Every week our maltster delivers a variety of different malts to the brewery. At present this comes in 25kg sacks with one delivery weighing up to as much as six tonnes. This equates to a lot of beer... approximately 70,000 pints! The sacks are unloaded off the wagon by hand, stacked onto pallets and then fork-lifted up to our malt storage/milling area ready for commencement of the brewing process.
1. Milling the Grain
The weekly malt delivery, unloading and storage
The malted grain is then put through our two roller mill to reduce the grain particle size suitable for rapid enzymic digestion. The milled grain is then auger-fed up into the Grist Case ready for the next stage.. ‘Mashing’. The Grist Case is essentially a large hopper into which several different kinds of malt are mixed together during milling depending upon the type of beer being made.
At Copper Dragon we only use the best possible malts for our beer. Maris Otter (a premium brewers malt guaranteeing superb colour and flavour) is our core ingredient and accounts for 99% of our malt usage leaving 1% for other specialists malts (chocolate, black, wheat and roasted barley).
The milled/blended grain is then transferred from the Grist Case into the combination Mash/Lauter Tun where the next stage, Mashing takes place.
Top quality Maris Otter malt being milled and transferred into the Grist case (right)
2. Mashing
Salts being added to the mash by the brewer facilitating ideal ionic conditions
Mashing is the process of mixing the milled grain with hot water (Liquor) encouraging enzymes in the malt to convert the starch in the grain into sugars, typically maltose. During this stage, liquor treatment salts are added at the mash to facilitate ideal ionic conditions. The mash is then maintained at approximately 65-degrees C over a 90 minute period.
Mashing conditions are adjusted by the brewer to produce the required specifications for each individual brew and at the point of ’Conversion’ (where all the starch has been converted into sugar) the mash has now turned into a sugar solution called ‘Wort’ where it is then ‘Lautered’ in the next stage.
3. Lautering
Glass underbacks enabling the brewer to check clarification (above) and inside the Mash/Lauter Tun
Lautering is a 2-stage process involving the separation of the Wort sugar solution away from the spent grains.
Stage 1
The Wort is passed through plates in the bottom of the Mash/Lauter Tun separating it from the spent grains. As the filtration process occurs, the spent grain forms a bed which in itself becomes a filter helping in the clarification process of the solution.
Progress of this is monitored by brewer who can check the clarity of the wort as it passes through glass underbacks. These draw the beer from a variety of different positions at the bottom of the Mash/Lauter Tun helping the brewer ensure that complete clarity is achieved throughout the brew.
Stage 2
Once the wort is completely clear of any impurities, hot water is ‘Sparged’ (sprayed) onto the top of the grain bed via a rotating circular spray arm. This removes any remnants of sugar and colour from the grain and once complete, the Wort is transferred into the Wort Kettle for boling..
4. Boiling the Wort
Boling of the Wort in the Kettle (above) and the heat exchanger (right)
The Wort is then boiled in the Kettle for approximately 90-minutes. During the boil, any additional sugar is added along with English & Continental hops (these contribute bitterness and aroma compounds to the beer). They gradually isomerise producing the desired bitterness whilst proteins in the wort coagulate.
The boiling process has the added benefit of sterilising the beer and has to very carefully controlled to ensure an even boil. To achieve this, high temperature steam is passed through steam-jackets around the outside of the Kettle bringing the Wort up to boling temperature.
Once the boil has been completed, time is allowed for settlement of the Trub (hop residue) into a central collection cone at the bottom of the kettle. When settlement is finished, the wort is then passed through heat exchangers where it’s cooled down, aerated by the addition of oxygen and transferred into fermentation vessels for the final brew stage.
5. Fermentation
Our state of the art fermentation tanks (above) and the brewer adding our own unique strain of yeast
With the wort transferred into the fermentation vessel, our own unique strain of live yeast is added to the brew where it multiplies five times slowly converting the wort sugars into alcohol, natural carbon dioxide and heat.
The fermentation process takes four days where temperature is a critical factor. This is monitored by an automatic control system linked to thermometers and glycol cooling valves ensuring that a critical ferment temperature is maintained at all times.