What was the bad recipe? There's only three or four ingredients in mayonnaise and you kind of have to eyeball the proportions. It's been made for a long time, so power tools are not necessary.
It's a simple emulsion of oil and egg yolks with mustard and vinegar for flavor, and other things if you like:
INGREDIENTS:
* 2 egg yolks
* 3/4 teaspoon salt
* 1/2 teaspoon powdered mustard
* 1/8 teaspoon sugar
* Pinch cayenne pepper
* 4 to 5 teaspoons lemon juice or white vinegar
* 1-1/2 cups olive or other salad oil
* 4 teaspoons hot water
PREPARATION:
Beat yolks, salt, mustard, sugar, pepper, and 1 teaspoon lemon juice in a small bowl until very thick and pale yellow. (Note: If using electric mixer, beat at medium speed.) Add about 1/4 cup oil, drop by drop, beating vigorously all the while. Beat in 1 teaspoon each lemon juice and hot water. Add another 1/4 cup oil, a few drops at a time, beating vigorously all the while. Beat in another teaspoon each lemon juice and water. Add 1/2 cup oil in a very fine steady stream, beating constantly, then mix in remaining lemon juice and water; slowly beat in remaining oil. If you like, thin mayonnaise with a little additional hot water. Cover and refrigerate until needed. Do not keep longer than 1 week.