Mayo is an emulsion of oil which is tiny oil droplets suspended in some other kind of liquid, usually an acidic one like lemon juice or vinegar. Lecithin found in egg yolks and mustard help to chemically stabilize the emulsion. Air incorporated into the mix makes it light and creamy.
CAUTION: Use of kitchen appliances with blades that spin in excess of 2 billion rpms is dangerous. Know what you are doing in the kitchen and clean up the mess afterwards.
Step 1: A few things from the pantry...
Juice of half a lemon
A squirt of mustard
An egg yolk, use the egg white in another recipe
Oil, the usual bland vegetable oil
Salt and pepper
And for the added zip, you can add:
minced clove of garlic
minced leafy herbs like parsley, choose a good herb to pair with the food the mayo will be used on
Note that I don't usually measure anything when I cook. Get a feel for what works.
Step 2: Get in the mix...
Put a squirt of mustard in there.
Squeeze a bit of lemon juice in there also.
You can add some salt and pepper too.
Add a bit of oil.
Start to whisk together. The mix should start clouding up and you should see it get a bit thicker or lumpier. This is the start of the emulsification process.
Add more oil as you whisk. Get it to a consistency of a runny mayo.
Step 3: Round and round it goes...
Well, like Forrest Gump, after about ten minutes I just got tired of whisking and stopped whisking.
It did seem to get a bit thicker but it was still too runny. I added some more oil to see if that would lighten it up and add to the volume.
I guess there are legends of some chefs being able to make mayonnaise by hand but it is largely an invention of the industrial age.
I transferred the contents to my blender machine.
After a few minutes of high speed blend, it was looking like real mayo.
Step 4: Flavorize it...
add the chopped garlic and herbs.
Process for a few more minutes until all is well incorporated. Maybe add another egg yolk?
It seems to work as seen on TV.
Put in the fridge to set up some more.
Use on meats, sandwiches, salads or mix in with tuna fish.
Use fresh mayonnaise promptly since it does contain raw egg. Do not confuse this with other science experiments in the back of the fridge.