Page:A Practical Treatise on Brewing (4th ed.).djvu/227

Rh rootlets; By the boiling-heat the diastase loses the power of converting starch into gum and sugar: this therefore, is the substance by the action of which saccharification takes place in the mash-tun.

This completely accounts for an almost instantaneous change of colour in the extract, which invariably takes place in the mash-tun during the first mash, when the heats are properly taken.

If, therefore, this change of colour do not take place, we may rest assured that our mashing temperature is wrong.

It also proves what has been already stated in the foregoing pages, that nearly the whole of the extract is made in the first mash, and that all we do afterwards is merely washing out that which remains of the extract in the grains.

It also shows the importance of taking our first mashing temperature properly. By the boiling temperature, say the French chemists, the diastase loses the power of converting starch into gum or sugar. Thus setting the goods in the tun.

It may be possible that a considerably lower temperature than the boiling may have the same effect of destroying the power of the diastase; indeed we know that it does so, as goods have often been set at much lower temperatures than boiling. As already stated, therefore, under the head of Mashing, we should rather turn on the first liquor too