"The processes of brewing are most interesting. Pumped from the wonderful wells of the town into great tanks, the water passes into boilers, and, after reaching boiling point, is drawn into huge mash tubs, where it is mixed with malt. Here the "Porcupine," with its long teeth, constantly revolves, and converts it into a pulp of a certain evenness. Time is then allowed for the chemical changes which convert the starch into saccharine, and the clear liquid, or "wort," is run into a capacious wooden vessel, which opens into the "coppers." In these coppers the hops are added, and after a long period of boiling the liquid passes through the "Hop-back," which contains the hop-refuse, and is then converted into ale by the process of fermentation, in the fermenting squares. In this "Square" room the Excise officials make their calculations on which the excise is charged to the Company, and the turgid yellow liquor pours into troughs, each six feet deep, and holding 2,000 gallons. The yeast having been added to the liquid in the "squares," converting the saccharine into alcohol and carbonic acid gas, the "wort" at last becomes ale, which passes through the "Union Room," to be thoroughly cleansed from its yeast, thence into the racking squares, from which it is racked into casks ready for delivery. The construction of the barrels themselves in the steam cooperages is a revelation to the outsider, the staves of Russian oak are cut and pressed into shape by hydraulic machines with such accuracy that, when finished, they are completely water-tight; every detail, down to vent-pegs and bungs, being completed by special apparatus."
The Graphic, March 21st 1908, pages 410 - 411.
That stuff about the porcupine converting the malt into a pulp is a bit misleading. Not sure the author really understood what was going on in the mashing process. The porcupine is presumably an internal rake mashing machine. At least he does accurately describe the beer's time in the unions as cleansing rather than fermentation.
The text does confirm something: the use of small fermenters in Burton. 2,000 gallons is approximately 56 barrels. Very small for a brewery making nearly 30,000 barrels a week. I make it 519 fermenters of that size that you'd need for a week's production. It seems an awful lot. Why didn't they use larger ones?
Russian or Memel oak had long been British brewers' favourite for making casks. Mostly because it was the oak that imparted the least flavour. Unlike their modern counterparts, brewers didn't want any oak character in their finished beer. They went to considerable effort "seasoning" barrels to prevent them flavouring the beer inside them. Remember this is a period when Bass Pale Ale for bottling was likely to spend at least 6 months maturing in a hogshead.