The best Water, to speak in general, is River Water, such as is soft, and has partook of the Air and Sun; for this easily insinuates itself into the Malt, and extracts its Virtue; whereas the hard Waters astringe and bind the Parts of the Malt, so that its Virtue is not freely communicated to the Liquor. It is a Rule with a Friend of mine, that all Water which will mix with Soap is fit for Brewing, and he will by no means allow of any other; and I have more than once experienc'd, that where the same Quantity of Malt has been used to a Barrel of River Water, and the same to a Barrel of Spring Water, the River Water Brewing has excell'd the other in Strength above five degrees in twelve Months, as I prov'd by a small Glass-Tube with a Seal, and was much preferable to the Taste, I must observe too, that the Malt was not only in Quantity the same for one Barrel as for another, but was the same in Quality, having been all measur'd from the same Heap; so also the Hops were the same both in Quality and Quantity, and the Time of boiling, and both work'd in the same manner, and tunn'd and kept in the same Cellar. Here it was plain that there was no difference but the Water, and yet one Barrel was worth two of the other. There is one thing which has long puzzled the best Brewers, which I shall here endeavour to explain; and that is, where several Gentlemen in the same Town have employ'd the same Brewer, have had the same Malt, the same Hops, and the same Water too, and brew'd all in the same Month, and broach'd their Drink at the same time; and yet one has had Beer which has been extremely fine, strong, and well tasted, while the others have hardly had any worth drinking. I conjecture there may be three Reasons for this difference: One may be the different Weather which might happen at the different Brewings in this Month, which might make an Alteration in the Working of the Liquors: Or, secondly, that the Yeast or Barm might be of different sorts, or in different states, wherewith these Liquors were Work'd: And, thirdly, that the Cellars were not equally good: for I am very sensible, the goodness of such Drink, as is brew'd for keeping, depends upon the goodness of the Cellars where it is kept; for at a Gentleman's of my Acquaintance, who for many Years has used the same Brewer, and the same Method, his Beer is always of the same Taste, his Cellars, or Vaults, are very dry, and have two or three Doors to them.