From The Brewers’ Guardian – 1883
The operation of artificially hardening a water, or “burtonising,” as it has been called, is so simple, that it is not surprising that many brewers who have heard of the wonderful beers produced at Burton, see their way to attaining equally successful results. The addition of soluble lime salts to a brewing water may be effected in various ways; by placing lump gypsum in the well or liquor tank, by adding powdered gypsum to the hot liquor prior to mashing, or by using one of the many water-hardening nostrums which our manufacturing chemists prepare.
It is not difficult to increase the hardness of a water by some 20 or 30 degrees, so as to make even a soft water somewhat resemble the famous brewing waters of Burton-on-Trent; but even when this has been accomplished, many brewers find their results far from satisfactory; they may also obtain a supply of yeast from Burton, and yet fail to produce beers with the Burton character.
We know of an instance where a brewing was made with some burtonised water, and malt and hops identically the same as used in a Burton brewery, some of the same yeast was used for pitching, and the brewing processes were carried out in exact imitation of the Burton system; the only difference in the two brewings was that at Burton a natural hard water was used. whilst in the other brewing an imitation Burton water was used; in the result, the two beers differed very materially. This can only be accounted for by supposing that in the artificial hardening of water, the lime salts do not exist in the same state of combination as in the natural water.
The experience of medical men tells us that artificial mineral waters do not have the same beneficial effects on the human economy as mineral waters derived direct from their natural sources, but no explanation of this difference is yet forthcoming. May we not say the same of brewing with artificially hard waters; it is quite possible there is some hidden virtue in a naturally hard water which we have not yet succeeded in imitating.
Crescent City Brew Talk 