Alcohol and Caffeine are two of the most widely used psychoactive substances in the world. With such powerful cultural significance, it is easy to see similarities between the two chemicals. However, these two compounds are produced in very different ways.
Beer is traditionally brewed from water, grain, hops, and yeast, none of which contain caffeine. Furthermore, the fermentation process that makes beer alcoholic is unable to produce caffeine. But while most beer is not caffeinated, beers flavored with coffee, chocolate, or other additives may contain small amounts of caffeine.
Read on to find out more about the science of caffeinated beer and to see which popular beers might give you a buzz!
Does beer have any caffeine in it?
Beer is traditionally made from just four ingredients (water, grain, hops, and yeast), none of which contain any caffeine. However, beer may include caffeine if it is flavored with ingredients like coffee or chocolate.
The process of making beer is an incredible example of ingredients transforming themselves through chemical reactions: namely, ethanol fermentation produced by living yeast. Yeast can transform a mixture of water, hops, and malted grain into an effervescent, alcoholic beverage laden with aromatic flavor compounds.
But unlike alcohols, caffeine is an alkaloid produced by living plants and fungi, meaning that there is no way for yeast to produce it through fermentation. Since neither grains or hops contain any caffeine, the only way beer will ever contain caffeine is through a flavoring or additive.
In addition, large amounts of added caffeine in alcoholic beverages has been considered unsafe by the United States government since 2010. So while you can still buy mildly caffeinated coffee stouts, don’t expect to find any highly caffeinated malt beverages.
Is there any caffeine in alcohol?
Ethanol and Caffeine are very different compounds; they are produced by different mechanisms and affect your brain in different ways. Not only is there no caffeine in ethanol, but caffeine is never produced in the process of ethanol fermentation.
Alcohol is produced through the metabolic process of yeast, also known as ethanol fermentation. In this process, yeast breaks down sugar for energy before releasing the waste products of carbon dioxide and ethanol. Ethanol, like other alcohols, is soluble in water and acts as a depressant by inhibiting brain functions when consumed.
Caffeine, on the other hand, is a complex alkaloid that is built up by living plants as a pesticide. As opposed to alcohol, a waste product that is released by breaking down larger compounds, caffeine is constructed by combining smaller compounds into a complex chemical. Caffeine acts as a stimulant by stimulating the release of dopamine and adrenaline in the brain.
Because alcohol is made by breaking down larger compounds while caffeine is made by joining smaller ones together, there is no way that these two substances would be produced through the same chemical reaction.
There’s nothing stopping these two compounds from mixing after they are made, though, and there are many examples of commercial beverages that include both alcohol and caffeine.
Most coffee beers do include some caffeine
Because of its high caffeine content, any beer flavored with coffee will be at least slightly caffeinated. Since few microorganisms break down caffeine, and none of those are involved in the process of ethanol fermentation, the caffeine content in coffee beer depends on the amount of coffee used and the brewing process.
There are a few ways that coffee beers can be flavored: some recipes mix beer with cold-brewed coffee, while others call for an infusion of dry roasted coffee beans. Others still call for a mixture of both methods
Both of these methods are examples of cold infusions, which is the coffee brewing method that releases the least amount of caffeine. It is estimated that cold-brewed coffee only contains around 75% as much caffeine as you would see in a hot brewed cup of coffee.
For this reason, beers flavored with cold-extracted coffee like Guinness Nitro Cold Brew Coffee will generally contain quite low levels of caffeine.
How much caffeine does coffee beer have?
While coffee beers will always include caffeine, the exact caffeine content is rarely listed. Based on the amount of coffee used during the brewing process, coffee beers could contain up to 50mg of caffeine per 12 fl oz. bottle.
When you compare that to the 70-140mg of caffeine found in an average cup of coffee, it becomes clear that the addition of coffee is more for the flavor than the effects of caffeine.
Will coffee beer keep you awake?
Since the average cup of coffee contains about twice as much caffeine as a 12 oz. can of coffee beer, you might have as much difficulty sleeping as if you drank a small amount of coffee before bed.
However, it’s important to recognize that the science of sleep has changed a lot regarding caffeine and sleep.
Though it may seem counterintuitive, research published in the academic journal Sleep has shown that moderate caffeine intake within four hours of going to bed has little to no effect on the quality of sleep.
On the other hand, the same study showed that alcohol use within four hours of bedtime was strongly linked to fragmented, restless sleep.
So while the caffeine content of coffee beer probably won’t keep you awake, the alcohol content could very well keep you up and prevent restful, uninterrupted sleep.
Other examples of beers that include caffeine
Since beer will only ever contain caffeine as a result of naturally caffeinated flavorings, you can safely assume that any beer boasting a caffeinated ingredient may contain a small amount of caffeine. Apart from coffee, other ingredients considered sources of caffeine are chocolate, tea, kola nuts, yerba maté, guarana berries, guayusa, yaupon holly, and around 60 other plants.
Coffee is the most common caffeinated additive used for brewing beer, and also the flavoring with the highest caffeine content.
Some of the popular coffee beers on the market are:
- Guinness Nitro Cold Brew Coffee Stout
- Harpoon Dunkin’ Coffee Porter
- Founders Kentucky Breakfast Stout
- Left Hand Milk Stout
- Funky Buddha Maple Bacon Coffee Porter
While there are a lot of beers marketed as chocolate beers, the reality is that most of these don’t actually contain any chocolate, and therefore no caffeine. Rather, chocolate beers are frequently made from a type of dark malt that closely mimics the flavors of chocolate.
Despite this, there are some beers that contain real chocolate. However, even these will contain very little caffeine due to the low amount of chocolate used for flavoring. If you were to use 2 oz. of baker’s chocolate in a 5-gallon homebrew, for example, each 12 oz. bottle would contain less than 1 mg of caffeine.
Chocolate beers that contain real chocolate include:
- Yuengling Hershey’s Chocolate Porter
- Sam Smith Organic Chocolate Stout
- Dogfish Head Theobroma
- Cascade Brewing Cocoa Cardamom
- Southern Tier Brewing Choklat Imperial Stout
Tea-infused beer is an up-and-coming trend with similarly negligible caffeine content.
Like with coffee beers, the caffeine content in tea-infused beers will depend greatly on the infusion method and the type of tea used but is generally almost imperceptible.
Some examples of beer infused with black tea, green tea, and yerba maté include:
- Milwaukee Brewing Co. O Gii
- Four Peaks Senchado Green Tea Lager
- Garage Brewing Co. Jasmine Green Tea-Bird
- Three Taverns Lord Grey
- Shipyard Brewing Co. TeaBrew
Is it safe to mix alcohol and caffeine?
In 2010, the FDA and FTC issued warnings to a number of companies that added caffeine to their beverages. Drinks like Charge, Moonshot, FourLoko, Joose, and Max were identified as dangerous. Many of the companies that marketed these beverages have since changed their formula to remove any added caffeine.
According to the CDC, large amounts of caffeine in alcohol can mask the depressive effects of the drug, making users feel more alert and less impaired than they actually are, leading to more frequent and dangerous alcohol-related accidents and overdose.
These effects were especially harmful in many of the drinks listed above due to their high alcohol and caffeine content, with about 12% alcohol per volume and over 500 mg of caffeine.
These amounts have been frequently compared to the equivalent of drinking a six-pack of beer and five cups of coffee at once.
That being said, the negligible amounts of caffeine and lower levels of alcohol in coffee beers are nowhere near the levels seen in caffeinated alcoholic beverages prevalent before the 2010 ban.
While it is still important to drink responsibly and remain aware of your alcohol intake, you shouldn’t have to worry about the low levels of caffeine found in coffee beers with no added caffeine.