It's basically a shortcut version of proper bottle-conditioning which misses out the lengthy - and costly - secondary fermentation in cask before bottling. You could argue that this is the way most modern bottle-conditioned beer is produced.
"Bottling Process No. II — Forced Bottling.
The large increase in the "tied-house" trade has no doubt been the cause of so many brewers taking up the bottling business, and together with an apparently growing dislike to the flavour of old matured ale, has led to the introduction of this method of bottling. In this process, comparatively new ale containing an appreciable quantity of fermentable matter is artificially clarified by the addition of finings, quickly bottled off, and the bottles stored in a forcing store at a temperature of from 65° F. to 70° F.
Secondary fermentation rapidly sets in, and the bottles are put in the trade for immediate use.
If consumed within a moderate time, say a week or ten days, the beer will pour out practically bright and in good condition, but it will have none of the best characteristics of true bottled ale, and if kept too long "fret" usually results and the beer becomes thick, depositing an excessive amount of yeast."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 195.
You may be asking yourselves why an increase in the tied house system would encourage more brewers to bottle. Simple: brewers had a financial interest in supplying their tied houses with as many products as possible, especially beer. They wouldn't want third-party bottlers to get the bottled beer trade in their pubs. A corollary of this was how Guinness and Bass kept their bottled products in the tied houses of other breweries. They let the brewer do the bottling and so get some of the profit.
This in fact sounds like the risky way of bottle-conditioning at home: guessing when there is enough fermentable material left to condition the beer but not enough to turn the bottles into grenades. I always plumped for the safer method: wait until primary fermentation has stopped and prime the bottles with sugar to give the yeast something to condition the bottles. Though if there's Brettanomyces in the beer even this method isn't completely safe, as it will consume sugars the Saccharomyces hadn't been able to digest.
Conditioning in a warm room after bottling is still carried out by some brewers, for example Moortgat with Duvel. That gets a couple of weeks warm conditioning before shipping.
It's clear that the author wasn't overly impressed with the beer produced this method of bottling.
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, pages 195 - 196.
What does he mean by "the true bottled ale flavour"? Is it the aged flavour produced by a Brettanomyces secondary conditioning?
I'm not sure that I agree with what he says next:
"Summer brewing being comparatively a modern custom, more especially in Burton, is more variable than winter brewing, and it is the bottling of summer-brewed ales that has given much trouble to the bottler, and led to a considerable modification of the usual brewing process and the production of ales of better quality.
Of late years brewers have, in some cases, so altered their process that pale ales can be bottled within a week or so of racking, and these ales, having an extremely small amount of fermentable matter left in them, and that not of a readily fermentable kind, do not enter into a too violent fermentation in bottle, so that when properly matured in the bottles they give great satisfaction. I have found beers of this kind mature very rapidly, and even within six weeks from rack develop a very high quality, but on the other hand these beers were undoubtedly more prone to deteriorate when kept for long time."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 196.
The evidence I've seen in the form of brewing records suggest that, in London at least, summer brewing was standard right at the beginning of the 19th century. Though I know that beers meant for keeping tended to be brewed in the cooler months. I've not seen many brewing records from Burton, but Truman were brewing in June, July and August 1877 at their brewery in the town.
The quote ends with what sounds like a description of a type of bottled running Pale Ale. It's a shame Lott doesn't tell us how the brewing process had been changed to remove most of the fermentable material by racking time. That would obviously do away with the need for a long secondary conditioning. Had they changed mashing techniques to produce a more fermentable wort? Or perhaps they had increased the proportion of sugar in the grist. Maybe a combination of the two. There would have been a big incentive to come up with such a process. By cutting 6 months or a year off the process of producing a bottled Pale ale, brewers would save a considerable amount of money. Remember that they had already paid the tax on the beer before it started secondary conditioning.
Next time we'll be looking at the slightly creepily-named artificial gas bottling method.