The encyclopaedia of gravy
Scaling gravy up for a crowd: ratios that survive multiplication, the equipment that matters, and the bits that do not scale linearly.
Gravy scales well, which is part of why it has fed crowds for centuries. But a few things change when you go from a jug to a bucket.
The master ratio¶
Per 1 litre of finished gravy:
- 60 g fat
- 60 g plain flour
- 1 litre hot stock
- Seasoning at the end
Multiply freely. For 30 people at 150 ml each you need 4.5 litres: 270 g fat, 270 g flour, 4.5 litres stock.
What does not scale¶
| Thing | What changes |
|---|---|
| Roux cooking time | Longer — 5–8 minutes for a large batch, not 2 |
| Onion browning | Much longer, and needs a wider pan or two pans |
| Simmering time | Longer to reduce; allow 25–30 minutes |
| Seasoning | Less than proportional. Taste, then add. Salt compounds badly at scale |
| Yeast extract, Worcestershire | Also less than proportional — they are assertive |
| Lumps | Far more likely. Use a balloon whisk and add stock in stages |
Equipment that actually matters¶
- A wide, heavy-based stockpot. Thin pans scorch the roux and a scorched large batch is a catastrophe rather than an inconvenience.
- A balloon whisk, not a spoon.
- A conical or large sieve for straining.
- A vacuum flask or two, or a bain-marie for holding. See keeping gravy warm.
- A jug per table, warmed.
Method for 4.5 litres¶
- Melt 270 g of fat in a large stockpot.
- If using onions, brown 4 sliced onions first — 25 minutes over medium heat, stirring.
- Add 270 g flour and cook for 6 minutes, stirring constantly and scraping the base.
- Add 4.5 litres of hot stock in five or six stages, whisking each smooth. Adding it all at once at this scale guarantees lumps.
- Simmer for 25–30 minutes, stirring the base regularly so nothing catches.
- Season cautiously, taste, adjust. Strain into flasks.
💡 Chef's tip
Large-batch gravy is better the next day. The flour hydrates fully, the flavours settle and it reheats without splitting. Make it the day before and reheat gently, loosening with a little stock.
Freezing and reheating¶
Flour-thickened gravy freezes well for three months. Cool it fast, freeze in portions, and reheat gently from frozen with a splash of stock, whisking — it may look separated as it thaws and comes back together with heat and a whisk.
Cornflour-thickened gravy does not freeze well; it goes watery. Freeze the unthickened base and thicken on the day.