The advert is quite wordy, which is good for me, as it includes a few nuggets.
"Bass & Co.’s European Brown Stout,
BREWED ESPECIALLY AND SOLELY FOR BOTTLING.
The Water of Burton-on-Trent is celebrated for the peculiar excellence of its brewing properties, and the Stout now manufactured there by Messrs. BASS & CO., from the very choicest qualities of English Hops and Malt, bids fair to rival in worldwide popularity their East India Pale Ale.
The supposition that Burton Water will not, or that Burton Water cannot make good Stout, is gratuitous and erroneous, and founded only on the fact that the demand for Burton Ale has hitherto been beyond the possibility of supply, causing the brewing of Stout for the time to be a matter of secondary consideration.
Messrs. BASS & CO.’S Stout is not introduced as a cheap Stout, but one which, being brewed especially for bottling and family use, has a distinct character of its own, is absolutely free from any trace of acidity, and is as pure, grateful, and nourishing, as the best materials and skill in the science of brewing can produce.
It is bottled with the most scrupulous care in Imperial Pint Bottles, which are all labelled with Messrs. BASS & CO 's Brown Diamond Trade Mark, and secured by Patent Metallic Capsules, bearing the COOPER CO.’S ”CASTLE” trade mark, so as to guarantee its being genuine.
It can be obtained at 4s. dd. per dozen Imperial Pints, from all Wine Merchants and Grocers, and at Clubs and Hotels;
and Wholesale from
THE COOPER COMPANY,
HOP EXCHANGE VAULTS, SOUTHWARK-STREET, BOROUGH, LONDON, S.E ,
AGENTS FOR MESSRS. BASS AND CO.,
Who will also deliver it in quantities of not less than four dozens to private customers in any part of Town, or at any Railway Station in London, if a difficulty arises in obtaining it in any particular locality.
PRICE. Imperial Pints. Bass’s European Extra Brown Stout 4s. 6d. per dozen. Bottles (if not exchanged) 2s. " Bin Cases (if sent by rail) 4s. 6d. per 2-doz. Case.
Islington Gazette - Friday 31 December 1875, page 1.
I'm not sure that Burton water is particularly suited to brewing Stout. An opinion shared by some brewing scientists.
"To begin with, then, it is not customary to employ saline waters, or, in other words, if such water be employed the black beer produced is deficient in that roundness and fulness of palate taste that is considered so necessary a feature, while I can example this by referring to the black beer produced at Burton, which has been universally described as a mere black pale ale — i.e., though black in colour, its palate taste reminds one very strongly of the pale beers produced by Burton firms. It will be quite understood that I am not decrying this article; it may and does suit many palate tastes, and is thought a great deal of on the Continent, but at the same time it differs very widely from the accepted standard quality of a black beer as specified."
"The theory and practice of modern brewing" by Frank Faulkner, 1888, pages 259-260.
And there people were thinking that Black IPA was recent invention. Maybe its popularity on the Continent is why Bass called it European Brown Stout.
That's a good excuse - the demand for Burtion Ale was so high that Bass had no time to brew Stout.
Bottled beer wasn't really a big thing in 1876 - it only really started to catch on a decade or two later when new bottling techniques were adopted. Which makes it interesting that this was a bottled only product. Being totally free of acidity implies that there was no Brettanomyces secondary fermentation. That is, it was bottled without any ageing. Which would have been very unusual for a Stout.
After digging around in old price lists, I'm pretty sure that I know which Bass beer they're talking about: P2 or Extra Stout. Which would give it an OG of around 1075º. That was their second strongest Stout after P2 Imperial Stout. It definitely wasn't a cheap beer. 4s 6d for a dozen imperial pints is the same price as Bass Pale Ale, which was an expensive beer. Though it had a lower OG of 1065º.