Butter sauces may add a layer of flavor to a dish, but throw in an egg or two and you have a sauce that is thicker, richer, and creamier. The melt-in-your-mouth goodness of a Hollandaise sauce over Eggs Benedict or a Béarnaise sauce over a steaming serving of asparagus can be attributed to the emulsification properties of the egg yolk. The protein in the egg yolk makes the water around the butterfat more viscous, generating that soulful feeling of fulfillment as your taste buds meet the sauce.
While the love of a good Hollandaise or Béarnaise may be unabashed, the egg and butter sauce reciprocates with fickleness. Heat and butter, which work with the egg yolk to produce such thick creaminess, are also the wicked villains that can cause the most coddled sauces to curdle. According to Harold McGee, the unparalleled expert in food science for everyday kitchens, the water content of regular butter can thin the sauce, while clarified butter (in which water has been removed) will dramatically thicken the sauce.
Heat plays an even trickier role. In order to thicken the sauce, egg yolks must be heated. But with too much heat (160°-170°F or 70-77°C), the yolks will coagulate and the butter will separate from the sauce.
According to McGee, there are five methods of making a Hollandaise or Béarnaise sauce:
- Start by cooking the eggs and water-based ingredients, then whisk in pats of butter for emulsification and thinning. The drawback? It’s easy to overcook the egg.
- Warm the eggs and water-based ingredients, whisk in butter (either regular or clarified), and then cook. This method makes it easier to control the thickness of the sauce.
- Slowly heat all of the ingredients together. The egg and butter heat at the same time, and give you control over the consistency (plus, it’s easy!).
- Warm – but don’t cook – the egg yolks so that they’re slightly warmer than the point at which butter melts, and then whisk in clarified butter. The result? A butter mayonnaise.
- While heating, whisk egg yolks and water into a foam, and then add melted or clarified butter and an acid reduction. This results in a lighter sauce.
Help grow this exhibit! Join in the fun by sending your favorite tips for cooking with butter, or your tried-and-true recipes. Read more about sharing your tips and recipes.