We've all been there, waking up on the morning after a big summer brew festival. Your eyes flutter open and you're crumpled at the bottom of your tent that was haphazardly pitched on a hill the night before. You unzip the flap and the blinding morning sun pierces through. Empty cans, cups and tasting glasses are everywhere, and you start to piece together the night before. You check your Untappd history, the only lasting record of the night's events, to find an incredibly long list of barrel aged sours, double IPAs and barleywines. Your head begins to pound, and your mouth feels like a desert. Beer nerds love to spend time researching the science of how a beer is made and fermented, but not much thought is placed on what happens to it once it enters your body, and how it reacts when you've had too many.
Lack of sleep
A few things happen when you drink a beer. The first effect, before any alcohol starts moving around your system, is a connection between the brain and olfactory nerve. Thousands of different flavor compounds connect with their corresponding unique flavor receptors in your olfactory gland and send signals to the brain. When these signals are received in particular combinations the brain perceives the flavor as "good" and sends chemicals into the brain. Hops have a lot of flavor compounds that trigger the feel-good chemicals in the brain, even being used in teas to help people calm down and sleep well. However, alcohol can mess with the 24-hour circadian cycle, and although it has an initial sedative effect, sleep had under the influence of alcohol is typically shorter in duration and has little restorative value.
Fusel alcohols in the brain and body
Once alcohol makes its way into your blood stream through the stomach lining and intestine it contributes to that feeling in the brain that helps lower inhibitions and judgement. In small amounts, beer is a great "social lubricant" promoting good conversations, laughter and fun times. In large amounts, the alcohol causes headaches, nausea, dizziness, and vomiting. This is where some of the science comes in to play. The alcohol in beer is primarily ethyl alcohol. The good news about ethyl alcohol is that the body can break it down and get rid of it, if given enough time. This rate varies from person to person, and is different in males and females. However, during fermentation, yeast can also create several fusel alcohols. It often happens in beers that are fermented in warm environments or when a lot of simple sugar is used. For these reasons, most Belgian beers have small amounts of fusel alcohols in them. These types of alcohols cannot be broken down by the body and cause headaches, while the brain struggles to remove them, and they build up after a long night of drinking.
Alcohol also acts as a diuretic, forcing water from the cells through reverse osmosis, causing greater production and excretion of urine. Ethanol also inhibits the production of antidiuretic hormones in the pituitary gland, which would normally help the kidney re-absorb more liquid. This one-two punch makes bathroom trips frequent and negates the "beer is 90% water" idea that keeps people from hydrating during a session of drinking. If given enough alcohol, the body will try to remove some of it through vomiting, which only increases the overall levels of dehydration. Dehydration and loss of electrolytes lead to dryness of mouth, dizziness and extreme thirst, all major hangover symptoms. Hydration before, during and after the event are key to getting rid of these symptoms. Coconut water and electrolyte sports drinks are a go-to hangover beverage.
Low blood sugar
In large amounts beer can also cause hypoglycemia. The constant presence of alcohol and the digestion of the other sugars in beer can often lead the body into a hypoglycemic state, where the blood sugar levels become very low and lactic acid builds, causing overall body weakness and mood changes. Many people turn to fresh fruit like bananas and apples to help get some glucose back in the system on the morning after.
Low levels of alcohol in the stomach for extended amounts of time causes the stomach to create more acid. This adds to a lot of the nausea, vomiting and the other general gastrointestinal issues that follow a night out. Buffering compounds (think Tums) can help counteract the additional stomach acid.
The positive side of all of this is that while you may feel like you're dying in the moment, almost every hangover ends, usually without treatment, and the body is very good at repairing itself. Humans have been trying every conceivable "cure" for hangovers for about as long as humans have been consuming alcohol, from pickled herring, to milk and honey, to some "hair of the dog that bit you." Ibuprofen or Asprin can help with the headaches, but often cause increased stomach acid production. Tums or other acid buffering tablets can help some of the gastrointestinal pain, but aren't a perfect cure. Caffeine in coffee can help counteract the overall lack of sleep and weakness associated with the hangover, but introducing coffee to an already upset stomach can cause added problems. Water and electrolytes are key to reducing the dehydration symptoms and fruit with some simple sugars and fiber can help the low blood sugar, but these both take a lot of time to equalize. After many clinical trials, and much testing, there seems to be no single miracle pill that can get rid of a hangover. The only tried and true cure is to not drink so much, but if you were good at that you wouldn't be reading this in the first place! Switching to smaller sampling glasses, lighter alcohol styles of beer and alternating beer with water are all good ways to stay on an even keel. At the very least, hopefully knowing what's going on inside your body the next time you head out to a beer festival or camping trip, can help you prevent some of the awful day after symptoms, and live to drink another day!
Ben enjoys good beer, strong coffee and loud music. This Certified Cicerone continues expanding his knowledge of beer, hands-on. He’s the guy on the brewery tour asking too many questions. Famously open-minded, you can find him drinking a 3-year-old imported sour beer one night, and an American light lager the next. When he’s not writing for gotbeer.com, Ben can be found cooking, home-brewing, rock climbing, or playing the drums.