Tuesday, 8 March 2016

Guinness’s Park Royal Brewery in 1949 – the brew house (part seven)

The wort is finally getting the chance to turn itself into beer as we enter the fermenting tuns at Park Royal. Dead exciting, I’m sure you’ll agree.

Somewhat surprisingly for the date, Guinness had wooden fermenters:

“The tuns are of the totally-enclosed type and are constructed in Kauri pine, selected for its very well-known properties of hardness and smooth grain and low coefficient of heat conduction, the large ones being of 1,260 barrel capacity and are 28 ft. long x 26 ft. wide x 20 ft. deep. The small tuns are of 630 barrel capacity; they are 28 ft. long x 13 ft. wide x 20 ft. deep, the liquor dip in each case being 14 ft. 6 in. The ceiling of these vessels is formed by the reinforced concrete floor above, the underside of which is panelled in white glazed tiles.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 284.

The Kauri pine is native to Queensland in Australia and Papua New Guinea. From the description given of the wood’s characteristics, you can see why it might be chosen for making fermenters. A smooth grain means less opportunity for anything nasty to hide in it. And its insulating would have come in handy in a brewery, too.

Looking at those dimensions, the fermenters were quite deep at 20 feet. Deeper than they were wide, in the case of the smaller capacity ones. While the large ones weren’t far off from being cubes. Oh, and pretty large. Even large breweries like Bass had surprisingly small fermenters in the late 19th century. Rarely more than 100 barrels in size. Ones as large as 1,200 barrels I’ve never come across elsewhere.

As I mentioned earlier, Guinness were very unusual in having fermenters with a capacity equal to, or larger than, that of their mash tuns. Usually one brew went into several fermenters rather than the other way around as is common in modern breweries. At least the small to medium size ones.

“No provision is made for the collection of CO2 gas, but the gas flows over and through ports below the door sill to a gas trunking system connecting the fans which discharge the gas to atmosphere over the fermenting house roof. For removal of gas after tunnage, portable reinforced rubber pipes of 6 in. diameter and long enough to reach the bottom of the tun are connected up to the gas trunking system with quick bayonet fastenings. A tun can be freed of gas within half an hour to enable men to enter for washing down. No detergents are used in washing.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 284.

Unlike in German breweries where CO2 collection was required for force carbonation, British breweries often didn’t bother. Their open fermenters weren’t very suited to collection and, when much beer was in cask form, little CO2 was needed. Guinness still bottle-conditioned at this point so didn’t even require CO2 for bottling.

It seems the wooden fermenters weren’t without their problems:

“It may be mentioned that difficulty has been experienced in recent years in these days of low gravities and their attendant troubles, in keeping the surface of the timber bacteriologically clean, and to overcome this it has been decided to line them with sheet metal. The first choice was stainless steel, but owing to the prolonged delivery dates and last, but not least, the very heavy cost involved, aluminium has been adopted. The lining will be of 6 gauge thick aluminium sheet 99-5 per cent, purity to B.S.S. A3 of welded construction with felt and bitumen backing, and the necessary inlet and outlet connections will all be "cleaned up" to remove, as far as possible, all corners where infection could possibly find a lodging.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 284.

Keeping out bugs is, of course, the biggest problem with using wooden vessels in a brewery. Reduced gravities caused British brewers all sorts of trouble in the 20th century. It makes you realise how the old high gravities had allowed brewers to be less careful and still get away with it. When most beers were under 1040º a whole new set of skills were required.

And here are typical problems of the immediate post-war period: shortage of materials. And expensive materials. Brewers often didn’t have the luxury of using exactly what they would have liked. It must have been a frustrating time.

Not quite done with the fermenting kit yet. Rousers and skimmers next.


Anonymous said...

If you have information on their yeast I think it would be interesting for some future post -- what they might have done on cleaning it, testing it, that kind of thing. I think it would be illuminating to see how quickly the brewing industry picked up the advances of microbiology and when they started growing cultures and using microscopes to evaluate their yeast stocks, and when they moved from an informal testing process to a more rigid scientific approach.

Ron Pattinson said...


stuff about yeast collection is coming up.

Andrew said...

When I worked at Black Sheep one of the mash tuns was made out of wood and I wondered after working there if it was kauri pine. I think they had it checked once but Im not sure what the result was.