsy.

15. BUFFY AND CO; $20

Getting totally wigged by the idea of a stained table? All your favorite characters from Buffy the Vampire Slayer can give you an assist.

Buy on Etsy.


Studio Ghibli Stone Tile Coasters

These coasters feature scenes from the classics My Neighbor Totoro, Princess Mononoke, Spirited Away, and Howl's Moving Castle.

Buy on Etsy.


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