It doesn’t. The old saying “beer before liquor, never been sicker” is a myth with no scientific support. A controlled trial of 90 volunteers found that drinking order had zero significant effect on hangover severity, regardless of whether participants drank beer first or liquor first. What actually determines how sick you feel the next day is simpler: how much total alcohol you consumed and how drunk you got.
What the Research Actually Found
A 2019 study out of Witten/Herdecke University in Germany put this folk wisdom to a direct test. Researchers split 90 participants into three groups: one drank about two and a half pints of beer followed by four large glasses of wine, the second drank the same amounts in reverse order, and the third drank only beer or only wine. The next morning, everyone rated their hangover on a standardized scale measuring thirst, fatigue, headache, dizziness, nausea, stomach ache, and other symptoms.
None of the groups had meaningfully different hangover scores. Order didn’t matter. Mixing didn’t matter. The only factors that reliably predicted a worse hangover were how drunk participants felt during the night and whether they vomited. A separate large analysis confirmed this pattern: subjective intoxication alone accounted for about 38% of hangover severity, dwarfing every other variable measured.
Why the Myth Feels True
The saying persists because there’s a plausible-sounding logic behind it. Beer is relatively low in alcohol (around 5%), so people tend to drink it casually and in larger volumes. If you start with beer and then switch to liquor at 40% alcohol, you’re adding concentrated alcohol on top of an already rising blood alcohol level. By that point in the night, your judgment about how much more to drink is impaired. You end up consuming more total alcohol than you realize.
The reverse scenario, liquor then beer, feels safer because the high-alcohol drinks come first, when you’re still relatively sober and more likely to pace yourself. The beer that follows is lower in concentration, so it feels like you’re winding down. But the total amount of alcohol in your system is what drives the hangover, not the sequence it arrived in. A standard drink is a standard drink: 12 ounces of 5% beer contains the same 0.6 ounces of pure alcohol as a 1.5-ounce shot of 80-proof liquor.
How Beer and Liquor Hit Your Stomach Differently
There is one real biological difference between beer and liquor, but it has nothing to do with drinking order. Beer and wine are powerful stimulants of stomach acid. They trigger acid secretion at levels comparable to the maximum your stomach can produce. Distilled spirits like whiskey, gin, and vodka do not have this effect. The non-alcohol ingredients created during fermentation, not the alcohol itself, are responsible.
Beer also stays in your stomach significantly longer than liquor. In one study using ultrasound imaging, beer took an average of about 39 minutes to half-empty from the stomach, compared to roughly 26 minutes for whiskey. Red wine lingered even longer, at around 73 minutes. The carbonation, calories, and fermentation byproducts in beer slow digestion. This means beer sits in your stomach producing acid for longer, which can contribute to nausea and stomach discomfort independent of how drunk you are.
So if you’re someone who gets an upset stomach from drinking, beer itself may be a bigger culprit than liquor, regardless of when in the night you drink it.
Congeners and Why Some Drinks Cause Worse Hangovers
The type of alcohol you drink does matter in one specific way. Darker alcoholic beverages contain higher levels of congeners, which are chemical byproducts of fermentation and distillation. Bourbon, brandy, and red wine are high in congeners. Vodka contains almost none.
In experimental comparisons, bourbon produced noticeably worse hangover ratings than vodka at the same level of intoxication. That said, ethanol itself was still the primary driver of hangover symptoms, with congeners playing a secondary role. This means choosing clearer drinks can help at the margins, but it won’t save you from drinking too much.
What Actually Predicts a Bad Hangover
Forget the rhyme. The factors that reliably predict how awful you’ll feel the next morning are straightforward:
- Total alcohol consumed. More drinks means a higher peak blood alcohol concentration, which is the single biggest factor.
- How drunk you felt. Your subjective sense of intoxication during the night is the strongest predictor of next-day severity, accounting for more of the variation than any other measured factor.
- Whether you vomited. Vomiting during or after drinking was one of the strongest signals of a severe hangover to come.
- Hydration and food intake. Alcohol is a diuretic, and drinking on an empty stomach accelerates absorption.
- Congener content. Darker drinks contribute modestly to worse hangovers compared to clear spirits at the same dose.
Drinking order doesn’t appear on this list because it has never been shown to independently affect outcomes. The saying “beer before liquor, never been sicker” is a memory trick that mistakes correlation for causation. People who escalate from beer to liquor over the course of a night tend to drink more total alcohol. That’s what makes them sick, not the sequence.