The encyclopaedia of gravy
Plain wheat flour thickens gravy through starch gelatinisation. It must be dispersed in fat or cold liquid and cooked out, and 30 g per 500 ml is the standard dose.
How much¶
| Consistency | Flour per 500 ml |
|---|---|
| Thin (chips, dipping) | 20–25 g |
| Standard pouring | 30 g |
| Thick (mash, pie filling) | 40–50 g |
A level tablespoon of plain flour is roughly 15 g, so "two tablespoons per pint" is the traditional rule and it is about right.
Why it must be cooked¶
Two reasons.
Taste. Raw flour tastes pasty and slightly chalky, and it carries through into the finished gravy. Two minutes in the fat plus five to ten minutes simmering in the gravy eliminates it.
Texture. Starch granules need time and heat to swell fully. Under-cooked gravy continues to thicken on the plate and feels grainy.
Why it must be dispersed¶
Dry flour meeting hot liquid gels on the outside of each clump and seals dry flour inside — a lump. Disperse it first, either in fat (a roux) or in cold liquid (a slurry). See avoiding lumps in gravy.
Plain, self-raising or strong?¶
Plain flour. Self-raising contains raising agents that give a faintly soapy taste and can foam. Strong bread flour has more protein and less starch, thickens slightly less and can go stringy. Wholemeal works but is gritty and darkens the gravy.
Browned flour¶
An old British technique: flour toasted dry in a low oven or a dry pan until biscuit-coloured, then stored. It gives a nutty flavour and darker colour without a long roux, though it thickens less. Mrs Beeton recommends keeping a jar of it. See gravy in domestic cookery.