Mayonnaise, hollandaise & vinaigrette
Oil and water will not mix on their own. With an egg yolk, a little mustard and some patience, you can make them hold together as a thick, glossy sauce.
Why it works
An emulsion is one liquid broken into tiny droplets and spread through another that it would normally refuse to mix with. Mayonnaise and hollandaise are oil-in-water emulsions: billions of droplets of oil or butterfat suspended in a small amount of water, from the yolk, lemon juice or vinegar. Packed tightly enough, those droplets jostle against each other and the sauce turns thick and opaque, even though it is about 80 per cent fat.
Left alone, droplets bump into each other and merge until the oil floats back to the top. An emulsifier stops that. Egg yolk is full of them: lecithin and proteins that have one end attracted to water and the other to fat. They coat each droplet and keep it apart from its neighbours. Mustard helps in the same way, which is why it turns up in mayonnaise and vinaigrette alike.
This is why the oil goes in slowly at first. At the start there is only a spoonful of watery yolk, and every drop of oil has to be broken up and coated before the next arrives. Add too much at once and the yolk is swamped, the oil stays in a slick, and nothing thickens. Once a thick base has formed, there are plenty of droplets to break new oil against, and you can pour in a steady stream.
Warm sauces add heat to the picture. Hollandaise and béarnaise use butter, which has to stay liquid, and yolks, which thicken usefully as they warm and scramble if they get too hot. Most of the skill is keeping the sauce in that narrow band. Vinaigrette is the other extreme: a temporary emulsion with too little emulsifier to hold for long, so you shake it again just before serving.
What you need
- Balloon whisk: A large, springy whisk breaks oil into small droplets far faster than a fork or a stiff sauce whisk.
- Heavy bowl and a damp tea towel: Twist the towel into a ring and sit the bowl in it so it stays put while one hand whisks and the other pours.
- Stick blender and a tall jar: A jar only a little wider than the blender head makes mayonnaise in under a minute.
- Jug with a spout: For pouring oil or melted butter in a thin, controllable stream.
- Saucepan and heatproof bowl: A makeshift bain-marie for hollandaise; the bowl should sit above the water, not in it.
- Instant-read thermometer: Takes the guesswork out of warm yolk sauces until you can judge them by eye.
- Jam jar with a lid: The easiest way to make, store and re-shake vinaigrette.
Step by step
Start mayonnaise with everything at room temperature
Put 1 yolk, 1 teaspoon of Dijon mustard, a pinch of salt and 1 teaspoon of lemon juice or vinegar in the bowl and whisk for 20 seconds. Measure out 200–250 ml of oil. Cold yolks and cold oil emulsify more reluctantly, so take the egg out of the fridge 30 minutes ahead.
Tip: Salt and acid dissolved in the yolk at the start season the sauce evenly and help it thicken.
Add the oil drop by drop, then in a stream
Whisking constantly, add the oil a few drops at a time until the mixture thickens and turns pale, usually after the first 3–4 tablespoons. Then pour in a thin, steady stream, whisking all the while. If it gets very stiff, loosen it with a teaspoon of water or lemon juice before adding more oil.
Tip: Watch the surface. If you see a ring of unabsorbed oil, stop pouring and whisk until it disappears.
Or use a stick blender
Put 1 whole egg, 1 teaspoon of mustard, 1 tablespoon of lemon juice and a pinch of salt in a tall jar, then pour 250 ml of neutral oil on top. Let it settle for a few seconds, push the blender to the bottom, switch on and hold it there until thick mayonnaise forms around the head. Then slowly lift it to draw in the rest of the oil. The white makes a softer, lighter sauce than yolk alone.
Tip: Blend only neutral oil. Whisk any extra virgin olive oil in by hand afterwards.
Season and finish
Taste and adjust with more salt and acid; mayonnaise usually needs more of both than you expect, because fat dulls flavour. Thin it with a little water for a dressing consistency. Cover the surface and chill.
Make a hollandaise base over gentle heat
Melt 250 g of butter and keep it warm. In a heatproof bowl whisk 3 yolks with 2 tablespoons of water and a squeeze of lemon. Set the bowl over a pan of barely simmering water and whisk until the yolks are thick, pale and hold a trail, about 3–5 minutes. Lift the bowl off the heat whenever it feels hot; the yolks must stay below about 70 °C or they start to scramble.
Tip: If the bowl is too hot to hold comfortably against the back of your hand, it is getting too hot for the yolks.
Whisk in the butter gradually
Off the heat, add the warm butter a spoonful at a time at first, then in a thin stream, whisking all the time. Clarified butter makes a thicker, more stable sauce; whole melted butter gives a lighter one with more flavour, as long as you leave most of the milky sediment behind. Season with salt, lemon and a pinch of cayenne.
Tip: Blender method: put the yolks, water and lemon in a blender, then pour in hot, just-bubbling butter in a thin stream with the motor running. The heat of the butter cooks the yolks. It takes 2 minutes and rarely fails.
Turn it into béarnaise
Simmer 4 tablespoons of white wine vinegar, 4 tablespoons of white wine, a finely chopped shallot, a few crushed peppercorns and some tarragon stalks until only about 2 tablespoons remain. Strain, cool slightly and use this reduction in place of the water and lemon in the hollandaise. Finish with plenty of chopped tarragon, and a little chervil if you have it.
Hold warm sauces warm, never hot
Keep hollandaise or béarnaise in a warmed thermos, or in a bowl set over a pan of hand-hot water off the heat. Around 60 °C is ideal. Hotter and it splits; cooler and the butter sets and the sauce turns stiff. Whisk it now and then.
Shake a vinaigrette
Put 1 tablespoon of vinegar or lemon juice, 1/2 teaspoon of Dijon mustard and a pinch of salt in a jar and shake until the salt dissolves. Add 3 tablespoons of oil, put the lid on and shake hard for 15 seconds. Taste on a leaf of the salad, not from a spoon, and adjust.
Tip: Salt dissolves in vinegar but barely at all in oil, so always add it before the oil.
The sauces at a glance
| Sauce | Base ratio | Emulsifier | Temperature | Keeps |
|---|
| Mayonnaise | 1 yolk : 200–250 ml oil, plus 1–2 tsp acid | Yolk, mustard | Room temperature to make, then chilled | 1–2 days, refrigerated |
| Aioli | 1 yolk : 200 ml oil : 2–3 garlic cloves | Yolk, crushed garlic | Room temperature to make, then chilled | 1 day, refrigerated |
| Hollandaise | 1 yolk : 75–85 g butter, plus lemon | Yolk | Yolks below 70 °C; hold at about 60 °C | 1–2 hours warm |
| Béarnaise | As hollandaise, with a tarragon-shallot reduction | Yolk | Yolks below 70 °C; hold at about 60 °C | 1–2 hours warm |
| Beurre blanc | 2–3 tbsp reduction : 200–250 g cold butter | Milk proteins in the butter | Hold at about 50–60 °C | About 1 hour warm |
| Vinaigrette | 3 parts oil : 1 part acid | Mustard (briefly) | Room temperature | A week refrigerated; 2–3 days with fresh shallot or garlic |
How to rescue a split sauce
| Sauce | What happened | Rescue |
|---|
| Mayonnaise or aioli | Oil added too fast, or too much oil for the yolk | Put a fresh yolk, or 1 tsp mustard with 1 tsp water, in a clean bowl. Whisk in the split sauce drop by drop, then in a stream. |
| Hollandaise or béarnaise, greasy and split | Too hot, or butter added too fast | Off the heat, whisk 1 tbsp cold water into a clean bowl and add the sauce slowly. If it was only slightly too hot, an ice cube whisked straight in can be enough. |
| Hollandaise or béarnaise, stiff and split | Too cold, so the butter set | Whisk in 1 tbsp hot water and warm very gently over the bain-marie. |
| Hollandaise, grainy or scrambled | Yolks overheated | Lightly grainy: whisk in a little cold water and push through a fine sieve. Properly scrambled: start again with a new yolk and treat the sauce as the butter. |
| Beurre blanc | Too hot, so the butterfat separated | Off the heat, whisk a cube of cold butter or a spoonful of cold cream into a clean pan and whisk the sauce back in slowly. |
| Vinaigrette | Normal separation | Shake or whisk again just before dressing. A little more mustard holds it longer. |
Troubleshooting
My mayonnaise won't thicken
The oil went in too fast at the start, before enough droplets had formed, or the ingredients were very cold. Do not keep adding oil in the hope it catches. Treat it as split: start again with a fresh yolk and whisk the thin mixture in slowly.
My mayonnaise was thick and then suddenly split
Usually too much oil for the yolk, or the sauce became so stiff the droplets were squeezed together until they merged. Add a teaspoon of water or lemon juice whenever it gets very thick. Once it has split, rebuild it on a fresh yolk or a spoon of mustard.
My hollandaise is grainy or has bits of cooked egg
The yolks went past about 70 °C. Lift the bowl off the heat more often and keep the water at a bare simmer, with the bowl clear of it. Small grains can be sieved out; heavily scrambled yolks need a fresh start.
My hollandaise turned greasy and thin
It has split, either from too much heat or from adding the butter faster than the yolks could take it. Pull it off the heat at once and rescue it with a spoon of cold water in a clean bowl. Next time pour slower and keep the butter warm rather than sizzling.
The sauce is too thick
Whisk in water, a few drops at a time: warm water for hollandaise and béarnaise, cold for mayonnaise. Lemon juice works too, but it also changes the seasoning. A very stiff emulsion is close to splitting, so loosen it before you add more fat.
My vinaigrette separates in seconds
That is normal; there is too little emulsifier in a vinaigrette for it to stay together. Add a little more mustard, a teaspoon of honey or a spoon of mayonnaise to slow it down, and shake it again right before dressing the leaves.
My olive oil mayonnaise tastes bitter
High-speed blending scatters the bitter polyphenols in strong extra virgin olive oil through the sauce. Make the base with neutral oil and whisk in the olive oil by hand at the end, or use a milder olive oil.
Raw and lightly cooked eggs
Mayonnaise and aioli use raw egg, and hollandaise yolks never get hot enough to be reliably pasteurised. Lemon juice and vinegar do not make them safe.
- Use the freshest eggs you can get, with clean, uncracked shells.
- Keep mayonnaise and aioli refrigerated and use them within a day or two. Do not leave them out on a warm table for hours.
- For pregnant, elderly, very young or immunocompromised guests, use pasteurised eggs, or a pasteurised liquid yolk, which emulsifies just as well.
- Hold hollandaise, béarnaise and beurre blanc warm for no more than about 1–2 hours, then throw them away. Do not reheat or keep leftovers.
- Raw garlic in oil should be kept cold and used quickly, so treat aioli as a same-day or next-day sauce.
