Key lime pie

Ingredients

• Graham crackers or digestives250 g
• Butter — melted110 g
• Sugar50 g
• Condensed milk400 g
• Egg yolks4
• Limes8
• Double cream300 ml
• Icing sugar30 g
• Salt1 pinch

Salt and spices grow more slowly than the rest: doubling a dish does not double the pepper.

Weight converts to ounces and volume to cups. Grams of flour are not turned into cups, because that depends on how tightly it is packed.

Method

1. 1

   Crush the crackers to fine crumbs and mix them with the melted butter, sugar and a pinch of salt.

   10 min

2. 2

   Press the crumbs into a tin, working them up the sides, and bake at 175 °C for ten minutes.

   15 min

3. 3

   Beat the yolks with the zest of two limes until pale, about three minutes.

   5 min

4. 4

   Add the condensed milk and beat three minutes more, until the mixture thickens.

   5 min

5. 5

   Pour in the lime juice in a thin stream with the mixer running; the mixture thickens in the bowl.

   5 min

6. 6

   Pour the filling into the base and bake at 160 °C for fifteen minutes, until the edges set and the centre still wobbles.

   18 min

7. 7

   Cool it and chill it four hours, then top with cream whipped with the icing sugar.

   15 min

About the dish

The filling thickens on acid rather than heat: lime juice curdles the proteins in condensed milk and the mixture sets in the bowl. The oven only stabilises it.

The pie was invented in the Florida Keys in the late nineteenth century, where there was no fresh milk and condensed milk arrived in tins. It is a dish born of having no refrigeration.

The juice has to be freshly squeezed. Bottled juice brings a bitterness from its preservatives, and once the filling sets nothing removes it.

Worth knowing

• — The pie should not brown. It is pale by definition, and a golden crust means the filling overheated and will crack.
• — True Key limes are smaller and sharper than ordinary limes. Ordinary ones work, but you need slightly more juice — taste the mixture before baking.
• — Chilling is essential and the freezer is no substitute. Fast chilling gives grain instead of a creamy set.

Nutrition

Per serving at the base yield, calculated from the ingredients rather than measured in a lab.

Calories

520 kcal

Protein

8 g

Fat

30 g

Carbs

56 g

More from United States

• New England clam chowder — A thick clam soup with cream, potato and bacon. No tomato — that is a matter of principle.
• Buffalo wings — Unbreaded wings in a sauce of hot pepper sauce and butter. Salt draws the moisture out before baking.
• Pulled pork — Pork shoulder smoked ten hours at low heat and pulled into threads.