The following is how i was taught to make Bernaise sauce.
ingredients:
1C white wine
1C white wine vinegar
1 diced shallot
1tsp diced fresh tarragon
2C unsalted butter
4 egg yolks
cayenne
salt
pepper
In a sauce pan pour white wine and white wine vinegar. Add the diced shallot and fresh tarragon.
Bring to just below boiling and cook down till there is no liquid left. Add the egg yolks and whisk vigorously till mixed.
Once the egg yolks start to firm, to the point where the are beginning to become a touch viscous, begin adding the butter.
The key here is to balance the heat from the stove with the addition of the butter. I like to use room temperature butter
cut into slices so i can control the rate of addition, and so that the butter isn't so cold as to shock the sauce into breaking.
A good indicator of the proper viscosity is when, while whisking, one can easily see the bottom of the pan between strokes.
When the desired consistency is reached it should be seasoned (salt, pepper, cayenne) according to taste.
The salt content should be just enough to bring out the sweet quality in the butter. The cayenne should be relatively minimal
just enough to add a hint of spice to the sauce. Not enough that it becomes overly noticeable, or spicy for that matter.
While making this sauce it is vital that unsalted butter be used so that the flavor can be more precisely controlled. From the addition of the eggs till all
the butter is mixed in completely one should never stop stirring. Pay very close attention while adding the butter. To much to fast may break the sauce, and
adding the butter to slowly while your pan is over the heat will over cook and curdle your egg. Pay very close attention while cooking. Heat management and whisk speed are your best
allies in making this sauce.
If while cooking the sauce and one notices a distinct separation of egg matter and butter (a clear liquid separating form the thicker yellow)
this means that your sauce is "breaking" immediately remove your pan from the heat source, and begin whisking as fast as you can. If necessary splash with a little bit of cold water. By splash i mean
run your hand slightly cupped through a stream from your faucet and toss that into the pan.
This sauce is excellent for steak, or grilled asparagus.