Equipment
Ingredients
Reduction Base
- 60 ml dry white wine
- 15 ml white wine vinegar
- 20 g shallot, finely minced
Tomato Base and Emulsion
- 15 g tomato paste
- 50 g fresh tomato, peeled, seeded, and finely diced (concassé)
- 150 g unsalted butter, extremely cold, cut into 1cm cubes
Seasoning and Herbs
- 3 g fresh tarragon, finely chopped
- 3 g fresh chives, finely minced
- sea salt
- white pepper
Nutrition (per serving)
Method
Finely mince the shallot, prepare the diced fresh tomato, and chop the tarragon and chives. Cube the unsalted butter and return it immediately to the refrigerator. The butter must remain completely solid until the exact moment of emulsification.
Combine the dry white wine, white wine vinegar, and minced shallot in a small heavy-bottomed saucepan. Bring to a gentle simmer over medium heat at approximately 90°C/194°F.
Allow the liquid to reduce until it is almost entirely evaporated, a state known as au sec. You should be left with about one tablespoon of thick, concentrated syrup glazing the shallots.
Lower the heat to low, around 45°C/113°F. Stir in the tomato paste and finely diced fresh tomato. Cook for one minute to temper the acidity of the paste and meld the flavors.
Begin whisking in the cold cubed butter, one or two pieces at a time. Whisk constantly, ensuring each addition is fully emulsified and completely melted before adding the next. Frequently pull the pan off the heat to regulate temperature; the sauce must not exceed 55°C/130°F or the emulsion will break and separate.
Remove the saucepan from the heat entirely. Gently whisk in the finely chopped tarragon and minced chives. Season with sea salt and white pepper to taste. Serve immediately over prepared seafood.
Chef's Notes
- The physical success of any beurre blanc depends heavily on the temperature differential between the warm reduction and the cold butter. Do not shortcut chilling the butter cubes.
- Using a heavy-bottomed saucepan is critical. Thin pans create localized hotspots that will instantly break your delicate emulsion in a fraction of a second.
- White pepper is specifically chosen over black pepper in classic French emulsion sauces to maintain a clean, unblemished visual appeal.
- If you must hold the sauce for a dinner party while finishing other components, pour it into a pre-warmed insulated thermos rather than attempting to hold it on the stove, which usually results in splitting.
Storage
Refrigerator: 1 day — Refrigeration will break the delicate butter emulsion. Quality degrades significantly upon cooling.
Reheating: Warm very gently in a bain-marie over low heat, whisking constantly with a splash of cream to stabilize. Do not microwave or boil.
