Page:A Practical Treatise on Brewing (4th ed.).djvu/124

108 of the above fermentation, because it is the most insidious and dangerous, as also the most common and least known or understood. How often do we hear of mawkishness in the taste which cannot be accounted for. We may rest assured that in nine instances out of ten, it proceeds from the inert fermentation, and not from want of boiling, to which it is generally ascribed.

Before the remedy can be known, the cause must be traced; every experienced brewer will then know how to proceed.

This, to look at, is the most formidable of the irregular forms of the process, and proceeds also from unsoundness in the worts, or occasionally from bad yeast; for which also there is no certain remedy but tracing and removing the cause. It commences, like others, with a creamy top, but the curl rises very light and faint, and in patches over the tun. The light yeasty head has an ugly, bluish-white appearance in some parts of the tun, while in others it has a fretful blistery appearance, and only just covering the beer: this is accompanied with little or no attenuation. The stomach, although sometimes pungent, is neither healthy nor vinous. When the light yeasty head disappears, no other head rises, and the fermentation very soon assumes the appearance of a boiling cauldron.