Flowers Brewery Ltd. Brewing School visits 1968 to 1969
Flower & Sons Ltd, Stratford on Avon
Visit by Brewing School students - 20 January 1969
A subsidiary of Whitbread & Co. Ltd which is about to cease production with only two brews of Mackeson & Co Ltd remaining. Equipment has been listed and distributed around the Group. Much older equipment will be discarded. Much has already gone. Conditioning tanks and the keg plant have been completed. Beers will be absorbed in the group and production mainly switched to the Luton plant.
Built in 1950 on the general tower principle, at the top malt handling is in the centre with hot liquor tanks at either side to help keep the malt dry. There are two Boby mills identical in external appearance although 50 years difference in manufacturing date. The 1902 machine has a smoother casting! Adjunct is distributed throughout the run. There are three vertical brewing systems consisting of grist case, mash tun, copper and hop back. The grist cases are fitted with spreaders. Mash tun capacities are 70 quarters, 20 quarters and 50 quarters. Circulation pipes are fitted to the hot liquor tanks to allow agitation in case calcium sulphate treatment has not dissolved. There are also traps before the sparge arms to catch any suspended gypsum. Hot liquor tanks are controlled to one to two degrees which is flexible in the case of colder weather.
Mashing heat is 151oF. Grains are removed by slurry pump and rakes help mix the spent grains with incoming liquor. There are valentine runoff controls. Coppers are 360, 130 and 260 barrels respectively and are boiled under 1-2psi pressure. A vapour recovery plant heats cooling water to 180oF, the condensate is discarded. The brewery once used Paul's Green Malt Extract which was the same price as malt but cut out the kilning stage which paid for the concentrating process. This was used to increase mash tun output in the summer by 25% to save extra brews. It is said to have given extra fullness to the flavour of the beer.
Some of the hops are slurried in water and ultrasound treated to produce dry hop and copper material. The liquid is collected in the racking room and the residual solids go to the copper for blending with untreated hops. We noted the beer in the sample room had a rather harsh after taste reminiscent of other breweries adding extract at racking. Note there are pneumercators to detect the volume in the copper.
Hop backs cannot by be used by any other copper than the one above it which must lead to some inflexibility in the case of breakdown. The smallest hop back has five to six barrels of sparge. Spent hops are removed by a vortex pump. There are two wort receivers and four double paraflows using chilled and well water. The water side is cleaned in place each week with 2% nitric acid which is kept ready in a tank.
There is an assortment of FVs, 125 barrel copper rounds dating from 1870 to 600 barrel stainless vessels. Until five years ago there were Burton Unions. Some vessels are stainless steel clad and the welding has given has given trouble. Fly catchers operating the fermenting room attracted to blue light surrounded by live wires. Movable attemperators which are situated near the top of the wort level.
27 barrel priming dissolving vessel for liquid cane, lactose and caramel for the Mackeson & Co Ltd. Conventional skimming system used. Pressurised in yeast tank to press. Collect bottoms in separate long tanks. Yeast sold to English Grain Company. There was only Mackeson yeast in the yeast store and that had autolysed considerably, it is supposed to be used less than seven days after pressing.
All Mackeson & Co Ltd goes out in bulk
A self discharging 160 barrel per hour centrifuge was used for keg beer before conditioning in 20x160 barrel tanks . The mains are glass. There was hot filling of cakes 160°F for four and a half minutes. Cheaper than sterilising kegs and pasteurising. 100 barrels per hour with two men, that is 400 kegs per hour. Radioactive detector for level in keg which blows a hooter if incorrect, no provision for removing offending keg from the line automatically.