This week's Food Lab is all about brevity. Not only will I show you how to make mayonnaise at home in two minutes or less, but I'll also explain the entire process in precisely 1,110 words, (making this the briefest Food Lab post ever in its entire long-winded history), and perhaps convince you to buy a hand blender if you don't already have one.
There is nothing here that has not been done before by other people. But it explains one of the most oh-my-god-I-can't-believe-I-just-saw-that-happen moments I've had in my life, and I'm sharing it in the hopes that it might give at least a few of you a very similar reaction.
Up until the time I saw mayonnaise being made on a late-night full-length informercial for a hand blender (which at the time—this was the mid-80's—were remarkably new), I'd always assumed it came from... Heck, I had no idea. Perhaps a big siphon somewhere out in the midwest. The thought that it's made with egg yolks and oil certainly never crossed my mind.
If you've only ever known mayonnaise in the form of the quivering jellyish stuff that comes in the jars with the blue lid, you're doing yourself a disservice. Like switching from briefs to boxers or walking to Mordor, trying homemade mayonnaise is the kind of thing that will forever change your life (or at the very least, your sandwiches).
What Is Mayonnaise?
Mayonnaise is an emulsion of oil and water—two liquids that generally don't get along. Look at it under a microscope, and you'd see it's made up of teeny tiny fat droplets coated in a thin film of emulsifying agents (mainly in the form of lecithin, a protein found in egg yolks), separated by water. Emulsifiers have the unique property that one end of them is attracted to fats, while the other is attracted to water. By burying their fat-loving heads into the minuscule droplets of oil, their water-loving tails are exposed, allowing both the fat and the water to coexist peacefully.
Because you are attempting to combine two ingredients that really don't want to be combined, Mayonnaise is notoriously difficult to make. Classic technique will have you start by whisking egg yolks, a bit of mustard (for flavor and its emulsifying properties), a few drops of water, and some acid (either lemon juice or vinegar), then slowly slowly slowly trickling in a thin stream of oil as you continue to beat rapidly. The idea is to get the oil to disperse itself into tiny droplets as you whisk it.
Pour the oil too fast, and you end up not with a smooth, rich, creamy sauce, but with a broken, greasy, curdled-looking mess. About half the time I try and make mayonnaise with this method, it breaks and I'm forced to start the process over again.
There are a number of techniques for making this process a bit more foolproof, with the blender or the food processor being the usual go-to's—their high-speed whirring blades make short work of dispersing oil droplets. The problem with either of these appliances, however, is that you need to make a fairly large volume of mayo for them to work—start with a single egg yolk, for example, and there's not enough volume in there to spin around properly. The egg flies up and splats against the walls, leaving you nothing to work with at the bottom of the jar/bowl.
They also still require you to drizzle in your oil ever-so-slowly. Blender/food processor gets me up to about 85% success.
The easy solution? Use a hand blender. With a hand blender you can add all of your ingredients—oil included—directly to the blending cup. Because it is less dense than the other ingredients, the oil will float at the top. When you subsequently stick the blades of the hand blender down into the cup, they'll be in direct contact with the egg yolk, water, acid, and mustard. Turn that blender on, and it creates a vortex, gradually pulling the oil down into the whirling blades.
Get it? It is essentially sucking down oil in a thin, steady stream, saving you from having to do it yourself. In no time flat, you end up with a cup full of creamy, perfectly emulsified, real-deal, better-than-anything-you-can-buy mayonnaise, and you've pushed yourself up to a 100% success rate (with the option of making small batches, to boot!).
Of course the best part of all this is that you get to flavor it however you'd like. Most often for me that means garlic (I microplane one clove into the mix per egg yolk I use).
Pro-tip: Be Careful With Your Extra Virgin
It's possible to make a truly tasty mayonnaise by using high quality extra-virgin olive oil, but there's a problem: Blenders, food processors, and hand blenders are too powerful.
You see, extra-virgin olive oil droplets are composed of many tiny fragments, many of which are bound tightly together, preventing our taste buds from picking them up. Whip the olive oil with enough vigor, by say, using a food processor or blender, and you end up shearing those bitter-tasting fragments apart from each other. The result is a mayonnaise with a markedly bitter taste. Not only that, but these tiny fragments actually decrease the efficacy of emulsifiers like mustard or lecithin, making your sauce more likely to break.
So what if you want to have an ultra-stable mayonnaise that's still strongly flavored with extra-virgin olive oil but has no bitterness? The key is to use a neutral-flavored oil like canola or vegetable to start your mayonnaise. Once it's stable, transfer it to a bowl and whisk in some extra-virgin olive oil by hand. You'll still get plenty of flavor, but none of the bitterness.
And this, my friends, is how great sandwiches start.
About the author: J. Kenji Lopez-Alt is the Managing Editor of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.