Page:A Practical Treatise on Brewing (4th ed.).djvu/128

112 climates. For stock beers, therefore, which have to stand the summer of this country, the same process will be found the more certain.

At what time the troublesome, tedious, and wasteful process of skimming the yeast off the gyle-tun was introduced, we do not exactly know. We have no doubt, however, that its introduction proceeded from unsoundness in the worts, and consequently fretful fermentations.

By frequently taking off the heads in a fretful fermentation, we no doubt ultimately produce a better appearance. This having been discovered, probably led to the general adoption of that system in certain parts of the country.

A better appearance of the head produced in this way will not, however, tend much to the production of better beer, unless the original cause of the prior ugly appearances have been removed. Indeed, we have seen beer which had been nearly a fortnight in the gyle-tun, undergoing the process of skimming, and having apparently a fine, close, yeasty head, but at the same time smelling and tasting sour. In other instances, we have seen beer left in the gyle-tun to flatten, as it is called; instead of which, however, the beer was gaining heat from a second fermentation, which had distinctly taken place without the brewer being aware of it. The further