Why It Works
- By using a jar just wider than the head of the blender, the oil is gradually emulsified into the other ingredients.
- The oil floats at the top, so when you 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.
- The immersion blender creates a vortex, gradually pulling the oil down into the whirling blades.
If you've been reading the site for a few years, or have my book, you've no doubt read about this technique. You may have even seen this suuuuuuper-old video I made. 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 hope 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 infomercial for a hand blender (which, at the time—this was the mid-'80s—was remarkably new), I'd always assumed it came from.... Heck, I had no idea. Perhaps a big siphon somewhere out in the Midwest.
If you've only ever known mayonnaise in the form of the quivering, jelly-ish stuff that comes in the jar with the blue lid, you're doing yourself a disservice. 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'll 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, and mucilage, a slimy substance found in mustard and other plants), separated by water. Emulsifiers are unique in that one end of them is attracted to fats, while the other is attracted to water. When they bury their fat-loving heads into the minuscule droplets of oil, their water-loving tails are exposed, allowing 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, 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 with a broken, greasy, curdled-looking mess instead of the smooth, rich, creamy sauce of your dreams. About half the time I try to make mayonnaise with this method, it breaks, and I'm forced to start over.
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—the 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 amount 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. A blender or food processor gets me up to about 85% success.
The easy solution? Use an immersion blender. With an immersion 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 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'll create 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 use a Microplane to grate one clove per egg yolk into the mix.) For the record, I also ditch the water and simply use whole eggs instead of egg yolks. Egg whites are mostly water anyway, and I haven't noticed any appreciable difference between mayo made with whole eggs and mayo made with yolks plus water. In fact, Stella and Daniel have ditched yolks altogether in some recent experiments, a feat I can't fully wrap my head around yet.
Troubleshooting: What If My Mayo Doesn't Work?
UPDATE: So I called this "foolproof," but really, it ought to be called "fool-resistant," because even the most bulletproof technique fails now and again. Some people have reported that the mayonnaise never comes together when blending. The number one problem I've discovered is using the wrong-sized vessel. It is imperative that the vessel be just slightly larger than the head of the immersion blender, as the egg/lemon mixture must be in contact with the blades of the blender before you switch it on for this to work. The head of the blender must be firmly planted against the bottom of the jar until the mayonnaise starts to come together. If you can't find a jar the right size, the other option is to double the recipe in order to increase the starting volume of the egg/lemon mixture.
Finally, if your mayonnaise is watery, that means it has not emulsified properly, and no amount of additional blending is going to fix that. Your best bet is to let the mixture settle and separate, then try again.
Pro Tip: Be Careful With Your Extra-Virgin Oil
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 flavor. Not only that, but these tiny fragments actually decrease the efficacy of emulsifiers like mustard and lecithin, making your sauce more likely to break.
So, what if you want 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.
1 large egg
1 tablespoon (15ml) lemon juice (from 1/2 a lemon)
1 teaspoon Dijon mustard
1 medium clove garlic, minced
1 cup (240ml) vegetable or canola oil
1/4 tsp Kosher salt
Place egg, lemon juice, and mustard in the bottom of cup or jar that just fits the head of your immersion blender. The egg/lemon juice mixture must reach the blades for this to work (see note). If the mixture does not reach the blades, double the recipe before attempting.
Add garlic, if using. Pour oil on top and allow to settle for 15 seconds. Place head of immersion blender at bottom of cup and turn it on high speed. Do not pulse or move the head. As mayonnaise forms, slowly tilt and lift the head of the immersion blender until all oil is emulsified. Season mayonnaise to taste with salt. Store in a sealed container in the refrigerator for up to two weeks.
It is imperative that the jar you use be just slightly larger than the head of the immersion blender, and the egg/lemon mixture must be in contact with the blades of the blender before you switch it on for this to work. The head of the blender must be firmly planted against the bottom of the jar until the mayonnaise starts to come together. If you can't find a jar the right size, double the recipe in order to increase the starting volume of the egg/lemon mixture.
If your mayonnaise is watery, that means it has not emulsified properly. Let the mixture settle and separate, then try blending again.