Place egg yolks in a small saucepan. The whites can be saved for a different recipe.
Add the water and lemon juice to the yolks in saucepan and whisk the until smooth.
Dice the cold butter into small pieces and add them to the yolk mixture.
Place the saucepan over medium-low heat and continuously whisk as the egg mixture heats. The butter will begin to melt and the sauce will begin to froth. As it continues to cook, the mixture will thicken. Continue to whisk continuously until a light, smooth sauce with the consistency of gravy emerges.
Remove from the heat, season with salt and a pinch of cayenne to taste. Drizzle over eggs benedict, salmon, or your favorite food.
Notes
Tip:Use low heat. Hollandaise sauce cooks best over gentle heat. If the pan becomes too hot, remove it briefly from the burner while whisking to prevent the eggs from scrambling.
Tip: Whisk constantly. Continuous whisking helps create a smooth emulsion between the egg yolks and butter.
Butter cubes. Cutting the butter into small cubes helps it melt gradually and incorporate smoothly into the sauce.
Thickness. If the sauce becomes too thick, whisk in 1–2 teaspoons of warm water until it reaches the desired consistency.
Season to taste. After adding the lemon juice, taste the sauce and adjust with salt, additional lemon juice, or a pinch of cayenne or white pepper.
Serving temperature. Hollandaise is best served warm immediately after making. If needed, keep it warm for up to 30 minutes by placing the saucepan over a bowl of warm (not hot) water.
Reheating. Reheat very gently over low heat while whisking constantly. Add a teaspoon of warm water if needed to loosen the sauce.