Brewing is a magical process that turns the principal ingredient - barley (fit only for feeding to animals in normal circumstances!) - into a wonderful beverage called BEER. Strictly speaking, 'ale' has no added hops, unlike 'beer' that does. Flavour and bittering components are included to make the final product more stable, interesting and enjoyable to drink. That's brewing in a nutshell. For a bit more detail, read on.
The first step in the process is to turn the starch in the barley grains into fermentable sugars. Moistened barley grains are encouraged to produce small sprouts before being kilned (heated) to stop them sprouting further. Luckily our maltsters do this bit of the process for us and the malt arrives ready crushed in 25kg bags on pallets. This is stored on a mezzanine floor in the brewery ready for use. We also keep the hops up here in 5kg vacuum packs.
On the day before a brew all the ingredients are prepared. First, the water is tested for calcium content and adjusted to our requirements by the addition of dilute acid and gypsum based dry treatment. Furthermore the water is now referred to as liquor. Second, the malt (mainly pale malt) is weighed out with the required amount of crystal malt (for mouthfeel and flavour), torrified wheat (for head retention) and roasted barley (for colour and flavour). These dry ingredients are known as the grist. Not surprisingly they are tipped into the grist case. A different grist is used for each beer and the stronger beers use more of it.
Other than freezing, the best way to preserve the freshness and aromas of hops is to vacuum pack them. So, guess what? - we use vacuum-packed hops that are weighed out into sacks ready for use the following day. We use a blend of hops in our beers with a different blend for each one - except Fuggle-Dee-Dum which is 100% Fuggles hops.
The final jobs are to clean and sterilise the fermentation vessel and the hot and cold liquor tanks are filled and set to heat up/cool down overnight.
Brew day! If all has gone well overnight we now have the two liquor tanks at the required temperature, the grist case full of the correct grist and a brewer (or two) with a vague idea of what to do.
The grist is allowed out of the grist case under gravity and is mixed with hot liquor in a mashing head on its way down into the mash tun below where this porridge-like mixture (mash) sits on its perforated false bottom. The temperature of the resultant mash is controlled by mixing the hot and cold liquor in the masher to achieve a temperature of 65 degrees centigrade. Varying this temperature up or down by a degree or so alters the proportion of unfermentable sugars (dextrins) and thus the sweetness and mouthfeel of the finished beer. The mash is left for an hour during which time the enzymes in the malt are activated and convert most of the starch contained in the malt into fermentable sugar.
The liquid wort (as it is now called) contained in the mash tun is drained off through the perforated false bottom and pumped into the copper. This takes about an hour during which time the remaining sugars are rinsed out by spraying the mash with hot liquor, a process known as sparging.
When sparging is complete the remaining solids are removed from the mash tun via a small door on the side and put into sacks. There is much competition among brewery staff to perform this task. Not. The sacks of spent malt are taken away by a local farmer.
As soon as the wort covers the stainless steel heating coil in the bottom of the copper, the gas-fired heater is switched on and starts to heat the wort. It reaches a vigorous rolling boil some two hours later.
As soon as the wort boils a charge of hops (known as copper hops) is added to the copper via a manway on top. These add bitterness to the finished beer. After 55 minutes boil, during which time the bitterness is extracted from the hops and the wort sterilised, a second charge (late hops) is added for the last 5 minutes of the boil and give the finished beer aroma and hoppiness.
The copper heating is turned off after the 1 hour boil and the hops settle on to the perforated false bottom (yes, another one) within. The hopped wort is then recirculated through the hop bed until it is seen to be bright in the sight glass.
It is then ready to be cooled and this is achieved by running it through a heat exchanger containing stainless steel plates. Cold water circulates across one side of the plates and the hopped wort on the other. This has the effect of cooling the wort and heating the cold water.
The cooled wort is pumped into the sterilised fermenting vessel (prepared earlier) and the hot water is pumped into the brewing liquor tank ready to be adjusted for the following day's brew.
When empty the copper is opened and the spent hops raked out into a wheelbarrow and composted as a mulch/soil conditioner. At the end of the brewing day all the equipment is washed down ready for use the next day.
The next requirement for this magical process is yeast. We use a fresh charge of dried yeast for each brew and this is added to the fermentation vessel as it fills at around 20 degrees centigrade. Shortly after the yeast is added to the hopped wort it starts to convert the sugar that we extracted from the malt into alcohol and CO2. The following morning there is a thick head on the fermenting beer forming a protective coating as it ferments. The CO2 is exhausted to atmosphere but the alcohol - which seems to be what people like in their beer - stays put and we carefully monitor its ABV (alcohol by volume), until it reaches the desired level. This is achieved by cooling the beer, which slows the process right down. The whole process takes 5 or 6 days until the finished beer is ready to be racked into the casks.
On the day before racking, the beer is pumped from the fermentation vessel over to the racking tank where it is left overnight for some of the remaining yeast to drop out of suspension. A small amount of yeast is carried over into each cask to allow the beer to ferment inside it. The CO2 created in this secondary fermentation puts a sparkle or condition into the beer - and makes it 'cask conditioned'.
The following morning the beer is run into the casks (which have been sterilised earlier on our cask washing machine) through the racking cock. This fills the casks from the bottom preventing air being mixed with the beer, which would ruin it. Finings are added at this point to enable the beer to drop bright at the pub by settling out the remaining yeast.
There is a saying that "beer should be godly. It should spend at least one Sunday in the fermenter" - ours does, you'll be glad to hear. After racking the beer then goes into the cold store where it stays for a minimum of one week at 12 degrees centigrade to allow conditioning to take place before its onward journey to our customers.