This section is from the book "Cookery Reformed: Or The Lady's Assistant", by P. Davey and B. Law.
Take two quarts of water and four spoonfuls of oatmel, with a piece of lemon-peel and a blade or two of mace; boil them for a quarter of an hour, and stir them often, taking care the liquor does not boil over; then strain it through a coarse sieve. At the time of use add some wine, sugar, and a little grated nutmeg.
Take two quarts of water and fix spoonfuls of oatmel; boil it as above, and drain it. Then add a quart of ale that is not bitter; boil it, and sweet-en it to your palate. Afterwards add half a pint of white wine. Or you may make it with half water and half ale, and leave out the white-wine.