Here's the introduction, which discusses the different methods of producing bottled beer"
"To enable the non-technical reader to follow more exactly the ensuing extract from the "Bottling" Sipplement, it may be well to give a brief description of how modern non-deposit beer is produced.That must be chill haze that he refers to in naturally-conditioned bottled beer. Not a problem I ever have myself as I keep all my bottles in the living room. They never get cold.
In the old days when beer was "naturally matured" in bottle the process consisyed simply of filling bottles with draught beer, sealing them, and then storing them in a moderate to warm temperature for some days or weeks. Under these conditions fermentation took places within the bottle, and the resulting gas, being unable to excape, was absorbed in the beer, to be released when the cork was removed. The objection to this method was that there was always a sedimentary residue left by the fermentation in the bottom of the bottle, which was prone to stir up and cloud the beer on decanting. This type of bottled beer also inclined to cloudiness in cold frosty weather.
The first efforts to surmount these objections consisted of filtering draught beer, to remove all traces of yeast, and then forcing CO2 gas into it, as is done in the case of mineral water. This method was unsatisfactory for many reasons, the most obvious being that if beer is treated like mineral water it tastes like it.
The modern method referred to in the article in "Bottling" consistes of the linking of these two methods. Firstly, the beer for bottling is transferred into the hermetically sealed glass-lined maturing tanks, where it matures just as if it were in a bottle. It forms its own gas by fermentation, making artificial gas unnecessary, and of course it "throws" a heavy sediment.
The next stage consists of chilling the matured beer and storing it in the cold room at 32º F. The object of this process is threefold. In the first place, it removes the possibility of the beer going cloudy if it gets cold again; in the second it ensures the "fixing" of the gas in the beer so that it does not burst out as soon as the bottle is opened; and, finally, it renders it "quiet" enough to bottle, for obviously it is a serious problem to fill bottles with highly conditioned frothing beer.
Actually the filling process is carried out under pressure in the counter-pressure filling machines; but before this the beer has all been filtered through sterilised cotton pulp to render it star-brilliant, and afterwards, if the beeer is of the dark variety, it is pasteurised to render it fit for long storage. Bitter beers, however, are not usually subjected to this process, as it is apt to damage their more delicate flavour.
"A Modern West Country Brewery" by H.C. Vickery, 1934, pages 1 - 2
I'm not so sure about the filtered beer tasting like mineral water. Sounds a bit far-fetched to me. Though letting the beer mature in tanks before filtering definitely sounds like it would improve the beer. A bit like secondary conditioning in a cask, which was the old method. In this description, they make it sound as if with the naturally-conditioning method the beer was racked straight into bottles. In reality it was matured in the casks for a period of weeks or months.
Chilling before bottling was the classic way of avoiding chill haze. After this treatment you could be sure that it was safe to chill the beer down to that temperature - in this case just below freezing - without risk of a haze.
Interesting about not pasteurising Bitter. What dark beers could they be talking of? Presumably Brown Ale and Stout.