Page:A Treatise on the Culture of the Vine and, and the Art of Making Wine.pdf/209

 mena, shall be considered under each respectively.

It sometimes happens in cold countries, but particularly when the temperature is below the 54° of Fahrenheit, that the must deposited in the vat does not undergo any fermentation, if means are not resorted to, to heat the mass, such as introducing a portion of itself heated, agitating strongly the liquor, heating the surrounding atmosphere, covering the vat with cloths, &c. But immediately on fermentation commencing, the heat advances to intensity, and sometimes a few hours suffice to carry it to the highest degree; in general, it is in proportion to the swelling of the mass, and increases and decreases with it.

The heat is not always uniform throughout, it is frequently more intense towards the centre, especially in cases where fermentation is not sufficiently violent to confound and mingle all its parts. The head is, in this case, broken afresh, and agitated from the circumference to the centre, to establish, as far as possible, an equal temperature.

The following facts may be established as incontestable:—

1st, That at an equal temperature, the greater the mass submitted to fermentation, the greater