Au jus (say it "oh-ZHOO", French for "with juice") is the thin, unthickened beef juice served with prime rib and French dip sandwiches. You make it by deglazing the drippings from a beef roast with beef stock, then simmering to reduce and concentrate the flavour before seasoning. It is not gravy and must never be thickened with flour or cornflour (cornstarch) — thin is the whole point.
Au jus is one of those things that sounds fancy and turns out to be dead simple. It is just the thin beef juice you serve with prime rib or a French dip — drippings, stock, a good scrape of the pan, and a little patience while it reduces. The one rule a granny would drum into you: do not thicken it. Thin is the whole point. Here is how to make it from drippings, how to make it when you have none, and why it is not gravy.
| Au jus | Beef gravy | |
|---|---|---|
| Base | Beef drippings and beef stock | Beef drippings and beef stock |
| Thickener | None | Roux (2 tbsp fat + 2 tbsp flour per 250 ml / 1 cup liquid) or cornflour (cornstarch) slurry |
| Texture | Thin, pourable | Thick, coats a spoon |
| Served with | Prime rib, French dip sandwiches | Roasts, mash, biscuits |
| Golden rule | Never thicken it | Thicken it |
What au jus actually is (and how to say it)
Au jus is French for "with juice", and it is said oh-ZHOO. On a menu, "prime rib au jus" means prime rib served with its own juice. It is a thin, pourable, unthickened beef jus — nothing like a thick, spoon-coating gravy.
The flavour comes from two things: the drippings, which are the fat and browned juices left in the pan after roasting beef, and good beef stock. You loosen those browned bits, add stock, and let it reduce so the flavour concentrates. That is the whole trick.
Because it stays thin, au jus is for dipping and pouring — spooned over slices of prime rib, or set in a little bowl for dunking a French dip sandwich. If you thicken it, it is no longer au jus. It is gravy, and a different thing entirely.
How to make au jus from drippings
This is the classic method, straight after roasting a piece of beef. You want about 500 ml (2 cups) of finished jus.
1. Lift the roast out and let it rest. Tip the roasting tin so the fat pools in one corner and spoon off most of it, leaving the dark browned juices and a spoonful or two of fat behind.
2. Put the tin over a medium hob (or scrape everything into a saucepan). Pour in about 500 ml (2 cups) beef stock and let it come up to a simmer.
3. Deglaze: scrape the bottom hard with a wooden spoon so every browned bit lifts and dissolves. That fond is where the flavour lives.
4. Simmer to reduce by about a quarter, 8-10 minutes, until it tastes deep and beefy. Do not thicken it.
5. Season with salt and pepper to taste. A splash of Worcestershire sauce is traditional. Strain if you like it clean, and serve hot.
No-drippings au jus (from beef stock)
No roast, or you want au jus for a French dip without cooking a whole rib? You can build a very good jus from good beef stock alone. Use the best stock you can — this is where the flavour comes from now.
Melt 1 tbsp butter in a saucepan and, if you like, soften a small chopped shallot or a little onion in it for a couple of minutes. Pour in 500 ml (2 cups) beef stock and 1 tsp Worcestershire sauce. Bring to a simmer and let it reduce for 10-15 minutes to concentrate. Season with salt and pepper.
For more depth, brown 1 tsp tomato purée in the butter first, or add a splash of red wine and cook off the raw edge before the stock goes in. Keep it thin. Strain and serve hot alongside the beef.
Au jus is NOT gravy — the difference that matters
This is the part people get wrong. Au jus and gravy start from the same place — beef drippings and stock — but they part ways at one step.
Gravy is thickened. You cook fat and flour into a roux (a "2 and 2": about 2 tbsp fat plus 2 tbsp flour per 250 ml / 1 cup liquid for a medium gravy), or you stir in a cornflour (cornstarch) slurry. It coats the back of a spoon.
Au jus is not thickened at all. It stays thin and pourable so it soaks into a slice of prime rib or a French dip roll. Add flour or cornflour and you have quietly turned your au jus into gravy — which defeats the purpose.
So: same drippings, same stock, one choice. Thicken for gravy, leave it thin for au jus.
Questions we get asked
How do you pronounce au jus?
It is said oh-ZHOO. It is French for "with juice", so "prime rib au jus" means prime rib served with its own beef juice.
Is au jus the same as gravy?
No. They start the same way — from beef drippings and stock — but gravy is thickened with flour or cornflour (cornstarch) and au jus is left thin and unthickened. Keeping it thin is the entire point of au jus.
How do you thicken au jus?
You do not. A proper au jus is thin and pourable by definition. If you thicken it with a roux or a cornflour (cornstarch) slurry, you have made gravy instead. To make it taste stronger without thickening, simmer it longer to reduce and concentrate the flavour.
Can you make au jus without drippings?
Yes. Use good beef stock as the base, warm it with a little butter, a splash of Worcestershire sauce and, if you like, a softened shallot, then simmer 10-15 minutes to reduce. Season and serve thin.
What is au jus served with?
Most often prime rib, where it is spooned over the slices, and French dip sandwiches, where it is served in a little bowl for dunking. Any roast beef is happy with it.
What are drippings?
Drippings are the fat and browned juices left in the pan after roasting beef. You spoon off most of the fat, keep the browned bits, and deglaze them with stock to build the jus.