Jerry Thomas' Bartender's Guide

HINTS AND RULES FOR BARTENDERS

25. When the consuption of a keg of beer is sufficiently rapid, it is best drawn directly from the keg, the first glass drawn being rejected. The tap must be thoroughly cleansed before using ; and, as soon as the beer ceases to run freely, a vent is placed in the bung.

When, however, the keg has to stand in use for some time before it becomes empty, a considerable amount of gas will escape every time the vent is opened, and the beer will soon become " flat, stale and unprofitable "at least for the consumer. To obviate this, and to keep the beer tolerably fresh to the end, the vent is not used, but a tube is inserted in the vent-hole, leading to a receiver or cylinder containing air, compressed either by water-power or a hand force-pump. This exerts a continual pressure on the surface of the beer, and prevents the gas from rising. Too great an amount of air-pressure should be avoided, because the beer will be driven too forcibly through the tap, and
fill the glass with more froth and less beer than a thirsty drinker would care to pay for.

The air in the cylinder should be drawn from a pure source, by means of a tube, if necessary, leading to the open air. The air in a cellar or even a close apartment is rarely pure, and would have a decidedly unwholesome effect on the beer.

26. Bottled Beer should be kept in a cool place or in a refrigerator, not in contact with the ice. The bottles ought to stand upright, so that any sediment will settle to the bottom. It is, therefore, not advisable to pour the last dregs of the bottle into the glass.

27. Syrups are peculiarly attractive to ants, flies, and other insects ; they should, therefore, be kept in closely corked vessels ; and, when in bottles for use, be kept in a cool place, properly corked, a rubber cork being most convenient, and the bottles standing upright in water. In this manner the bottles will be put of the reach of insects of every kind.