In many people's minds, the difficulty with alcohol isn't the feeling of inebriation. It's the fact that it takes so long to dissipate. Responsible drinkers never drive while they're drunk and the influence of alcohol can create similar impediments to normal functions as well. (Don't try performing complex mathematical equations or delivering a comprehensive treatise on the policies of the current Presidential administration while you're drunk.) The length of time required to sober up depends on how much alcohol you've consumed.
Alcohol Effects on the Body
When you take a drink of alcohol, it's absorbed into the bloodstream through the walls of the small intestine. It then spreads throughout the body, affecting the function of your brain and motor functions. The body eventually gets rid of alcohol by oxidising it through the liver, but that process doesn't take place quickly.
How Long Does it Take to Get Sober?
Alcohol is the only ingredient in any beverage which matters as far as sobering up goes. Different types of alcoholic drinks take different amounts of time to process because they contain different amounts of alcohol. Generally speaking, it takes a healthy liver 1 hour to oxidise 29.6ml worth of alcohol. That's roughly the amount in 1 bottle of beer, 1 glass of wine or 1 shot of hard liquor. If you drink more alcohol than that in a single hour, it takes a correspondingly longer period to sober up.
It's best to think of that time period as the body's efforts to regulate your alcoholic intake. Strictly speaking, waiting it out is the only effective way to sober up. That's why experts suggest "sleeping it off" by taking a nap in a warm, safe place. Napping disengages your body from any additional activities and gives your body a chance to oxidise the alcohol in your system.
Alleviating the Symptoms
Many of the so-called "cures" for drunkenness are actually methods of treating the symptoms of alcohol. Black coffee, for example, contains caffeine which focuses your mind to focus and reduces your drowsiness, but it doesn't necessarily sober you up. Similarly, drinking lots of water enables your body to stay hydrated, which cuts down on the effects of hangovers. Neither technique makes you less drunk or mitigates the effects of alcohol on your motor skills or judgment. Both simply make it easier to cope with the after effects of drinking, instead of actually allowing one to become sober.
The best way to sober up quickly is to plan for it while you're drinking. Eat a good meal before or during your alcohol consumption, that way you can decrease the alcohol effects. The food absorbs the alcohol and slows the rate at which it is taken into the body. Alternate alcoholic drinks with water and take time between drinks. It allows your body to process it at its own rate, lessening the effects of alcohol but also decreasing the time it takes to sober up.