thickening, they are added in equal proportions to the sauce JUST BEFORE SERVING: re-heating would spoil the flavour of the sauce.
Kneaded Butter Liaison.—This form of liaison is exceedingly useful when no roux is at hand, and a little additional thickeing is required. Butter will absorb about its own weight in flour, and the two are kneaded together on a plate until all the flour is absorbed, or, in other words, thoroughly moistened by the butter. This liaison should be added to the sauce in small portions and stirred until it is smoothly mixed with it.
Blood Liaison.—This liaison is used principally to thicken sauces for game and poultry entrées. The blood of poultry or game should be mixed with a little vinegar, to prevent coagulation. It should be strained and added gradually to the sauce a few minutes before serving.
Arrowroot, Cornflour, Fecule Liaison.—Before adding any of these substances to the sauce, they must be smoothly mixed with a little cold stock, milk, or water. The liaison is stirred into the boiling sauce, and simmered for not less than 2 minutes to cook the starch.