Anightcap is a drink taken shortly before bedtime. For example, a small alcoholic beverage or glass of warm milk can supposedly promote a good night's sleep.[1][2]
Nightcaps can be neat or mixed. They should not be served chilled or on the rocks, because their point is to induce a feeling of warmth.[3] The hot toddy is usually considered the original nightcap.[4] Other traditional nightcaps include brown liquor like brandyorbourbon,[3] and cream-based liqueurs such as Irish cream. Wine, especially fortified,[5] can also function as a nightcap.[6] Since some nightcaps are made of amaro, a digestif, they are believed to also make settling into bed easier by promoting digestion.[4]
Infolk medicine, consuming a nightcap is for the purpose of inducing sleep. Alcohol is not recommended by many doctors as a sleep aid because it interferes with sleep quality.[7] But, in low doses, alcohol has sleep-promoting benefits,[1][better source needed] and some popular sleep medicines include 10% alcohol,[8] although the effects of alcohol upon sleep can wear off somewhat after several nights of consecutive use.[9]
A nightcap was originally alcoholic, since it makes the drinker feel warm and helps them sleep, just like the garment of the same name.[10] However, warm milk is often recommended as a nightcap for inducing sleep. It contains both tryptophan and calcium.[11] The effectiveness of warm milk for inducing sleep is disputed.[12]
In 1930, Ovaltine was advertised as "the world's best 'night-cap' to ensure sound, natural sleep".[10]
