Friday, 30 March 2012

T & J Bernard's New Edinburgh Brewery (part two)

This time we get to look at the actual brewing equipment at Bernard's Slateford Road brewery. Exciting or what?

We'll start with two of the more prosaic pieces of brewery kit: the grist hopper and hot liquor tanks. Not very glamorous, but certainly essential.

"Reluctantly leaving this beautiful prospect, we resumed our studies, and passed across a foot bridge to take a look at the grist hopper then being filled from the elevator. It is a large square iron receiver, tapering towards the bottom, capable of holding eighty quarters of malt, and is placed over the tuns below. To view these vessels we had to descend to a lower stage or gallery On our way we came to two hot-water tanks, each holding 120 barrels, protruding a few feet from the wall, the larger and hidden portion being carried over the roof of the next house, while another boiling tank is situated in the opposite corner of the building. They are both heated by steam coils from the exhaust pipe of the engine, and in front of them are two steam automatic traps for cutting off the condensed water."
"Noted Breweries of Great Britain and Ireland, vol. 3", Alfred Barnard, 1890, pages 118 - 119.

That's very green, isn't it? Using the exhaust of the steam engine to heat the water tanks. I can't help trying to fit the numbers together any time I read a passage of Barnard that includes any. To mash and underlet - the initial phase of the mashing process - about 3 barrels of water are needed per quarter. So 80 quarters would require 240 barrels. Or the exact capacity of the two hot water tanks. That's reassuring.

"The mash-tun stage, which is a splendid floor lighted by thirteen windows, contains three mash-tuns, two holding forty-six quarters each, and the other twenty-six quarters. They are copper vessels, encased with pine, and each contains the usual sparging apparatus and gun-metal draining plates. The grist hopper, before referred to, which is suspended over them, is connected with a large size Steel's mashing machine, which mashes three quarters of malt a minute, and serves the three vessels. The water used for mashing is obtained from the well, situated three-quarters of a mile from the brewery, by means of two 4.5-inch hydraulic lifting pumps, each having a stroke of 2 feet. These pumps are worked by a power pump at the brewery, which forces water at a pressure of 1,200 lbs. along two tubes, causing it to work like a solid piston-rod of great length, and acting on the plungers of the lifting pumps; these tubes, 1 7/8-inch, 5 w. g. and 1 3/8-inch internal diameter, have been tested at a pressure of 1,800 lbs. per square inch, and are galvanised inside. Between the well and the brewery is a 4-inch wrought-iron delivery pipe, also galvanised inside. The pumps are capable of delivering 1,200 barrels per day of twelve hours. The power pump is driven by the main engine, and requires about seven horse-power to work it."
"Noted Breweries of Great Britain and Ireland, vol. 3", Alfred Barnard, 1890, page 119.
The hopper and Steel's masher are clearly visible at the top left of the illustration. The vessels to the right are, I believe, two of the coppers.

You must be getting used to my brewhouse maths. I wouldn't like to disappoint you. Multiply the mash-tun capacity in quarters by four and you get the approximate capacity in terms of finished beer. That's two of 184 barrels and one of 104 barrels. For a total of 472 barrels per day. Assuming 300 brew days a year gives an annual capacity of just over 140,000 barrels. They weren't actually making anything like that amount. Between 1890 and 1895, the largest amount brewed in a single year was 67,000 barrels. It looks to me like they built the Slateford Road brewery with an eye to the future, with plenty of spare capacity. The optimism of late Victorian brewers is admirable. Just as well they didn't know what was around the corner.

You know as well as I do that it would be unusual if they didn't have a Steel's masher. But here's another excuse for some mathematics. At 3 quarters a minute, it could fill the larger tuns in just over 15 minutes. Much nicer than half an hour of manual stirring with paddles.

Now on to the coppers.

"From the mashing stage we looked over the balustrade and observed, on a lower gallery opposite, three handsome copper vessels, one of them closed with a domed cover, the other two open. They are used for boiling the wort with the hops; two of them boil eighty barrels, and the other 140 barrels at one time. The design of these coppers is a little different from those we have seen before, the curvature being dissimilar, and the crown somewhat higher. The furnaces which heat these vessels are on the paved floor of the brewhouse ; the fuel with which they are fired being raised in barrows by the steam hoist, by means of hinged blocks which lift up as they pass through the trap doors, so that the loaded barrows cannot fall."
"Noted Breweries of Great Britain and Ireland, vol. 3", Alfred Barnard, 1890, page 119.

Once again, there are both open and closed coppers. Why did they have both types? Were the open ones for Pale Ale, as we've seen in other breweries? I can only wildly speculate. Maybe you can help me about their design. It sounds to me as if each copper has its own furnace, placed underneath it. Are these direct-fired coppers? I think they probably are. The alternative would be to use a steam coil, which is how they were heating water in the hot liquor tanks. This is one of the first breweries I've come across in Scotland that does appear to use direct-fired coppers.

The smaller coppers seem a bit small relative to the mash tuns. A 46-quarter mash tun, assuming two roughly equally-sized worts, would require a copper of 90 to 100 barrel capacity. Another indication that they weren't brewing at full tilt. I don't believe that the coppers could handle the wort that all three mash tuns could supply, if running in parallel.

We'll finish with another of the more mundane pieces of equipment, the hop back.

"On a level with this stage there is a hop room for a few days' supply of hops, quite contiguous to the tops of the coppers. The hop-back, another copper vessel, holding 120 barrels, to which the wort now runs, is placed over the coolers in the next building, and contains gun-metal draining plates.

Under the mash-house floor we were shown a movable platform, on wheels of great height, which runs across the floor to enable the brewers men to get at the bottoms of the elevated vessels when required. The mash-tuns all discharge their draff by means of a wooden shoot, which is attached to an iron one leading into the draff-house, a small detached building in the yard."
"Noted Breweries of Great Britain and Ireland, vol. 3", Alfred Barnard, 1890, pages 119 - 120.

Very practical, that, having the hop store next to the top of the coppers. Now there's something I have personal experience of, throwing hops into the copper. That and filling kegs with AK are the only real functions I've ever performed in a brewery. I don't count mouse clicks. The system of removing spent grains (draff) was also neat. At least no poor bugger had to climb into the mashtun and shovel it all out.

Next it's the turn of cooling and fermenting.

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