Dijon Mustard substitutes
The best substitute for dijon mustard is stone-ground mustard: 1:1. Same base and the same emulsifying power. Only difference is the coarser grind, so a vinaigrette looks speckled rather than smooth.
Why it matters. Sharp, wine-based mustard that does double duty: it seasons, and its mucilage holds oil and vinegar together so vinaigrettes and pan sauces do not split. A mustard-free vinaigrette separates within minutes.
BestStone-ground mustard
●●●●●1:1
Keeps the flavour, acid and emulsifier roles.
Same base and the same emulsifying power. Only difference is the coarser grind, so a vinaigrette looks speckled rather than smooth.
Mustard powder + water + vinegar
●●●●○Per 1 tsp Dijon: 1/2 tsp dry mustard powder + 1/2 tsp water + a few drops of white wine vinegar; stand 10 min
Keeps the flavour, acid and emulsifier roles.
The standing time matters, since the heat only develops after the powder meets water. Sharper and more pungent than Dijon, and missing its white wine note.
Wholegrain mustard
●●●●○1:1
Keeps the flavour, acid and emulsifier roles.
The seeds stay intact, so a smooth sauce turns grainy, and it emulsifies a little less efficiently than smooth Dijon.
Yellow mustard
●●●○○1:1
Keeps the flavour, acid and emulsifier roles.
Milder, more vinegary and coloured with turmeric, so it tints a pale dressing yellow. It still emulsifies, but the flavour is much simpler.
Prepared horseradish
●●○○○Per 1 tsp Dijon: 1/2 tsp prepared horseradish + 1/2 tsp mayonnaise
Keeps the flavour, acid and emulsifier roles.
A completely different, more volatile heat that fades fast on cooking. The mayonnaise is doing the emulsifying, not the horseradish.
Mayonnaise
●●○○○1:1 by volume, in dressings only
Keeps the emulsifier role; loses flavour and acid.
Holds a vinaigrette together perfectly but contributes no acid and none of Dijon's bite, so the dressing tastes flat and needs extra vinegar and salt.
Other sauce substitutes
Measuring by weight instead? Use the kitchen converter.