Custard Ratio Calculator
Calculate egg yolks, cream, milk, and sugar for any custard — crème brûlée, pastry cream, or stirred custard — by yield and style.
Understanding Custard Ratios
Custard is an egg-thickened liquid — the proteins in egg yolks coagulate when heated, transforming cream or milk into a smooth, rich sauce or set dessert. The ratio of eggs to liquid controls texture, from barely-set panna-cotta-like creaminess to firm sliceable custard.
Types of Custard and Their Ratios
| Type | Egg Yolks per 250 ml | Use |
|---|---|---|
| Pouring custard (crème anglaise) | 3 yolks | Ice cream base, sauce |
| Crème brûlée | 4 yolks | Individual ramekins, blowtorched top |
| Pastry cream (crème pâtissière) | 4 yolks + 25 g starch | Éclair filling, tart base |
| Baked custard / flan | 2 whole eggs + 1 yolk | Sliceable, firm texture |
The Role of Each Ingredient
- Egg yolks — Lecithin and proteins provide richness and thickening power.
- Heavy cream — Fat content makes the custard silky. Use 35%+ fat cream for best results.
- Milk — Lightens the texture. Using all cream makes it too heavy.
- Sugar — Sweetens and slightly raises the coagulation temperature, giving a smoother result.
- Salt — A small pinch enhances all other flavors dramatically.
- Vanilla — Infuse a split bean in the warm cream before straining for best flavor.
Temperature Is Everything
Custard proteins set at around 82–85°C (180–185°F). Above 90°C (194°F), the eggs scramble and the custard curdles. Always cook over gentle heat and stir constantly for stirred custards. For baked custards, use a water bath (bain-marie) to ensure gentle, even heat.
Test for Doneness
A properly cooked stirred custard coats the back of a spoon — draw your finger across it and the line should hold cleanly. Baked custard is done when the edges are set but the center still has a slight wobble.
Storage
Custard keeps refrigerated for up to 3 days. Press plastic wrap directly onto the surface to prevent a skin from forming.