---
title: "Coat the back of a spoon: what it means in cooking — Tiny Plates"
description: "A sauce that coats the back of a spoon is thick enough to cling in an even layer and hold a line drawn through it. It is the classic test for custard."
url: "https://www.tinyplates.dev/glossary/coat-the-back-of-a-spoon"
---

# Coat the back of a spoon

A sauce that coats the back of a spoon is thick enough to cling in an even layer and hold a line drawn through it. It is the classic test for custard.

Also called Coats a spoon.

"Coat the back of a spoon" is a test for when a sauce or custard is thick enough. You dip a spoon in, lift it out and look at the back. If the liquid clings in a smooth, even layer and does not run straight off, it is ready. French cooks call this stage [nappe](https://www.tinyplates.dev/glossary/nappe). It is used for pouring custard, ice cream bases, pan sauces and glazes.

## How to do it

1. Dip a wooden or metal spoon into the sauce and lift it out.
2. Turn it over and hold it level.
3. Run a fingertip across the back of the spoon, through the sauce.
4. Look at the line you made.

## How to tell it is done

* **Ready:** the coating is even and opaque, and the line stays clean with sharp edges. The sauce does not flow back into it.
* **Not yet:** the sauce is thin and see-through, and the line fills in at once. Keep cooking and test again in a minute.
* **Too far, for egg custards:** the sauce looks grainy or has small lumps. It has started to curdle.

For an egg custard, this stage is reached at about 77 to 82°C (170 to 180°F). A [thermometer](https://www.tinyplates.dev/glossary/thermometer) helps. Do not let a custard without starch go above about 82°C (180°F).

## Why it works

As an egg custard heats, the yolk proteins slowly set and thicken the liquid. As a sauce [reduces](https://www.tinyplates.dev/glossary/reduce), water evaporates and the sauce gets thicker. Either way, there is a point where the liquid is thick enough to hold on to a surface. The spoon test shows that point without special tools.

## Common mistakes

* Testing on the front of the spoon. The curve holds liquid and fools you. Use the back.
* Raising the heat to speed things up. Custard can go from thin to curdled very quickly. Keep it low and stir all the time.
* Testing a sauce right off a high flame. Sauces thicken more as they cool, so a sauce that already looks thick in the pan may be too thick on the plate.

## In recipes

"Cook until it coats the back of a spoon" is the usual phrase. For custard, take the pan off the heat as soon as it does, and pour it into a cold bowl to stop the cooking. Strain it if you see any lumps. It also comes up when you [temper eggs](https://www.tinyplates.dev/glossary/temper-eggs) for a sauce.

## Related terms

* [NappeNappe is the thickness at which a sauce coats the back of a spoon and holds a clean line when you draw a finger through it. It is the test for custards.](https://www.tinyplates.dev/glossary/nappe)
* [Temper eggsTempering eggs is slowly whisking hot liquid into beaten eggs so they warm up without scrambling. It is the key step in custards and pastry cream.](https://www.tinyplates.dev/glossary/temper-eggs)
* [ReduceTo reduce is to simmer or boil a liquid uncovered so water evaporates, leaving a smaller amount that is thicker and more intense in flavor.](https://www.tinyplates.dev/glossary/reduce)
* [Crème pâtissièreCrème pâtissière is a thick custard of milk, egg yolks, sugar and starch, used to fill eclairs, tarts and doughnuts. Here is how to make it smooth.](https://www.tinyplates.dev/glossary/creme-patissiere)
* [ThermometerA kitchen thermometer checks the heat of meat, oil, sugar and your oven, so food is safe and cooked how you want. Here is which type to use and how.](https://www.tinyplates.dev/glossary/thermometer)

[More in recipe phrases](https://www.tinyplates.dev/glossary/category/recipe-phrases)[Every term from A to Z](https://www.tinyplates.dev/glossary)