Sunday, 25 June 2017

Fermentation at Carlsberg in the 1880's (part two)

We're going to take a look at how Carlsberg kept their fermenting worts cool back in 1881.

They had a slightly unusual method of cooling:

"In the Carlsberg breweries they do not use ice floats for keeping down the fermentation heat in the tuns, but instead, they direct a flow of cold air right into the upper surface of the tun, this method although it did not possess any other advantage than cleanliness, and saving of labour, is to be recommended, by this means the heat of the tuns and also of the tun room is under perfect control. The cold air is prepared as follows. The ordinary atmosphere is drawn through a quantity of cotton into a room which is surrounded by cold brine or glycerine, after passing the room the fan which drew it this length, again forces it into a wooden conduit running between the tuns. This conduit is fastened close to the roof, the current onto the fermenting wort can be caused be opening a lovre board in the side of the conduit. This louvre can be open from a mere slit to its full width. The temperature of the cellar is constantly 43º F and the fermenting wort at all times practically the same. The tuns are not roused to mix up the yeast as this seems to be done by the wort running from below."
"Notes of a visit to the breweries of Messrs. Jacobsen Senr. & Junr. Copenhagen Sept 1881." held at the Scottish Brewing Archive, document number WY/6/1/1/11.
No advantages other cleanliness, saving manpower and precise temperature control. They all sound like pretty important points. It sounds like a primitive sort of air conditioning. It also reminds of the small breweries I've visited in Bavaria. They all have an enclosed, refrigerated room to house their fermenting vessels.  Presumably that's the easiest method of cooling when you have open fermenters.

I assume that the cotton was to filter any crap out of the air. Well, the big bits, at least. Don't think that would be fine enough to keep out airborne yeast.

I've not heard of an ice float before. Accoring to "Industrial chemistry, a manual based upon Payen's 'Précis de chimie industrielle'" by Benjamin Horatio Paul, 1878, page 953, it's:

"a painted sheet-iron tray filled with ice, which is placed in the wort."
You'd need to make sure that the paint was intact, otherwise you'd be getting rust in your wort in addition to cooling it.

At the Valby brewery they had what appears a more primitive arrangement:

"In the new tun room at Valby the arrangements are practically the same except the cooling of the tun rooms. Here the tuns are arranged in two rooms placed at right angles to each other. Alongside both inner walls is placed the ice house the floor of which is about level with the bottom of the tuns. This arrangement of ice and tuns is carried up three stories the middle flat being about 3 to 5 feet below the level of the ground. The upper flat is only used for fermentation during the winter when artificial cold is unnecessary. The middle and lower flats are in use all the year round, therre is no communication between the flats excepting by an outside corridor & stair. Neither pipe nor air holes are in the floor. The racking and filling pipes are built into the outer side wall, the cold is obtained direct from the ice, through hinged shutters closing against air passages 12 inches by nine, which for the middle floor are admitted to the ice house on a level of the roof of the second flat. The under flat is similarly fitted but the air passages into the ice house are fewer, smaller and situated close to the level of the roof of the tun room."
"Notes of a visit to the breweries of Messrs. Jacobsen Senr. & Junr. Copenhagen Sept 1881." held at the Scottish Brewing Archive, document number WY/6/1/1/11.
It seems this system of cooling didn't work particularly well. And also was likely to infect your wort:

"Although this house has only been in operation part of this season Mr Jacobsen Jr. has found that the middle fermenting room does not work as satisfactorily as he anticipated. The lower room works very well. To cool his wort he has to make specially iced water besides what he obtains from the melting of the ice and as this ice can only conveniently be taken from the bottom it makes an ugly inroad on his stock. This is being remedied by having a supplemental ice house for the sole purpose of cooling the wort to the pitching heat. When we compare the atmosphere in Carlsberg with the Valby tun rooms, the latter is certainly not to be preferred. It wants the crisp, enervating character, the clearness, and sensible general purity the former possesses. Besides coming from the one to the other one is struck with a peculiar indescribable difference, and which is at once felt to be a want. As to the ice house s they are constructed of brick with inner spaces in the walls, the real floor being of wood. A full description of these will be found in Mr. Kerr's report. Suffice it for me to say that already the ice is melted for from three to four feet back from the wall leaving the ice standing in one mass with perpendicular walls which have a blackish and rusty, slimy feel, and appearance. The walls are already coated with a layer of slimy fungus, the floor is nearly as bad, especially where the ice has melted away completely, giving a dangerous footing for workmen and positively no guide nor grip on the wall for the hand, this latter is an important matter as the floor has a considerable slope and walking on it at the best insecure. Dr. Hansen says that wort exposed in the Valby tun room gets contaminated at once with foreign and diseased ferments, while in Old Carlsberg tun room this does not occur."
"Notes of a visit to the breweries of Messrs. Jacobsen Senr. & Junr. Copenhagen Sept 1881." held at the Scottish Brewing Archive, document number WY/6/1/1/11.

Slimy ice - how wonderful. I'm not surprised worts became infected. The ice house was also a danger for the poor buggers who had to work in it. Sounds like an all-round disaster.

Finally something random about tun-room lighting:

"Regarding the lighting of the tun rooms, Carlsberg are lit with open windows placed three feet apart and closely fitted and cemented. They are placed at intervals of 12 feet along the wall, the air space between the windows is never renewed. In Valby the two upper flats are lit in the same manner i.e. double open windows but the distance between the two seems to be rather less. The lower tun room in Valby is lit with gas, and I may remark that this is the first lager tun room or lager cellar that I have seen lit by this illuminant."
"Notes of a visit to the breweries of Messrs. Jacobsen Senr. & Junr. Copenhagen Sept 1881." held at the Scottish Brewing Archive, document number WY/6/1/1/11. 

Lager cellars next.


Anonymous said...

Some microbiologists use cotton in their test tubes to separate environments. Although foam probably used a lot more now.

Lars Marius Garshol said...

I guess that method of cooling explains how Carlsberg ended up with wild yeast from the orchard outside the brewery in their backslopped yeast two years later.

Jeff Renner said...

Wahl and Henius mention ice floats on page 680 of American Handibook of the Brewing, Malting and Auxiliary Trades, 2nd edition, 1902, "Swimmers consist of a half globe shaped vessel, about 3 feet in diameter, used for cooling the wort. They are filled with ice and floated upon the surface of the wort."