This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
Starch, such as that contained in the grain of cereals, Barley to wit, if subjected to moist heat begins to undergo fermentation, and is presently converted into sugar - maltose - at which stage further fermentation may be arrested by dry heat, the whole process being that of malting. Then if an extract is obtained from the malted grain, and some of it in a syrupy form is given together with foods which are starchy, this will materially aid their digestion, in a weakly person, by stimulaing their saccharine fermentation in the stomach. For instance, a specially digestible pudding may be made thus: Stir an ounce of ground malt into a pint of hot, but not boiling milk; strain through a sieve, and add the milk to two ounces of well-soaked rice. Mix well, and stand for ten minutes in a warm place; then bake for an hour. But it is to be noted that the diastase, or active principle of malt, is killed by a temperature higher than 147° Fahrenheit. For preparing a Malt extract which the patient of feeble digestive powers may take with farinaceous starchy foods, three piled tablespoonfuls of crushed Malt are to be soaked in half a pint of cold water over night, and strained through muslin until clear, on the next morning.
This liquid may be preserved in a tightfy-corked bottle, with the addition of a teaspoonful of good brandy; though it is better to make it fresh every day. Add one tablespoonful thereof to a basin of milk, or gruel, for malting the same.
From the manufacturing chemist convenient Malt-extracts can be now procured, which are prepared by evaporating down an infusion of malted barley at low temperatures, or in vacuo, so as to preserve in an active form the diastatic ferment present in the Malt; these extracts being given with the view of enriching the supply of carbohydrates in the diet, and helping to malt the starchy foods which are taken additionally. Dr. Hutchison says, however, that for persons with whom the digestion of starchy foods is difficult, a Malt extract is not the best preparation to employ. It will be a far more certain plan, and cheaper, as well as pleasanter, to make an infusion of Malt at home, and to either use it as a beverage at meals, or preferably to stir some of it into the starchy foods, such as puddings, gruel, etc., before they are eaten.
Dr. Ringer directs that the Malt extracts, if given for the reasons we have stated, should be sipped during the progress of a meal whereat any starchy food is eaten. "Do not," says he, "as is frequently advised, give the Maltine, or Malt-extract at the end of a meal, when admixture of the food mass with the acid gastric juice secreted by the stomach during first digestion is now well advanced." Though Professor Foster tells, as a physiological fact that the acidity of the stomach's contents promptly after a meal is at first quite feeble; indeed, with man, in some cases at least, for some time after the beginning of a meal no free acid is present in the stomach, and during this period the conversion of starch into sugar may continue therein uninterruptedly, with neutral surroundings.
The making of malted bread consists in adding to its substance some Malt extract, obtained by evaporating an infusion of malted barley to a syrupy consistence at a low temperature. This contains the ferment, diastase, which is able to convert starch into soluble substances (maltose, and dextrin). When therefore Malt extract is mixed in the dough with its part of the starch, this latter is ultimately converted into Malt sugar, and dextrin. In other words, part of the starch is digested. But it is important to remember that this ferment diastase, is readily killed if exposed to a high temperature: hence its activity inevitably ceases whenever the bread enters the oven. If then any considerable part of the starch of the dough is to be converted, the Malt-extract must be added very early in the process. (Dr. R. Hutchison).
Malt extract is of two-fold value, - as a drug, and as a food. It converts the starches into sugar, thereby affording warmth and fat; so that in health the relative effect of a meal of bread and cheese, taken with or without some wholesome beer of malt and hops, was well recognized by our working folk long before any special preparation of Malt extracts became introduced. Thus it is that good London porter, and nourishing stout, are well understood to possess a nutrient value independent of their moderate percentage of alcohol, particularly for thin and weak invalids.
A Malt extract of established repute as the parent of all those now supplied for helping the invalid, (and declared by the Lancet to supersede them) was introduced by Hoff, of Hamburg, in 1862, and still holds a supreme place in medical esteem. It is a soluble carbohydrate, being thus an ideal fat-former; and whilst almost entirely free from alcohol, it will serve as an excellent substitute for alcoholic drinks, since the next step to saccharine fermentation in starchy foods is that of the vinous change, (a measure of which most probably occurs as digestion goes on to its completion.) Thus it happens, moreover, that the Hoff's Malt extract helps to soothe nervous disquietude, or wakefulness at night. A small wineglassful is given, either warm, or cold, together with a principal meal, either once or twice daily. This extract is not fermented after the manner of Malt liquors in general, which always provoke further acid fermentation with gouty persons, and give trouble to their kidneys. Dr. Hutchison instructs his readers, that as to augmenting the supply of carbohydrates, or converted starch-products, by giving Malt extract, the fact is that treacle and golden syrup contain a considerably higher percentage of sugar, and are much cheaper, though Malt sugar is less apt to disagree, since it cannot be directly taken up into the system.
On mixing about one part of Malt, ground into flour, with from four to eight parts of oatmeal, an excellent and easily digested material for porridge is obtained, which is strongly to be commended for persons of feeble digestion. Mattieu Williams teaches that by adding the ferment principle (diastase) of vegetables to materials which are starchy, we transform the tissues thereof into dextrin and sugar; on which principle he once converted an old pocket handkerchief, and part of an old shirt, into sugar, (but not profitably as a commercial transaction). Such sugar is glucose, like that of honey and of grapes. It is less sweet than cane sugar, or that of beet, but a better food. When Sydney Smith was at Foston, in Yorkshire, where he built the "Rector's Head" Tavern, he gave fermented grains to his pigs, which afterwards "went fuddled about their sty, grunting God Save the King".
Under stress of circumstances other vegetable matters than barley can be used for brewing an acceptable kind of beer as a wholesome beverage. In the first recorded American poem, written during 1630, when civilization there was as yet primitive, and "the place where we lived was a wilderness wood," it was told: -