Comment: Today a recipe calling for mustard is likely to specify style (country, dijon, plain yellow etc) but will be assumed to be a thick liquid substance. Cookbooks of the 19th century were the reverse: “mustard” came as either plain mustard seed or else in pre-ground form known as “flour of mustard.” Pre-mixed mustard of the modern sort–packaged in jars or pots–was starting to be available in stores but only in major cities and at much higher prices. As the all-purpose grocer still lay in the future one would seek out the condiment at an apothecary or drugstore.  Kitchener’s book reveals its English origins by use of the term “oil shop,” an expression most often seen in books by Charles Dickens or other British writers of the mid-century. They sold oil of types from sweet (olive oil, used for cooking) to sperm (from the whale of the same name, used for lamp lights.)

Flour of mustard (dry mustard, mustard powder)
vinegar, white wine or other liquid (see recipe)

Mix (by degrees, by rubbing together in a mortar) the best Durham flour of mustard, with vinegar, white wine, or cold water, in which scraped horseradish has been boiled; rub it well together for at least ten minutes, till it is perfectly smooth; it will keep in a stone jar closely stopped, for a forgnight [two weeks]: only put as much into the mustard-pot as will be used in a day or two.

The ready-made mustard prepared at the oil shops ismixed with about one-fourth part salt: this is done to preserve it, if it is to be kept long; otherwise, by all means, omit it, The best way of eating salt is in substance.

Obs. Mustard is the best of all the stimulants that are employed to give energy to the digestive organs. It was in high favour with our forefathers; in the Northumberland Houselhold Book for 1512, p. 18, is an order for an annual supply of 160 gallons of mustard.

Some opulent epicures mix it with sherry or Madeira wine, or distilled or flavoured vinegar, instead of horseradish water. The French flavour their mustard with Champaigne and other wines, or with vinegar flavorured with capers, anchovies, tarragon, elder, basil, burnet, garlic, eschalot, or celery; warming it with Cayenne, or the various spices; sweet, savoury, fine herbs, truffles, catchup &c, &c., and seem to consider mustard merely as a vehicle of flavours.

N. B. In Mons. Maille et Aclocque’s catalogue of Parisian “Bono Bons,” there is a list of twenty-eight differently flavoured mustards.

From: The Cook’s Oracle or Household Manual, by William Kitchiner M. D. 1832.