We’ve seen the chart of 1903 cellaring practice by the British Army, that is, for beer sold to soldiers in canteens. That the Army was a discriminating customer is evident by the care it took when selecting brewers to tender (see my earlier discussion).
As discussed and elaborated on in comments to the last post, it is clear that this “code” stipulated no venting of porter casks before dispense, unlike for bitter and in a more restricted way, for mild. An exception was where the porter or stout were “forcing”, meaning in active fermentation to the point some carbonation needed to be vented. This was probably noticed by gas emitting from fissures in the barrel or perhaps by sounds given off.
It seems clear that no venting was done because the beer was wanted in lively condition to form the famous head of porter and stout. Many references to a foaming, thick head for porter and stout can be found in English and Irish brewing historical literature. Here is just one, from the text The Brewer.
Guinness achieved this, before the nitrogen-dispense era, by using a “high cask” system. Active fermentation was induced by adding partially-fermented beer to fully-fermented stout before being sent out to the trade. The German equivalent was krausening. Some brewers used wort – completely unfermented beer – for this purpose. This caused a roiling fermentation, and the high cask wouldn’t have been vented over days in the cellar, as the high condition was wanted.
High cask beer was mixed in the glass with older, flat beer (in Ireland) from an adjacent “low cask”. In Britain, there can be no doubt that some brewers did something similar. There are references in English manuals to it, although it seems the practice was less widespread than in Ireland.* But English brewers had other ways to induce high condition. Adding priming sugar was one way increasingly favoured toward the end of the 1800s.
However the condition was put in, enough pressure had to exist to force the beer out without using a porous spile in the shive. For mild the 1903 manual stated simply to remove the bung (no shive) and lay it lightly over the hole. Unlike for bitter they didn’t wait seven days to dispense mild, it was dispensed in two days. This makes sense as any longer would bleed out most of the carbonation with that size aperture in the barrel. Mild was much less hopped than bitter, possibly a factor too in the quick dispense.
Oxidation had to affect, in some degree, bitter ale treated this way. Is it fanciful to think this echoed for the drinker the oxidized notes of India Pale Ale aged and shipped to India over a multi-year period?
This brewing article (1909) of the period ascribed head-making qualities in porter and stout to “caramel”, meaning surely caramel malts. I doubt these alone would produce the “rich head” mentioned. Carbonation had to do most of the job.
I’ve been to a half-dozen CAMRA festivals in England since the 1980s, at which some porter was served. Never very much, but some usually was, and mild. I’ve had cask porter, stout, and mild in many pubs there over the decades. The same for North America, at festivals where cask ale was served and of course in pubs.
All this porter and mild was cellared the same as for bitter or pale ale, as far as I know. The reason, I think, relates to the fact that little porter and mild are sold today. Refinements for beer styles formerly ascendant have no meaning now, and surely over time the old learning disappeared in modern practice.
But at one time, naturally-conditioned porter and stout came foaming high in the glass with little of the cellarmanship associated with cask-conditioning today. The part of the 1903 guide that most resonates today is for bitter – and bitter, or pale ale, are by far the main sorts of beer that are still cask-conditioned.
The nitrogen-induced head of modern draft Guinness, albeit not from natural conditioning, resembles what the Army required circa 1900 much more than the cask porter of today which usually has almost no head. The same applies for any porter or stout served on “nitro”, and the canned versions. (Standard carbonated draft porter too but that is the modern equivalent of bottled porter and stout, which always existed – the soft carbonation of cask beer is better analogized to nitro and widget dispense).
Cask porter today can be an excellent drink, but I am making a different point.
N.B. From the Craft Beer & Brewing site, this 2017 article gives the lowdown on best cellaring practices today.
See our Part II for a continuation.