A Dijon Vinaigrette That Does Not Split

Method

1. Put the vinegar, salt and a good grind of pepper in a clean jar with a tight lid, and swirl it until the salt has dissolved. Salt dissolves in vinegar and not in oil, so the order matters.
2. Add the mustard, seal the jar and shake for 10 seconds. The vinegar should turn cloudy and thicken slightly.
3. Add the shallot now if you are using it, so the acid takes the raw edge off it while you finish the dressing.
4. Pour in about a third of the oil.
5. Seal and shake hard for 15 seconds, until the mixture looks pale and opaque rather than layered.
6. Add another third of the oil and shake hard again for 15 seconds.
7. Add the last of the oil and give it a final 20 seconds.
8. Taste it on a leaf rather than off a spoon. Neat vinaigrette always tastes sharper than it will on a salad.
9. Adjust with a pinch of salt, a splash of vinegar or the teaspoon of honey, then shake once more.
10. Dress the leaves a minute or two before they go to the table, and use less than you think. They should look glossy, not wet.

This is the dressing to make when the salad is the point rather than the side. For what those salads look like in December, salads for Christmas lunch works through the leaves that survive a hot room, and our green salad with preserved lemon dressing is a different jar built on the same shake.

Questions we get asked

Why does mustard stop a vinaigrette from splitting?

Ground mustard seed is an emulsifier. The seed coat gives up a soluble gum that thickens the vinegar and slows the oil droplets moving through it, and the fine particles settle on the surface of each droplet so two of them cannot merge on contact. The effect is not permanent, which is why a homemade dressing still wants a shake before it goes on. It is the difference between a dressing that holds for a whole meal and one that separates on the way to the table.

What is the ratio of oil to vinegar in a vinaigrette?

Three parts oil to one part vinegar by volume, which is 180ml of oil to 60ml of vinegar in the jar above. Go to 4 to 1 for delicate leaves that a sharp dressing would flatten, and 2 to 1 for bitter leaves or a salad carrying cheese, bacon or roasted vegetables, where the fat blunts the acid. Mustard is what lets you hold the sharper end of that range without the dressing splitting.

How long does homemade vinaigrette keep?

A plain oil, vinegar and mustard dressing keeps in a sealed jar in the fridge for around two weeks. Add fresh shallot, garlic or soft herbs and it becomes a few-day proposition, and it belongs in the fridge rather than on the bench. Expect the oil to cloud and set when cold. Twenty minutes at room temperature and a hard shake brings it back, and if it has separated in the meantime it will re-emulsify, because the mustard is still in there.

Can you use seeded mustard instead of Dijon in a dressing?

You can, and it will taste good, but it will not hold as well. Whole seeds keep most of their gum and their surface area locked inside, so a seeded mustard does far less emulsifying work than the same spoon of smooth Dijon. The useful move is both: a teaspoon of Dijon to hold the dressing together, plus a teaspoon of Lancaster seeded mustard for the pop of whole seeds through it.

A jar of Dijon earns its shelf space several times a week. Mustang Dijon mustard is $12.95 for 270g and the 110g mini is $6.95, both from The Regimental Condiment Company, and the bottles that go with them sit in olive oil and vinegars. Shipping is free Australia-wide on orders over $100, and orders placed before 12pm on a weekday are dispatched the same day from our Corio, Victoria warehouse, tracked with Australia Post. If the jar is for somebody else's kitchen, the same condiments turn up inside our Christmas hampers.