Begin with the collections, not the picture books

The fairy tale you remember from childhood is almost certainly a distillation — softened, shortened and tidied up for a small listener at bedtime. That is a perfectly good way to meet a story. It is not the only way. If you want to read these tales as an adult, the first practical move is to go back to the source collections and read them cold, without the nursery filter.

That means Charles Perrault's Histoires ou contes du temps passé (1697), the Brothers Grimm's Kinder- und Hausmärchen (1812 onwards, and worth reading in more than one edition), the Norwegian tales gathered by Asbjørnsen and Moe, Joseph Jacobs's English collections, Andrew Lang's colour fairy books, Italo Calvino's Italian folktales and Katharine Briggs's work on British folklore. Read the prefaces and the notes at the back as well as the tales themselves. They tell you who was collecting, from whom, and what they quietly decided to leave out.

Read for the morality, not just the moral

Perrault ends his tales with a moral in verse — often two, the second of them gently ironic. In his Little Red Riding Hood, the girl is simply eaten; there is no huntsman, no rescue, and the closing lines warn young women about smooth-tongued strangers. The Grimms later added a huntsman and a second chance. Neither ending is wrong, but they are doing different jobs.

So ask, as you read: who is being warned, and who is doing the warning? A tale told by a servant to a servant's child carries different freight from one edited by a university professor for a bourgeois drawing room. The morality is rarely abstract. It is usually about hunger, marriage, obedience, money or survival, and it is aimed at somebody in particular.

Notice the social commentary underneath

Strip away the magic and many of these stories are documentaries. Hansel and Gretel opens with parents agreeing to abandon their children because there is not enough bread — and in earlier editions it is the mother who pushes for it, softened to a stepmother later on. The witch's gingerbread house is a dream of plenty in a landscape of famine.

Look for the economic machinery in other tales too:

• Marriage as transaction: dowries, alliances and the price of a bride run through Cinderella, Donkeyskin and countless others.
• Domestic danger: Bluebeard is a story about a husband with a locked room, and it reads very differently once you have known a few adults.
• Greed and its limits: The Fisherman and His Wife escalates from a cottage to a castle to the papal throne, and ends back in the mud.
• Class and cunning: Puss in Boots and Jack the Giant-Killer are fantasies of social climbing, told with a straight face.

Laugh at the dark parts

Adults often assume the old tales are grim. They are, but they are also frequently funny in a bone-dry way that children miss. In the Grimms' The Juniper Tree, a murdered boy returns as a bird and sings a cheerful song about being cooked and eaten by his own father, before dropping a millstone on the stepmother. It is horrific and it is a punchline.

The humour runs through the whole tradition. Clever Gretel eats the guest's roast fowl and then tricks her master into chasing him out of the house. The boy in The Youth Who Went Forth to Learn What Fear Was is so literal-minded that he bowls with skulls and shinbones to pass a haunted night. British folklore is full of it too — the shapeshifting Hedley Kow, who terrifies everyone and then leaves a woman delighted with her luck. If a tale makes you laugh and wince at the same time, you are probably reading it correctly.

Compare variants side by side

This is the single most rewarding habit you can develop. Almost every familiar tale is a version of a pattern recorded across continents and centuries. Scholars index these patterns by tale type, using the ATU system — Cinderella is ATU 510A, Little Red Riding Hood is 333, Bluebeard is 312 — which makes it easy to find cousins of a story you already know.

Read two or three variants together and watch what shifts. In Cinderella alone, the helper might be doves, a fairy godmother, a fish, a cow or a date palm. The famous slipper has been glass, fur and embroidered silk, depending on who was translating. In the Grimms' version the stepsisters mutilate their own feet to fit the shoe, and their eyes are pecked out at the wedding; in Perrault's, they are forgiven and married to courtiers. The bones of the story stay; the ethics move.

Make it a practice, not a nostalgia trip

Finally, a few things that turn occasional dipping into real reading:

• Read aloud. These were oral tales. The rhythms, repetitions and asides only work at speaking pace.
• Keep notes. A page per tale noting the helper, the obstacle, the ending and the odd detail pays off within a month.
• Read the apparatus. Introductions, footnotes and endnotes are where collectors argue with each other. It is surprisingly entertaining.
• Tell one to somebody. You will discover immediately which parts you remembered and which parts you invented.

Approached this way, fairy tales stop being childish things you have outgrown. They become what they always were: sharp, strange, funny, morally complicated stories that people told each other to get through the night — and which still have plenty to say to an adult reader who is willing to listen properly.