Hollandaise sauce can be a bit tricky if you try to reheat them. The sauce has butter, egg yolks, and lemon juice and they're prone to separate or becoming grainy when reheated too quickly or at too high a temperature. Here's the step-by-step to avoid them to separate.
- Transfer the hollandaise sauce to a small saucepan or heatproof bowl.
- Place the saucepan or bowl over a pot of barely simmering water (creating a double boiler).
- Stir the sauce gently and continuously as it heats up. This slow, gentle heating will help to re-emulsify the sauce without causing it to separate.
- Once the sauce reaches the desired temperature, remove it from the heat immediately and serve.
Avoid using a microwave to reheat hollandaise sauce, as it's more likely to cause the sauce to break or become grainy. Also, keep in mind that reheated hollandaise sauce may not have the exact same texture or consistency as freshly made sauce, but it should still be tasty.