Which ingredient is NOT part of the Hollandaise sauce recipe?

Hollandaise sauce is a classic emulsified sauce made primarily from egg yolks, melted butter, and an acid, typically lemon juice, which adds brightness and balance to the rich fat of the butter. The process involves whisking the egg yolks and combining them with the butter, ensuring that the sauce achieves a stable emulsion. The addition of lemon juice is essential for both flavor and stability.

Sugar, on the other hand, is not a component of the traditional Hollandaise sauce recipe. While sugar is used in many culinary contexts to balance flavors, it does not belong in this specific emulsion. The focus of Hollandaise is on the savory interaction of butter, yolk, and acidity, making it a distinctive sauce suitable for dishes like Eggs Benedict and various vegetables. Thus, the absence of sugar from the recipe is what distinguishes it as not being part of the Hollandaise sauce.