I did not expect an immersion blender to become a kitchen essential for me, but that’s where I am now. I originally thought it’d be great for making milkshakes, but then I figured out water-in-oil emulsions, and realized that homemade mayonnaise is a million times better¹ than what comes in the jar.

Summarizing: the immersion blender turns the very technical and tedious process of emulsification into something that is so simple I got it right the first time, and haven’t failed at it yet. Here, then, is a very basic recipe for homemade mayo:

Basic Homemade Mayonnaise

Ingredients

• 1 egg
• 1 tablespoon vinegar
• 1 tablespoon lemon juice
• 1/4 teaspoon salt
• 1/8 teaspoon mustard
• 1 cup avocado oil

Equipment

• An immersion blender with its own blending cup
• Measuring spoons & measuring cup
• A fridge-friendly container for the finished product

Instructions

1. Put everything except the oil in the blender cup.
2. Gently pour the oil atop the other stuff, and then wait a moment for things to separate. It’s very important for the oil to be on top.
3. Gently sink the blender head to the bottom of the cup, positioning it like a dome over the egg, tipping it on the way down to get the air out.
4. Blend at high speed, keeping the blender head at the bottom of the cup. Slowly lift it, and allow yourself to be amazed as it makes your mixture into mayo on the way up.
5. That’s it! Scrape it into a container and put it in the refrigerator. It’ll keep for about a week

You may be asking if you can use something other than avocado oil. You can, but I recommend starting with avocado oil because I want your first batch of mayo to taste good. Olive oil will, for organic chemistry reasons I don’t fully understand, respond poorly to the emulsion process, giving the mayo a flavor I describe as “sawdust adjacent.”

You may also be asking how this even works. Traditionally, mayonnaise is made by vigorously whisking the eggs and the watery stuff while slowly adding oil. Adding the oil too quickly will cause things to fail, and the failure mode of mayonnaise is that it separates, and the oil floats back to the top. The immersion blender, coupled with its special made-to-fit cup, solves this problem by drawing the oil down into the blend. This is why you start at the bottom and gradually lift. You’re “slowly adding oil” by slowly giving the blender head traction on the oil above it.

Emulsification is Magic

Emulsification is when two immiscible (“not mixable”) liquids get mixed with the help of something else. In the case of mayonnaise you are mixing water and oil by giving the tiny droplets of watery ingredients (the vinegar and the lemon juice) a nice coating of egg proteins.

Fun fact! Butter is also a water-in-oil emulsification. By weight it’s about 80% milk fat (cream), 20% water, and maybe a couple of percentage points of milk proteins, sugars, and “bad at math.” This may seem like useless information, but if you’re looking for a dairy-free recipe substitute for butter, you can substitute almost any other water-in-oil emulsification. The tl;dr— Yes, you can use mayo instead of butter in recipes.

Cow-milk products are pretty complex things. There is a LOT going un under (udder?) the hood, and I’ve found that the best way to swap out a milk product is to swap in something similarly complex. Mayo can be pretty bland (it is literally used in comedy routines as a stand-in for “so bland”) but if you increase the complexity a bit it’ll do just fine as a stand-in for butter.

Sandra is allergic to dairy, mustard, wheat, and yeast, but she loves Hollandaise sauce on Eggs Benedict—a dish which, if prepared traditionally, is the Yahtzee in the game of “Sandra can’t eat this.” We prepare it non-traditionally by taking a nice Hollandaise recipe and swapping out the butter for homemade no-mustard mayo. Then we serve the sauce and the eggs on a bed of wild rice, which, if I’m being completely honest, is a healthier and tastier option than an English muffin.

Dairy-Free Hollandaise

Ingredients

• 5 egg yolks (set aside or discard the egg whites²)
• 2 tablespoons champagne vinegar
• 1/4 cup water
• 1 tablespoon lemon juice
• 2 teaspoons finely minced shallots
• 1/2 cup homemade no-mustard mayo
  • OR sure you can just use a stick of softened butter instead of the mayo, but then it’s not dairy-free, obviously.

Equipment

• Immersion blender & blender cup
• Measuring spoons and cups
• Knife & board for mincing the shallots
• 1 pint canning jar with ring and lid
• A small hand-whisk or maybe just a fork that will fit into that canning jar
• Sous vide bath, because let’s do this the easy way

Instructions

1. Separate the eggs, and put the yolks in the blender cup. What you do with the egg whites is your business², but they don’t go in your Hollandaise sauce.
2. Add the vinegar, lemon juice, salt, and minced shallots. Don’t be lazy and expect the immersion blender to mince the shallots for you. It’s not a food processor. Cut them up fine using your knife!
3. Add the homemade mayo.
4. Blend with the immersion blender. You’re not trying to emulsify, so just blend away. The mix should end up yellow and a little runny.
5. Pour the pre-Hollandaise into the pint jar, and put the lid on loosely.
6. Put the jar into the sous vide. The water level should be below the lid, but above the level of the stuff in the jar.
7. Run the sous vide at 160°F for 90 minutes.
   —90 minutes later…
8. Remove the jar (carefully, it’ll be hot) and remove the lid. Whisk the contents vigorously, then (and I cannot stress this enough) shove that whisk into your mouth and slurp the delicious Hollandaise from it. Then put it into the sink, NOT back into the jar. No, not even if you live alone.
9. Lid the jar and put it into the fridge. It should keep for at least a week, assuming your whisk was clean.

When the time comes to serve the sauce, it’ll work well cold on sandwiches, or you can microwave a little bit of it for Eggs Benedict.

The Plot Thickens, AKA “I See What You Did There”

19th-century French chef Antonin Carême famously declared (in a book that got lots of traction) that there are five sauces mères or “Mother Sauces”: Espagnole, Velouté, Béchamel, Tomate, and Hollandaise. All other sauces are sauces petit, variations on the basics.

Of Carême’s five mother sauces, four are thickened with roux (butter and flour)³, while the fifth is a water-in-oil emulsion. My inner taxonomist screams, because that’s really just TWO basic sauces, so maybe the system should have been sauces mère et père, or just “saucy parents⁴.”

The point here is that an ultra-simplified water-in-oil emulsion is literally THE MOTHER OF ALL MAYONNAISE⁵.

Let me restate this more usefully: once you reduce water-in-oil emulsification to water, oil, and a binding agent, you can make any emulsified sauce you want to. In mayonnaise, the vinegar and lemon juice are “water,” the avocado oil is (SURPRISE!) “oil”, and the egg is the binding agent. The salt and mustard are irrelevant to the emulsification (provided you don’t add so much that they become relevant.)

You can make flavored mayo by messing around in the “irrelevant” column. Mother said it’s okay, really! For instance, you can make a nice Southwest seafood taco sauce by replacing the lemon and the vinegar with lime juice, using a dash of Cholula instead of mustard, and throwing in some cilantro. Did you want “spicy mayo” for sushi? Use rice vinegar and maybe two tablespoons of Sriracha instead of lemon juice, then toss in some minced ginger. As long as the general ratio of “watery” to “oily” stays the same, your mixture will emulsify deliciously.

Metrics For Science

The measurements in my recipes are all Imperial, which is problematic for two reasons:

1. Imperial. Ugh.
2. Milliliters are better than rounding to fractions of cups and spoons.

I’d switch to metric, but that would mean buying a bunch of kitchen stuff and learning new things, so it’s a project for a more ambitious day. Still, I recognize that if you really want to get fancy with your oil-in-water emulsifications, you’ll find that the metric system provides more consistent (especially with regards to the consistency of the sauce, hah!) results.

I’ve found a workaround, though, and that’s by using the lines on the immersion blender cup. My watery ingredients for a proven emulsion come halfway up to the 3-ounce line. The egg takes me up to the 3 ounce line, and I’m using 8 ounces of oil. This means my ratio of water to emulsifier to oil is 1.5 : 1.5 : 8. When I start messing around with other ingredients, I keep that ratio in mind, and use the lines on the blender cup to help me get the ratio correct. I also use it to keep track of what I did in case I need to change things on the next pass.

Would metric measurements be better? YES THEY WOULD please leave off with the pestering of the cartoonist and go update all the gear in your own dang kitchen.

But start by getting an immersion blender, because homemade mayo is, as I stated at the top of this essay, a million times better¹ than what comes out of a store-bought jar.

— notes —

¹ “A million times better” is sloppy math, but that didn’t stop me from using it twice. Fine. Let’s instead say that homemade mayonnaise is the thing casting the mayo-from-a-jar shadow on the wall of Plato’s Cave & Delicatessen.

² Now that you know how to make The Mother of All Mayo, those egg whites might be the elemental emulsifier for some (sorry-not-sorry) very saucy experimentation. You could also use them for an egg-white omelette, or perhaps a nice meringue.

³ Since roux is butter and flour, and butter is a water-in-oil emulsion, it should be possible to make a no-dairy/no-wheat roux using mayonnaise and corn starch and why are you looking at me like that?

⁴ My taxonomical howling is about a hundred and fifty years too late to get this bit of wordplay into all the best cookbooks. And even if I could yell back in time I’d be yelling in English, and I’m not a chef, so I don’t think Carême would listen to me.

⁵ Water-in-oil emulsion is also the mother of butter, and the mother of a long list of non-edible things, including industrial lubricants and hand lotions… although I suppose you could make your own hand lotion from edible ingredients and this is why I am not and never should be a chef.