Mayonnaise is an emulsified sauce. That means that the little drops of fat (from the oil) get suspended in the mayonnaise base (the vinegar or lemon juice, mustard, and sometimes water) to ultimately make a smooth, thick mixture. Rather than remembering a detailed recipe, what you really need to remember is the ratio of egg yolks to oil. I know that ratios are math and math is hard, but I have to admit that they’re pretty useful in the kitchen. Basically, for certain mixtures, sauces, and syrups, if you know the basic ratio of ingredients, you can make as much as you need without ever consulting a recipe. I talked a little about ratios on the “How to make simple syrup” page – the ratio for simple syrup was 1:1. The ratio for making your own mayo is a little harder to remember, but still fairly simple: 1 egg yolk to 150 ml (a little less than 3/4 cup) oil. If you want to double the recipe: 2 egg yolks to 300 ml oil. And so on.
You can use homemade mayonnaise just like you’d use commercial mayo, although it does have a slightly different flavor. I like to use it to make everyday dishes extra-special – think chicken salad with homemade mayonnaise. If your mayo is a little thick, just beat a teaspoon or more of water into it until it reaches your desired consistency. Note that homemade mayonnaise contains raw eggs, so you might not want to serve this to small children, the elderly, or people with compromised immune systems because of the risk of salmonella. Use high quality eggs and oil for the best flavor. If you want to use extra virgin olive oil, use about a 1:4 ratio (!) of extra virgin olive oil to a more neutral-flavored oil (grape seed, canola) to avoid bitterness.
1 egg yolk
1 tablespoon Dijon mustard
1 teaspoon high-quality vinegar (I used champagne wine vinegar) or lemon juice
A good grinding of black pepper
150 ml oil (I used part grape seed oil, part extra virgin olive oil)
1. Combine the egg yolk, mustard, vinegar or lemon juice, salt, and pepper in a medium stainless bowl and whisk for a few seconds to combine.
2. Very slowly pour in the oil, drop by drop, whisking constantly. You’ll start to see the mixture thicken, become homogeneous, and lighten in color.
3. After the mixture thickens a bit, you can drizzle in the rest of the oil in a thin stream, whisking constantly.
4. Keep whisking.
5. Thin the mayo with a teaspoon or so of water if it is too thick. Taste and correct for seasoning.