A pressure gauge seems a pretty obvious thing to fit to your tank. Wouldn’t want the thing exploding.
“A good pressure gauge with a range from 0 to 50 lb. is necessary, and a safety valve, which should be fixed at the highest point. The safety valve should be adjusted to come into action at the maximum pressure to which beer is required to rise. In any case, the safety valve must blow off at the maximum figure allowed by the authorities. A glass gauge should run the full depth of the vessel and show die number of barrels contained. It may be found necessary, in the case of beer which is particularly stubborn in developing condition, to introduce CO2. A tap should therefore be inserted for this purpose with a screwed end on the outside fitted with a carbonator internally. A further tap for sampling the contents of the vessel will also be found useful.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 333.
Fascinating that a CO2 inlet was considered an optional extra. Which implies that the beer in the tank was conditioning itself. Which would explain the need to keep rousing it. A degree of fermentation was required to generate CO2. Presumably any filtering occurred after the conditioning phase.
This next passage confirms that: the beer went to the tank straight from the fermenter. Or cleansing vessel. Odd to see that mentioned as specific cleansing vessels were out of fashion. A couple of breweries still had Burton unions and in the South dropping fermentation was still reasonably common. But far from every brewery had a cleansing vessel. While in the 19th century they were universal, in one form or another.
“The usual procedure adopted with the system of conditioning in bulk is to run or pump the beer direct from the cleansing or fermenting vessel into a tank. In this way the time necessary for maturing may be only ten days or a fortnight, although longer periods can be given. In this time condition and the required pressure must be developed. With light gravity beers and stout the procedure may be adequate, but for best pale ales there is room for improvement, on our opinion. In the case of old and strong ales previous storage in vats or casks is advantageous. In fact, we believe that if it were possible to substitute oak vats for metal ones considerable improvement would result in the ultimate character of the beer. Unfortunately, we are afraid that oak vats cannot be made sufficiently air-tight to retain the internal pressures. But we see no reason why wooden vats should not be used as intermediate maturing vessels, between the cleansing or the fermenting vessels and conditioning tank. Such a process might involve additional pumping with ordinary beers, but in the case of old ales it would be preferable to lengthy storage in numerous casks.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 334.
I’m surprised that beer was left as long as two weeks to condition. I’d been expecting no more than a day or two. But I suppose they were letting it carbonate naturally. Do you know what it reminds me of? The method of Lagering Skol. That was left to carbonate naturally in a tank, too, though the temperature was lower.
I’m truly gobsmacked at the suggestion of using oak vats for conditioning. It seems like a backwards move. Though it’s rubbish to say that oak vats can’t be made airtight. How on earth could Germans and Czech lager in oak vessels? You just need to line them with something – like pitch – that is airtight.
The bit about Old Ales confirms my suspicion about London-brewed Burton Ales. I suspected they were usually aged in trade casks. Mostly based on an image in Barnard’s “Noted Breweries of Great Britain and Ireland”, showing a cellar full of casks marked “KK”. I can see several disadvantages in maturing in trade casks. You wouldn’t get an consistent degree of maturation across the casks, especially if there were ones of different sizes. Consistent ageing was one of the reasons huge vats were employed for Porter.
Next time we’ll be actually filling our tank. Won’t that be exciting?