The nightcap as a drink is an expression that dates back to the 1700s, when folks donned nightcaps as a way of warming themselves and thus promoting better sleep. In a sense the nightcap drink, which can really be any type of alcoholic drink, does provide warmth, and also generally makes one a little sleepy. Alcohol at first sedates, and it lowers the body’s temperature, making one feel warmer.

Another potential origin for the term nightcap is the idea of the “capping” the evening. When you were fully dressed in earlier times, such dress was not complete until you put on your hat. In other words you weren’t finished until you were capped. Nightcap may thus be used to signify an evening’s finish, and is so used in numerous films where the lovely young lady invites a gentleman to her apartment or home for a nightcap. This is, at least in PG films, the final act of a date and a last goodbye before the evening is over.

As mentioned, a nightcap can be drinks of any kind, but must usually contain alcohol. Some contend that drinks like cocoa, chamomile tea or warmed milk also can be called nightcaps. If you do want to promote healthy sleep, you’re better off with the tea or milk than you would be with anything with alcohol in it. Yet taking an alcoholic drink before bed was common practice. Charles Dickens, in the novel David Copperfield has a lovely description of Betsy Trotwood taking her nightly drink of wine and water into which she dips strips of toast. When Betsy is faced with financial reverses she switches to drinking ale instead.

Physicians used to recommend a moderate amount of alcohol before bedtime for those people suffering from difficulty sleeping, but now they are considerably wiser to the effects of alcohol, even in small amounts on the sleep cycle. Though an occasional drink before bed is fine, if you regularly consume alcohol at bedtime, you’re quite likely to have sleep difficulties. Alcohol may make you feel drowsy and warm at first, but it also tends to halve the amount of REM sleep you get.

It also has a tendency to promote much lighter sleep in the later part of your sleeping time, which means you may wake up more frequently and more quickly move through sleep cycles. If you feel tired at night, just imagine how tired you may feel after a poor night’s sleep that began with an alcoholic drink. As Olympia Dukakis comments of her husband’s drinking in the film Moonstruck that when he drinks too much, he sleeps too hard and is up when he should be down.

There are several bartending groups that suggest a perfect recipe for the nightcap. These often involve a blend of coffee liqueur or crème de cacao with milk. Some include scotch, whiskey or other hard alcohols. Technically any drink with alcohol, taken before bedtime, caps the evening and is thus a nightcap.