The encyclopaedia of gravy
Cornflour is pure maize starch. It thickens fast, gives a glossy translucent finish, is gluten-free, and thins again if boiled hard.
How to use it¶
- Mix with cold water — roughly 1 part cornflour to 1.5 parts water — until completely smooth.
- Pour into simmering liquid, whisking.
- It thickens within 30–60 seconds.
- Simmer no more than 2 minutes.
⚠️ Watch out
Never add dry cornflour to hot liquid. It seizes instantly into lumps that will not disperse. Cold slurry, always — see avoiding lumps in gravy.
Strengths and weaknesses¶
| Strength | Weakness |
|---|---|
| About twice as powerful as flour by weight | Thins if boiled hard or long |
| Instant — no roux needed | Gives a slightly slippery, "Chinese-takeaway" texture at high doses |
| Glossy, translucent finish | Doesn't look like traditional gravy |
| Gluten-free | Freezes badly — goes watery on thawing |
| No raw-flour taste to cook out | Adds no flavour of its own |
When to choose it¶
- Gluten-free gravy, where flour is out.
- Last-minute rescue of a gravy that is too thin — see fixing gravy that is too thin.
- Glossy sauces where a matte finish would look wrong.
- When you have no fat to make a roux with.
When not to¶
- Gravy you intend to freeze. Freeze the unthickened base and thicken on the day.
- Gravy that will be held hot for hours — it gradually thins. See keeping gravy warm.
- When you want the traditional opaque look of a Sunday gravy.
Relatives¶
Arrowroot — clearer and glossier still, thickens at a lower temperature, expensive, dislikes reheating. Potato starch — very glossy, breaks down quickly. Tapioca starch — stringy in savoury sauces; better in pies.