Brewing Ingredients And The Process
Cask beer is made from four essential raw materials – malted barley, water (or liquor as we brewers call it), hops and yeast.
Barley is a cereal crop which is grown extensively around the world and provides a variety of feed uses. However, brewers will use only the best varieties because at the heart of every good beer lies barley. The grain used imparts both colour and sweetness to the beer. Barley undergoes a process called malting after it has been harvested before it can be used in the brewery. In the malting process the grain is first ‘steeped’ in water after which it is encouraged to germinate. Germination makes starches more readily available as food for the growing plant and also develops enzymes within the grain which the brewer can use later to break the starch down into sugars. The germination process is halted by kilning – that is heating of the grain to dry it out, a process which also imparts colour. The maltster exhibits great skill in stopping the germination at the right point, and drying the grain safely for storage without damaging the precious enzymes. By altering the malting conditions, a number of different types of malt can be produced, which may be used in cask beers, for example pale ale malt, crystal malt, chocolate malt, black malt.
The source of the liquor used for brewing is very important and all brewers seek a consistent, potable supply, with many having their own boreholes. Indeed the ready availability of a good quality brewing liquor supply was historically a key factor in choosing the site of a brewery. These days there is the possibility to treat water by, for example, softening it or by addition of salts, such as gypsum (a process often referred to as ’Burtonisation’) to create a desired profile for the type of beer being brewed.
Hops provide bitterness and aroma in beer, and also act as a preservative enhancing shelf life. They are said to have been brought to England by Flemish weavers in the 15th Century, initially being used for the preservative characteristic. At that time their use distinguished between beer which was hopped, and ale which was an unhopped beverage. This distinction has long since passed into history and with improved microbiological control in the modern brewery the preservative aspect is less critical. Hops are generally classified as to whether they are used for bittering the beer, for providing aroma, or both. Traditionally UK breweries would have used hops predominantly grown in Kent or Hereford & Worcestershire, but varieties from around the world are now used to give a myriad of different flavours to beer.
Yeast is added towards the end of the cask ale brewing process to start the process of fermentation. Every brewer will have a preferred strain of yeast for each of their brews. Each strain can exhibit differing fermentation performance and capability, and each can also give rise to different by-products of fermentation, which results in alternative flavours in the beer produced.
General Notes on The Process As Carried Out By Black Country Ales
The brewing plant at the brewery behind the Old Bulls Head in Gornal is sized at 15 brewers barrels (each barrel being 288 pints) meaning that 15 barrels of beer is produced per batch which will ultimately end up in around sixty casks of 9 gallon size for delivery to the pubs. A recent expansion would allow the production of up to 8 brews per week with appropriate shift working.
Our First Brews
First brew was 5th November 2004, it was a brew of BFG.
First brew in the new Brewhouse was Gyle 627 (Pig on the Wall) on 2nd April 2012.
First brew into one of the new FVs was Gyle 1738 (BFG) on 2nd December 2018.
We use malt which has been pre-milled for us by the maltster and has been delivered to us in 25kg sacks. Milling breaks open the husk of the barley grain and exposes the starchy inside so that we can get the goodness out in our Brewhouse. The amount of malt used in a brew is called ‘the malt grist’ and ours is mostly Pale Ale Malt (about 300kg per brew) with a small amount of Crystal Malt in some of the darker ales and milds. We also add a bag of Torrefied Wheat to each brew, which assists in giving final beers with a good head retention on serving in the bar.
In the mashing process, the milled malt is mixed with hot liquor at around 72oC (we call this the striking temperature) to create a porridge-like consistency in the mashtun. The malt cools down the liquor and we aim to achieve a temperature in the mash of around 65oC. We then allow the mash to stand for upwards of an hour, during which time the enzymes produced during the malting process break down the starchy foodstore of the barley into soluble sugars, creating a strong sugary solution which we call wort.
The wort is then run out of the bottom of the mashtun into the copper or kettle, as it may also be known. The husk material remaining from the barley acts as a filter bed so that we end up with nice bright worts. To ensure we get maximum extract out of the malt, we spray hot liquor at 77°C over the top of the grist in the mashtun, a process called sparging. This washes out any residual sugars from the grain bed and once complete, we can then bag up the spent grains which are taken away and used for horse feed.
Once all the wort has been collected from the mashtun, it is brought to the boil and boiled for up to an hour and a half. At this stage in the process we add the third ingredient, hops. A portion of the hop grist which we term early hops is added to the copper at the start of the boil, and some are added as late hops at the end of the boil. Early hops contribute the majority of the bitterness to the beer, whilst late hops will enhance the hoppy aromas developed in the resulting beer. As well as extracting the bitterness from the hops, boiling serves to sterilise the wort, to concentrate it, and to bring about denaturation of proteins in the wort. These proteins come out of solution and form what is called a hot ‘break’ in the copper. It is necessary to separate out the wort from this hot break and also from the hop residues. At Black Country Ales we achieve this by discharging the copper via an upstand, leaving behind the hop/protein residue called trub. The clear worts are run through a counter-current heat exchanger which cools the wort down to 20°C, whilst heating cold liquor up to generate hot liquor ready for the next mash.
As the wort is cooled, further protein comes out of solution, which we call cold break. The cooled wort is collected in a fermenting vessel, and once we are satisfied that we have collected the right volume at the right strength, then we add our final ingredient, the yeast. The yeast in effect feeds upon the sugary wort solution and passes out alcohol and carbon dioxide (CO2) as a product of the fermentation process, turning our wort into ‘green’ beer over a course of 3-4 days. The fermentation process also gives out a lot of heat and the temperature of the green beer will initially rise in the fermenter, but then cool down again as the speed of fermentation declines. Once we have nearly reached the desired end point of the fermentation as measured by the present gravity of the beer, we then cool the fermenter which slows the process even more, and after another day or so the beer is ready for transfer to the next stage.
Green beer can contain a lot of undesirable aromas/flavours, which disappear as the beer matures. The green beer is run off from the fermenter into racking tanks sited on a trailer, leaving behind the majority of the yeast which has now done its work and has settled to the bottom of the fermenter. The next process at Black Country Ales then is to take the trailer of beer to our warehouse and to then rack the beer into a mixture of kilderkins (18 gallon casks), firkins (9 gallon casks) and pins (4.5 gallon casks). At the time of racking we add isinglass finings which cause residual yeasts to collect as sediment in the bottom of the cask, but not before they have fermented a little more of the residual sugar. This generates more CO2 and washes out undesirable aromas from the beer. Part of this process termed conditioning takes place in the public house cellar as the cask is carefully put into position for serving (an action termed stillaging) for 24-48 hours before it is put on sale.