The amber wort being let down, at its proper degree of heat, into the fermenting tun, out of the whole quantity of yeast allowed for this drink, in the table, page 317, one seventh part must be kept to be used as hereafter shall be mentioned. Suppose the heat of the air is at 40 degrees, and eight quarters of malt have been brewed for this purpose; the whole of the yeast required is seven gallons, from which one is to be reserved.[39] Of the six remaining gallons, one half, or three, are to be put to the wort oh its first coming down, when the whole must be well roused, or mixed, thoroughly to disperse the enlivening principle the yeast conveys, hereby to prevent putrefaction, or foxing in any part, and of the last three gallons, about three quarts must be added to the drink, every twelve hours, until it ferments to the highest pitch of the period mentioned in article 5, page 319. This successive putting in of yeast is called[40]_feeding the drink_; before and about the time the head is got to this height, all the dirt or foul yeast, that rises on the surface, must be carefully skimmed off; it is easily distinguished from the pure white froth, by its color, and by the sinking of the head occasioned by its weight. Length of time might attenuate some of these coarser oils, in a less artificial fermentation, but as this help is not to be waited for, and every obstacle to pellucidity must be removed, the brewer’s attention to this point cannot be too great.--The head of the drink having reached its utmost height, the reserved gallon of yeast is to be used, in order to give to the ale a sufficient power to bear the repeated fermentations it is to undergo, by being beat in, every two hours, with a jett or scoope, for one quarter of an hour, so that the head on the drink is each time to be reduced to the least height it is capable of. This striking in being continued, the drink will periodically require it, and be damaged if it be neglected. After it has undergone more or less of these fermentations, in proportion to the heats of the worts and of the air, the brewer is carefully to observe, when the head ceases to rise to its accustomed height, and then to examine the drink, by having the jett filled with it at the bottom, and brought through the whole body to the top, a small part of which being poured in a handgatherer, he will see whether the lees form themselves in large white flakes, and readily subside, and be informed, by the taste, whether the sweet of the wort is gone off, and the ale become vinous. If these two circumstances concur, the drink is to be beat in with the jett as before, but not roused as porter or other beers are; for the lees, which in this drink are in greater quantity, would, by this management, so intimately be mixed with it, as with difficulty to separate themselves again, if at all. It is then time to cleanse it; but the casks, at all times, more especially in summer, must be well