The Science of Alcohol Contamination
That next sip of your favorite drink might contain more than you bargained for.
Imagine enjoying a casual drink with friends, completely unaware that the very beverage meant for celebration could harbor dangerous, even lethal, chemicals. This is not a fictional thriller but a ongoing public health challenge faced globally. Alcoholic beverages are complex chemical cocktails, and when produced outside regulatory oversight, they can become vehicles for serious harm.
Globally, over a quarter of all alcohol consumed is "unrecorded"—produced, distributed, and sold outside formal government channels, missing crucial quality and safety checks1 .
In 2018, an incident in Iran led to 76 deaths and hundreds hospitalized from methanol poisoning. During the COVID-19 pandemic, nearly 300 people died in Iran after consuming alcohol based on false claims that it could cure or prevent infection1 .
This article delves into the science of analyzing alcoholic beverages, exploring how researchers determine their chemical composition, differentiate between safe and dangerous products, and work to prevent public health tragedies.
To understand the risks, we must first look at the key chemical players found in alcoholic beverages.
This is the primary alcohol humans seek when they drink. It's produced naturally by yeast during the fermentation of sugars and is responsible for the intoxicating effects of the beverage.
To understand how scientists evaluate beverage safety, let's examine a key 2025 study published in Applied Biological Chemistry that analyzed local specialty alcoholic beverages in Korea2 .
Researchers employed sophisticated technology to separate, identify, and measure volatile compounds in 29 different alcoholic beverages (9 wines, 10 beers, and 10 soju samples).
Each beverage sample was placed in a special vial with internal standards—known chemicals that help quantify unknown compounds.
Using a technique called Solid Phase Microextraction (SPME), a specialized fiber was exposed to the headspace above the liquid to absorb volatile compounds.
The extracted compounds were then transferred to a Gas Chromatograph-Mass Spectrometer (GC-MS). This instrument separates the complex mixture into individual components and identifies each one based on its unique molecular fingerprint.
The results were processed to identify and quantify 221 different volatile compounds present across the samples.
| Tool/Reagent | Primary Function |
|---|---|
| Gas Chromatograph-Mass Spectrometer (GC-MS) | Separates complex mixtures into individual components and identifies each compound based on its molecular weight and structure. |
| Solid Phase Microextraction (SPME) Fiber | Extracts and concentrates volatile organic compounds from the sample headspace for introduction into the GC-MS. |
| DB-WAX GC Column | A specialized capillary column that separates compounds based on their boiling points and polarity. |
| Ethanol-1,1,2,2,2-d5 (Deuterated Ethanol) | Serves as an internal standard for methanol quantification, improving measurement accuracy. |
| n-Alkane Standards (C7-C30) | Used to calculate Retention Indices, which help confirm the identity of unknown compounds. |
The analysis provided a comprehensive chemical profile of the tested beverages:
Wine samples showed the highest methanol content among the three beverage types, a natural result of fermenting fruit with high pectin levels2 . Fortunately, all detected levels were within safety limits.
Researchers found 25 different fusel alcohol components in wine, 16 in beer, and 14 in soju2 . The specific patterns created unique chemical fingerprints for each beverage type.
The main volatile compounds differed significantly by beverage. Wine was characterized by esters and alcohols, beer by esters, alcohols, and terpenes, and soju by esters, alcohols, and benzene derivatives2 .
| Beverage Type | Number of Samples | Methanol Content (Relative) | Number of Fusel Alcohol Components | Main Volatile Compound Classes |
|---|---|---|---|---|
| Wine | 9 | Highest | 25 | Esters, Alcohols |
| Beer | 10 | Intermediate | 16 | Esters, Alcohols, Terpenes |
| Soju | 10 | Lowest | 14 | Esters, Alcohols, Benzene Derivatives |
While the Korean study found legally produced beverages to be safe, the global picture of illicit alcohol tells a more concerning story.
The World Health Organization estimates that unrecorded alcohol constitutes 28.6% of global consumption, with this figure rising to over 56% in the Eastern Mediterranean and 69% in Southeast Asia1 . In some countries like Bhutan and Uganda, illicit alcohol can account for over 40% of total consumption1 .
Global Average
Eastern Mediterranean
Southeast Asia
Bhutan & Uganda
Illicit alcohol becomes particularly dangerous when adulterated with toxic substances. A 2015 Brazilian study that analyzed 152 suspected unrecorded beverages found multiple causes for concern:
| Country | Year | Reported Casualties | Suspected Source |
|---|---|---|---|
| Iran | 2018, 2020 | 76 deaths (2018); Nearly 300 deaths (2020) | Adulterated illicit alcohol, false COVID-19 cure1 |
| El Salvador | 2000 | >200 ill; 117 died | Methanol poisoning from low-quality alcohol1 |
| India | 1998 | 97 cases; 28 died | Methanol poisoning1 |
| Papua New Guinea | 1978 | 369 ill; 18 died; 4 blinded | Mixture of methanol and isopropanol1 |
| Spain | 1963 | 51 died | Methanol used in mixed alcohol liqueurs1 |
The chemical line between a enjoyable alcoholic beverage and a toxic one is frighteningly thin.
Scientific analysis, using sophisticated tools like GC-MS, plays a crucial role in monitoring this boundary, ensuring the safety of legal products and exposing the dangers of illicit ones.
The global presence of toxic illicit alcohol highlights the critical importance of effective regulation, market oversight, and public awareness. The next time you raise a glass, remember the complex and invisible chemistry it contains—chemistry that, when properly monitored, protects the celebration of life that alcohol so often accompanies.
References will be added here.