In blender whirl yolks until just blended.
Add reduced wine mixture and blend briefly.
Add melted butter,a droplet at a time,blending continuously on high speed.
As mixture thickens,increase butter to a thin stream.
Keep sauce warm by placing blender container in a pan of lukewarm water,if desired.
Note: for a faster Hollandaise version,simply omit first 7 ingredients and the first step.Proceed as directed.Makes 1/2 cup.