You won’t ever see mayo curdle; you’ll feel it. It will suddenly lose all its fight, and go slack, before turning to liquid. Don’t let this put you off, as it’s easily avoided, easily rectified, and, once you’ve had homemade mayo, there’s no going back. Yes, I know you can do this with a blender, but the washing up is more effort than whisking by hand. Yes, I know it’s properly called Aïoli, but not all my guests speak Foreign. Yes, I suppose you could make it without garlic but, frankly, what’s the point of being alive?
Assuming two greedy people, you’ll need one egg yolk, 150mL groundnut oil, 50mL of your best extra virgin, half a lemon, a pinch of salt, and a clove of garlic. You’ll also need a certain amount of sang-froid in case it all goes wrong, plus a spare egg.
Start by popping the yolk and the salt into a small round mixing bowl. Crush the garlic into this and give it a good thirty seconds with a balloon whisk. Doesn’t need to be furiously thrashed, just steadily mixed. This will seem pointless, but don’t worry. The mixture will lighten in colour; now leave it alone for a minute or two. It helps if your mixing bowl is heavy, resting on a rubber mat or, failing that, a slightly damp teatowel.
I find pouring directly from the oil bottle a bit awkward, so normally measure it out into a jug with a spout, to give me a little more control. Start with the groundnut oil, and have your half lemon ready.
Start whisking the yolk again, slowly, and feel how it’s slightly sticky, slightly resistant. From now on, keep on whisking. Slowly. Gently. Steadily. More of an andantino than an allegro furioso. Pour in a few drops of the oil. You’re aiming for a teaspoon or less, and keep whisking. Feel how the mixture momentarily loosens, then tightens again, as the oil is incorporated. Another teaspoon. That’s five millilitres. And again. And again; whisking all the time.
At this point you can start to think about adding larger quantities of oil (always less than a third of the volume you’ve already got in the mixing bowl) perhaps even consider a constant pour, in the thinnest stream your measuring jug permits. After around 50mL of oil, the mixture will start to become extremely sticky, and will threaten to attach itself to your whisk as an almost solid lump. Before that can happen, put the oil down, and give the half lemon a gentle squeeze to add a teaspoon of juice. Don’t stop whisking at any point. The mixture will loosen, and return to its prior stickiness. Keep adding oil, and a squirt of lemon juice each time the mixture becomes too thick.
Once all the groundnut oil is incorporated, you can stop for a quick rest, but once you’re ready, add the olive oil as before, again with a squirt of lemon juice to loosen. You may not need the entire half lemon.
Some recipes recommend more or less oil, but 200mL per egg yolk seems safe. Made using nothing but olive oil, it’s a little overwhelming, plus groundnut oil has the advantage of being cheaper. And when it goes wrong? Deploy the yolk of your spare egg into a clean bowl, start whisking, and gradually add the curdled mayo from the other bowl.
Serve it with steamed asparagus, new potatoes, baked fish, or as a dip for crusty white bread. It can be kept in the fridge for a day or two, assuming you have enough self control.