Pour the minced shallots into the saucepan. Add a little coloured spirit vinegar then the white wine. Reduce the mixture until the liquid is completely evaporated being careful not to burn the sauce. Allow the reduction to cool. Add more liquid to the mixture such as white wine, aromatic stock, fish stock or simply water.
The liquid and the butter mixed together will form the emulsion. The butter can be cold or at room temperature. It does not make any difference. Bring the shallots and the liquid to the boil once more. Then start adding the butter a few pieces at a time over high heat, constantly whisking to emulsify the mixture.
Carry on the process until the desired quantity is obtained. After including all of the butter, whilst still whipping, bring the sauce to the boil which will stabilise the “beurre blanc”. Don’t forget to season the sauce.
It is also possible to flavour it with aromatic herbs or spices. Strain the sauce through a sieve if desired. To keep it warm, place it in a double boiler bowl. The “beurre blanc” can be held intact for two hours.