Gravy for a crowd

How to scale gravy up without it going watery, how much to make per person, and how to serve twenty plates without a queue.

How much per person

Allow 100ml a head for a normal roast and 150ml if it is Christmas or if your family are the sort who flood the plate. For twenty people that is two to three litres, which is more than most domestic pans hold, so plan the vessel before you plan the recipe.

Always make more than you think. Leftover gravy freezes. Running out halfway down the table does not.

Why scaled up gravy goes watery

A big pan has a smaller surface area relative to its volume, so it reduces far more slowly than a small one. Multiply a recipe by four and cook it for the same time and you get four times as much thin gravy.

Two fixes. Either reduce in a wide pan or roasting tin across two hob rings, which gives you the surface area back, or accept it and thicken slightly more than the recipe says. Do not just boil it for hours, because the seasoning concentrates even when the water does not leave fast enough.

Seasoning does not scale in a straight line

Salt roughly does. Strong things like Marmite, mustard, anchovy, chilli and stock cubes do not. Multiply those by about three quarters of what the maths says, taste, and go from there. It is far easier to add than to take away.

Getting it on the table

Make it the day before. Reheat in the biggest pan you own, then split it between two or three jugs and warm them with boiling water first so the gravy does not cool the moment it is poured in. Two jugs going round in opposite directions halves the queue.

A slow cooker on low, or a warmed vacuum flask, will hold gravy safely for a couple of hours and gives you a hob ring back on the day it matters most.