Davenports (C&B) Ltd. Brewing School visits 1968 to 1969
Davenport's Brewery Ltd, Bath Row, Birmingham 15
Visit by Brewing School students – October 1968
The company dates from the late 19th century when brothers Davenport set up business in Birmingham, one looked after the brewing and eventually owned some 200 back street pubs, the other dealt with cask racking and bottling hence the company's name Davenport (C&B) Ltd. Eventually in the 1920s, in order to expand the door to door service of the Company which had started with hand barrows some 40 years earlier, the backstreet pubs were sold and the brewery concentrated on ‘Beer at Home’. It still retains some 81 houses over the country but it is dependent on the ‘Beer at Home’ aspect as illustrated by their worst trading weeks being the last two in July!
The buildings date from 1880 to 1926, the plant used and the methods employed are a mixture of ancient and modern. They boast of having one of the first stainless steel Alfa Laval paraflows installed in 1947 and also pioneered in yeast propagation plant. Failure to develop in other departments e.g still fining from jugs could mean a tight fisted managerial outlook or the lack of return on modern installations since the firm considers little further expansion is possible. However, the brewery appeared clean and light, chessboard floor tiles and ceramic wall tiles abound, the latter often with the company’s malt and hops motif. I have no personnel figures but in the brewhouse and fermenting room few operators were in evidence.
Mill room
Malt is in half quarter sacks from commercial maltsters and is carried to an intermediate floor by lift where enough for one week's brewing (5 days) is stored. The lack of space and the similar price for bulk malt explains their continued use of sack. 120 sacks go into each brew and each mash has a small proportion of crystal. A 15 quarter per hour bucket elevator fitted with dust extraction carries the malt to the mill room upstairs.
Mill room
The malt is screened to remove chaff and small grains as well as larger material. Magnets remove any metallic objects although they have suffered a number of explosions due to flints associated with the chalky subsoil which produces good malting barley. The malt is weighed and crushed through three four roller Seck mills at two tons per hour. The machines once belt driven from a common engine are now in the process of conversion to individual power. The malt passes between the first set of rollers, is shaken and the remaining integral grains pass through the second set. Flaked maize is added to bitters up to 8% and flaked barley to milds by an adjuncts hopper. The grist is collected in grist cases to await mashing.
Liquor
There are three hot liquor tanks; two stainless and one cast iron. The liquor comes from a well 300 feet below the brewery. It is treated with calcium chloride and magnesium sulphate at the rate of 3 ounces per barrel. Further chloride for stouts and sulphate for bitters is added to the grist case.
Mashing
Three mash tuns will mash 60 quarters per day divided equally between a 28 quarter stainless tun and 2x25 quarter cast iron tuns. The mashing which starts at 6am is carried out at 149°F for bitters, 153°F for mild and 160°F for stouts (their stouts are very sweet). The striking temperature in the hot liquor tanks is some 4°F higher. There is no automatic control but there were recording charts so the process is run manually in response to the instruments. A stainless steel tun with a flat hinged top is fitted with a Steels machine. A valentine gauge controls the runoff through eight pipes with a small differential so that the mash is never drawn down onto the plates. The mash is seven feet deep so care is needed. The use of flour in the grist was deemed unsuitable for their system. The motorised sparge causes some difficulty at low speeds because the larger holes near the centre of the arm tend to deliver large drops which pit the surface. The other tuns have arms which work from the water pressure so always produce the required spray. The grains are removed manually. Mash tun 1 with a cast iron base to its stainless steel upper has sheared its attaching bolts and ripped the lagging due to the different expansion rates of the metals.
Coppers
There are three coppers; one at 180 barrels and two at 90 barrels. Bulk cane sugar is added up to 10% with caramel to colour. Davenports run six coppers per day; hopping at the rate of one pound per barrel of the best quality Kent and Worcesters. 10% of the hops are held back until 20 minutes before casting to provide hop aroma in the product. Also at this time Irish Moss is added at the rate of 1 ounce per quarter of malt to assist coagulation of the break. The boil time is 2 hours normally although sometimes there is an 8-9% boil off to a required gravity. Yeast food may be added at the copper stage.
Hop backs
The brew size here is some 500 barrels; all passes through a single hop back of 160 barrels capacity. There is re circulation to obtain brightness. The hop bed of about 400 pounds per day is removed by hand. The wort is pumped to a 180 barrel Adlams wort receiver where it is kept for 10 minutes to keep the transfer in balance. Hot wort is aerated and passes through an Alfa Laval paraflow at the rate of 90 barrels per hour where it is cooled from 190oF to 60oF. The recovered hot water is used for cask washing or returned to the hot liquor tanks.
Collection
The cold wort is collected in 12 CVs of 80 barrels capacity. Each day to eight to ten are filled. The brewery operates a partigyling system, so the wort is divided and broken down with different volumes of liquor as necessary. The system gives three or four types of beer from a single mash. The wort is held here for 12 hours for Excise dipping and then run down to fermenting vessels leaving a good deal of precipitate behind.
Davenports have their own yeast obtained from a Copenhagen culture plant when required. The culture sequence takes 10 days and go as follows, 2 litres charge to one barrel then to 10 barrels. The yeast consists of three strains, one readily floculates, one stays on the bottom while the other ferments well. Monday's brew is skimmed on Thursday for Friday racking etc. The strain usually last eight to nine months in use. The pitching rate is one pound per 1045 barrel; delivered by glass mains mixed with chilled wort from the refrigerated room. Attenuation is then as follows 1041 to 1009 in the vessel, 1033 to 1007 and 1065 to 1019.
The brewery unit is 65 barrels and the 24 fermenters have capacities of 65, 130 or 195 barrels. There is only one dirty head which is not very dirty mainly due to the use of CVs. There is little beer stone. Three skims are taken by gravity with no rejection. All the yeast is pressed on the rotary vacuum drum and the pressings returned. The yeast for keeping goes to a cold store while the other four parts go to Marmite. There is no wet yeast storage. The yeast remains in eight-pound trays for a maximum of 8 days after which time only 5% are dead. Small trays allow adequate circulation. Before pitching (at eight trays per 65 barrel unit) all yeast is tested for bacteria floculation and viability. Lime washing assists in vessel cleaning which is done manually and sterilised by formalin.
Hops are stored supposedly under slightly chilled conditions although two gaping holes in the wall might make this difficult. A selection of Kent Worcester and Yugoslavian hops are kept with some cans of extract.
Racking
the racking back of five-barrel capacity acts only as a reservoir. The beer in metal or wooden casks is fined in cask before dispatch. Cask washing at 90 units per hour is done on a mechanical drive Hopkins machine with one cold, two hot and one steam stations. And old machine is kept in reserve.
For kegging, pasteurisation takes place through a heat exchanger where beer is held at 160°F for 20 seconds; it is cooled and fed to two kegging machines. The machine steams the kegs to 195°F, a counter pressure of CO2 removes condensate.
Bottling stores
The bottling side of the concern is a separate company. They bottle about four times as much bottle to draught as other breweries. 17 depots provide basis for the door to door service. They bottle at the rate of 15,000 barrels per week where the brewery output is more like 4,000. A refrigerated brine plant provides brine for two chillers to cool the incoming beer to 32°F. Two carbonators provide gas to 2.5 volts CO2. Chilled carbonated beers are centrifuged and filtered to give a bright product. 90 conditioning tanks are in use with a capacity of 65 barrels each. Lager remains in vessel for three months, others for 14 days, seven warm and then via a filter to remove the dry hops to seven days cold. A pressure of 15 psi CO2 is maintained. Guinness is conditioned in tanks for some 14 days also. Flash pasteurisation takes place in line to the bottling machines.
Four bottling lines are in use each capable of 800 units per hour. The bottles are put in standard half dozen crates stacked on pallets by hand ready for transportation There is also an 800 can per hour plant which can only operate when the bottling line stops. The cans filled are of four and seven pint capacity the success of this venture can be gauged by the sales of 45 shilling can openers last Christmas (20,000 were sold).