Whip some egg whites until stiff – light and fluffy as a cloud. Then add a few drops of oil, whip a bit more, and the whole thing goes creamy, fluffy no more. How come?
Scientificy explanations appreciated, with or without “stiff” jokes. Cream of tartar comments also welcome.
Oil is an emulsifier, the chemical properties allow it to bond with most other items, making it thick and creamy.
Magnificent to behold - Greatly to be praised.
The yolk is an oil too, and any of it in the whites will cause the above problem.
Sorry if I’m being dense. But: ok, the oil bonds with the egg white. So why, exactly, does this cause the already-whipped egg whites to become unable to hold the air that was trapped within them? (This probably requires some understanding of why egg whites can be whipped stiff in the first place, which I obviously don’t have.)
Also, egg yolk is an oil? Huh?
Ever try rubbing your finger on your nose to take the head off a beer or seen the Phazyme commercials? That’s why. 
Also, egg yolks aren’t oil, they are an emulsifier.
“I would far rather be ignorant than wise in the foreboding of evil.”
-Æschylus. 525-456 B. C.
Whip those egg yolks with olive oil and you’ve got a lovely mayonnaise.
[Julia Child voice] Bon appetit! [/Julia Child voice]
Leslie Irish Evans
http://leslie.scrappy.net
whip the whole egg with oil, mustard, garlic and lemon juice and you get a delicious aoli! Perfect for sandwiches or garnish!
Magnificent to behold - Greatly to be praised.
Here in Catalonia we make all-i-oli with just egg yolk, garlic, and olive oil. Your recipe sounds tasty, though, though I think I’d leave out the egg white.