VINEGAR AND LEMON WHEY (Invalid Cookery)

A sickroom drink rather than a dish, and the original gives no quantities at all. The hinge is the straining: what you want is the clear liquid, not the curds.

• Working proportionsThe original is genuinely unquantified, and asks only for enough acid to throw "a small quantity of whey." A pint of milk with about two tablespoons of lemon juice or white wine vinegar will curdle it; how much clear liquid you draw off will vary, so adjust from there rather than trying to read a fixed ratio into the text.
• Strain itOnce the milk has separated, pour it through muslin or a fine sieve. The finished drink should be pale, thin and clear-ish. Any curd left in it turns the whole thing gritty and unpleasant to sip.
• Do not boil after the acid goes inAdd the acid to milk already at a boil, then take it off the heat. Prolonged boiling after curdling toughens the curd and clouds the whey.
• Vinegar or lemonLemon gives a cleaner result and is the better choice for anyone actually drinking it. If using vinegar, a plain white wine or cider vinegar only; malt and balsamic are wrong here.
• "An agreeable acid"Whey straight from the pan is sharp. Dilute with hot water until it reads as a mild lemon drink, then sweeten with a lump or two of sugar as directed.
• Yield and servingHow much you end up with depends on how far you dilute it. Serve hot, in a cup, and make it fresh each time; strained whey does not keep well.
• "Less heating"This is period medical language, not a cooking note. The comparison is presumably with wine whey, a similar sickroom drink made with wine in place of the vinegar or lemon.