While possible, making hollandaise sauce in a microwave or directly over heat is not recommended due to the high risk of curdling. A double boiler or immersion blender method offers more control and a smoother result.
Hollandaise sauce is an emulsion of egg yolks, melted butter, and lemon juice (or vinegar). The key to a successful hollandaise is gentle, even heat. Direct heat, whether from a stovetop burner or a microwave, can easily overheat the egg yolks, causing them to scramble and the sauce to break (curdle).
Why a Double Boiler is Better: A double boiler provides indirect heat, gently warming the egg yolks and allowing them to thicken without the risk of scorching. The steam from the simmering water below heats the bowl above, creating a more controlled environment.
Why an Immersion Blender Works: An immersion blender emulsifies the ingredients quickly and efficiently. The constant motion helps to prevent the egg yolks from overheating and curdling. This method is faster and often more reliable than the traditional double boiler.
Microwave Method (Use with Caution): If you must use a microwave, proceed with extreme caution. Microwave in very short bursts (5-10 seconds) at low power, whisking vigorously between each burst. The risk of curdling is very high.
Direct Heat Method (Not Recommended): Cooking hollandaise directly in a saucepan over a burner is the most challenging method. It requires constant whisking and precise temperature control. Even with experience, the risk of curdling is significant.
If your hollandaise sauce curdles, try whisking in a tablespoon of ice water. The sudden temperature change can sometimes bring the emulsion back together.