Starch is an important constituent part of food, as it assists, with sugar and gum, in forming the fat of the body, and in carrying on the respiratory process; but, separately; it is used for stiffening and glazing muslins, etc. etc., which are thus preserved clean longer, as well as made to look better. Clear starching was introduced in the reign of James I., and the first clear starchers were Dutch women. The yellow starch, introduced and made fashionable by the infamous Mrs. Turner, who was hung for assisting in the murder of Sir Thomas Overbury in the Tower, went out of fashion at her death, as she was hung in a yellow starched ruff.
Many vegetable substances afford starch; the chief are wheat, rice and potatoes. Arrowroot also makes a delicate but expensive starch. "Wheat starch is made by soaking the grain in cold water till the husk separates and the farina is softened - i.e., till the grains are full of milky matter. The mass of grains thus softened is then put under pressure, which forces out the milky fluid. This is let stand for some days. A slight fermentation takes place; the gluten is decomposed and changed into acetic acid and alcohol, while the starch remains undissolved. It is taken out and washed in cold water, then slightly coloured with blue and heated in an oven until it cracks into the pieces in which we buy it.
Rice starch is procured much in the same way, but as it contains almost no gluten it is made more easily.
Potato starch is made by grating raw potatoes into a vessel full of clear water, and after sluicing it well, letting the mass settle. The water is poured off and fresh water added three times; then the starch remains at the bottom of the vessel.
Arrowroot starch is made by simply pouring a little boiling water on the powder.
Starch will not dissolve in cold water; it requires boiling water. Its price is from 5d. to 8d. per lb. It should be kept in a jar, in a dry place.
Stone-blue is merely indigo reduced by adding whiting or starch. It is used, tied in a bag, to blue water into which .washed linen or muslin is dipped. Powder-blue is smalt mixed with a very little starch.