Using clarified butter will prevent the curdling of hollandaise sauce. I make mine by melting the butter, adding the lemon juice, salt, and pepper to the butter. Whisk the mixture. Whisk the yolks. Temper the yolks by adding a small amount (1 tbsp) of the hot butter to the yolks. Whisk. Repeat this addition of the hot butter into the yolks 4x. Then, simply pour the yolk mixture into the butter, whisking continuously. Done. Do not cook it at all.