Danish brewing in 1960 - lagering and packaging

It's a sad day. My little series on Danish brewing is drawing to a close. We'll be looking at the final phases of the brewing process.

Starting with one of my favourite processes, lagering. I've seen a fair bit of discussion on homebrewing fora about how long you need to lager and even whether there's any point in bulk lagering at all. I won't claim to understand the science, but from my experience drinking beer, a proper long lagering definitely helps. All the Franconian beers I love get at least two months.

"Lagering.—The green beer was racked to the lager cellar by pumping. The yeast had usually compacted firmly on the floor of the fermenting vessel and it was not appreciably disturbed during racking, so that a retaining collar was rarely necessary. Much mixing of gyles took place in order to obtain a consistent product and also, where the method was in use, to mix yeast types. At this point in the process precipitating agents such as tannic acid were sometimes added.

Cellars were maintained at about 32° F. and the beer was allowed to reach this temperature naturally, standing in tanks which were bunged about a day after filling, either column-wise or singly. Many cellars were vast underground refrigerated passages, but new installations above ground enclosed the tanks in cold rooms, leaving the ends accessible from a working passage at room temperature. Enamelled iron, aluminium and stainless steel were used for lager tank construction, with aluminium now predominant. Pressures were allowed to rise to about 4 lb. per sq. in., which is lower than in Germany where subsequent carbonation is not allowed, and the average storage time was up to 3 months for Pilsner types and 6 months for very strong beers."
Journal of the Institute of Brewing, Volume 66, 1960, pages 497 - 498.

Blending gyles is typical of big industrial breweries who want to maintain absolute consistency of flavour. For me part of the charm of some beers is that there are slight variations from batch to batch. Makes life more interesting.

The lagering process sounds pretty traditional: gradual cooling to about freezing point and bunging the lagering vessels to allow the beer to carbonate. Though obviously they didn't solely rely on natural carbonation as the Germans did. Funnily enough I know from documents in the Barclay Perkins archives that Harp Lager was bunged and naturally-carbonated in the early 1960's

Now filtration, a vital part of Lager production.

"Filtration and bottling.— In 14 of the 16 breweries visited in Denmark and Germany, the final polishing filtration was given by a pure cotton cellulose pulp filter of the Enzinger type. Pulp polishing was considered essential for stability of the finished beer, in spite of the disadvantage of regenerating and sterilizing the pulp and the possible loss of beer quality. Four of the Danish breweries used a battery of centrifuges for rough filtration, with additional cooling equipment between the centrifuges and the pulp filter; they were not so efficient as kieselguhr rough filters and they thrust more load on to the polisher. For example, a 50-plate pulp filter used after a centrifugal pre-filter passed about 300 brl. before choking whereas 400 brl. were passed after prefiltration by kieselguhr. The sludge from the lager tanks was usually filtered through a cloth filterpress, and the beer recovered was led through the main filtration plant and metered into fresh bright beer."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I've included that for information purposes only I can't claim to understand hardly any of it. My knowledge of filtration methods is close to zero. Not anything I ever bothered with when home brewing. Very efficient of them to recover the beer in the yeast sludge. Better than the disgusting practice of some British breweries of reusing returned beer.

Now they're fizzing the beer up.

"Carbonation took place just before the pulp filtration, and bright-beer tanks were usually glass lined. Two large breweries had a rigorous check on dissolved air before bottling, and any excess over 2 ml. per litre was scrubbed out by bubbling carbon dioxide through the tank. The extent of carbonation was standardized and chill-proofing agents were sometimes added. Bottling lines were always well laid out, with hot water spray pasteurization in bottle commonly applied; the usual practice of a 20-min. hold at 143° F. for a 0.33-litre bottle seemed rather drastic."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I can't really say much about this either. Other than that large breweries were clearly concerned about oxidation and that pasteurisation seems to have been standard. Though that was also true of British bottled beer at the time, with just a handful of exceptions.

Finally, draught and canned beer.

"Keg beer constituted a proportion of the home trade of some breweries, and here pasteurization by complete immersion was favoured for thorough heat transfer and so that leaking kegs could be detected. Export beer in bulk was flash pasteurized. Canning was rather the province of the major concerns, but it was obviously on the increase and at least one firm was preparing to raise its output of canned beer extensively. Standards of stability for beer in bottle were high. Vibration and forcing tests were regularly carried out with, e.g., one type of beer being expected to withstand a temperature of 140° F. for 3 months without throwing an appreciable haze."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I can remember being shocked during my first visit to Copenhagen back in the 1980's at the almost total absence of draught beer. Even in largish city-centre pubs, draught beer was rare, except in British or Irish pubs. It was the only real beer-drinking country where bottles so completely dominated the pub trade. That's one of the many aspects of the Danish brewing scene which have completely changed. Now draught beer is everywhere.

It sounds as if not all breweries really bothered with draught in 1960, but some did. But presumably between 1960 and 1980 even those gave up on it.

Next we'll be looking at German brewing in 1960.