Welcome to our interactive tour of the Fuller's brewing process. This animation demonstrates the unique way that Fuller's produces its high quality range of beers and ales.

THE HISTORY OF BEER

Beer, and Bitter in particular, is a way of life in the United Kingdom. There are few images more quintessentially typical of the British Isles than that of a pint of bitter being drunk in a pub.

Beer has been around for centuries and had almost certainly arrived in Britain by the Neolithic period. Through the ages assorted marauding invaders have tried to make their own particular tipple predominate -- the Romans' wine, the Norman's cider -- but to no avail.

So beer it became and beer it remained -- brewed in the home, on the farm and most notably in monasteries where passing travelers and pilgrims could pop in for a refreshing pint before continuing on their journey. There were no huge brewing operations as we see them today until the introduction of refrigeration in the late 19th Century. However, there are records proving that brewing on some scale has taken place on Fuller's Chiswick site for over 350 years, making it the oldest brewery in London.

Brewing, like many other industries, involves many unfamiliar terms that can make a perfectly simple process sound baffling!

The four major ingredients of beer are water, malt, hops and yeast. An average daily brew of Fuller's flagship brand, London Pride, uses 750 barrels of water, 13 tons of malt, 242 lbs. of hops and 704 lbs. of yeast. All of this produces 640 barrels or 184,320 pints of London Pride. That's enough to give every spectator at a Wembley Cup Final three pints each. Possibly not a very good idea, but it does give you some idea of the scale the brewery works on!

MALT

Malt is barley grain that has been steeped in water to start its growth (germination) and then halted by heating or kilning. The germination process naturally breaks down complex molecules of starch, which then become sugars and ultimately alcohol.

As well as stopping germination, kilning also roasts and browns the malt, which adds color, and flavor to the beer at a later stage. For example, if malt is heavily roasted to a dark brown color it is called a "colored malt" such as "chocolate malt".

Chocolate malt contributes color and flavor to London Porter. Amber malt contributes color, sweetness and dryness to 1845 Celebration Ale. Crystal malt adds color and nutty, toffee, fruity notes to ESB and London Pride.

Fuller's used to have its own Maltings further down the Thames, but these were destroyed by a bomb during World War II, and since then malt has been brought in from outside British suppliers.

MILL

The mechanical breakdown of dry goods is known as milling. This increases the surface area so enzymatic attack is maximized in the presence of hot water to convert the starch to fermentable sugars. If extra cereals containing starch are added, the enzymes will convert this into sugar too. It is important to keep the husk of the malted barley grain as intact as possible because it forms a filter bed in the mash tuns. The milled cereal mixture is called grist. Grist is then transferred via conveyor to grist hoppers above the mash tuns.

WATER

The quality and type of water is of great importance in brewing. At one time, there were over 200 breweries in Burton-on-Trent where the well waters, which have a high content of Gypsum (calcium sulphate), are ideal for producing pale ales. However, breweries no longer need to rely on particular sources of water, because brewers can vary water composition to suit their particular needs. It is possible to produce a water similar to that found in Burton-on-Trent by a process known as "Burtonization".

Fuller's used to have an artesian well, but now draws water from the mains. Water entering the brewing process is known as "liquor." It is treated to remove hardness by heating and acid addition. The water used in the actual brew is only a small proportion of the total amount used by the brewer. An efficient brewery will use 5-7 pints of water to produce one pint of beer, the remainder being needed for heating, cooling and washing.

MASH MIXER

The grist is a concentrated source of starch and proteins, which must be converted into sugars and amino acids by enzymes in the malt before the mixture can be fermented by yeast. Hot liquor (156-160ºF) comes into contact with the grist in the "Steel Masher" to achieve a mash temperature of 149ºF in the mash tun.

MASH TUN

A porridge-like mash is formed with a bed depth of 1.5 – 2.0m in the mash tun. The mash tun has a false/slotted floor 5mm from the base of the vessel, and the mash sits on this for 55 minutes. The false floor is flooded with hot liquor before mashing starts to remove any air. By the end of the mashing period, the enzymes in the malt will have broken down the starch into fermentable sugars and the protein into amino acids. The sugars, amino acids and coloring matter will all have dissolved into the water. This sugar solution is called wort. The wort is separated from the remaining solids. The husk acts as a filter, removing particles as the wort drains away through the floor of the mash tun. To remove as much wort as possible from the mash, when the first solution has almost drained, more hot liquor is sprayed over the mash; this is called sparging.

HOPS

Hops is the ingredient that gives beer its characteristic bitterness. Hops started to be added to ales in the 15th Century both as a flavoring agent and also for their mildly antiseptic properties, which stopped the beer from spoiling. Hops are grown primarily in the southeast of England and Hereford and Worcestershire. Varieties used by Fuller's include Target, Northdown, Goldings, Fuggles, Challenger and First Gold. Different varieties have subtly different aromas, offering floral, spicy, woody or citrus tones.

Hops are grown on a network of supporting wires and the cones (flowers) are harvested each autumn. Only female plants bear hop cones. They are dried and can be used directly or as pellets. Hop pellets are concentrated from hop cones and used at Fuller's. In some beers a few hops are added to the final product in cask and this process is called "dry-hopping."

COPPER

The wort is transferred to the copper. Traditionally, this was a copper vessel, but in modern breweries it is made of stainless steel. Fuller's has two 380-barrel stainless steel coppers. The wort is boiled and the hops are added. Adding hops at the start of the boil is known as "kettle hopping." "Late hopping" is adding aroma hops late to the boil to give late hop characters. After boiling, the wort is passed through a whirlpool where the used hops and other waste material are removed. The solid matter collects at the center, and the wort is run off for cooling and pumping to fermentation vessels.

PARAFLOW

The wort is cooled quickly via a paraflow. This cooling removes small particles and prepares the wort for yeast addition. The paraflow is a heat exchanger made up of 100 plates with chilled liquor (<14ºF) on one side and hot wort on the other. This large surface allows the heat from the wort to heat up the liquor (thus cooling the wort itself), which returns to the liquor tanks for the next day brewing. The wort is cooled to 63ºF en route to the fermentation vessel.

YEAST

Yeast is a microorganism. It is an extremely important brewing ingredient, because different strains give different beers their distinctive and characteristic flavor. Yeast can feed on a variety of sugars, converting them into energy in order to grow and multiply. In the absence of oxygen, yeast obtains its energy from anaerobic fermentation in which sugars are converted into carbon dioxide and alcohol.

Each brewery has its own particular and unique strain of yeast. Samples of them are held in a National Yeast Collection so that should sudden disaster strike and all traces of Fuller's yeast be lost on site, a new batch could be cultivated from the stock strain.

FERMENTATION

Fuller's yeast is added (pitching) at 10 million cells per ml to the wort as it travels from the paraflow to the fermentation vessel at 63°F.

Air is added in-line or directly into the fermentation vessel at the start of fermentation. This is so the yeast can form materials needed for new cell membranes and walls.

The air is switched off and anaerobic metabolism by the yeast on the wort sugars continues to form alcohol and carbon dioxide. Many flavor compounds are also formed by the yeast as it utilizes the carbohydrates and nitrogen available in the wort.

Yeast will multiply fourfold during fermentation. The bulk is removed and sold for food production or for health foods as it is rich in vitamin B.

MATURATION / CONDITIONING/ FILTRATION

After fermentation, all Fuller's beers are centrifuged to remove any excess yeast. Beers for kegging or bottling go to "conditioning" at 50°F and beers for cask go to "maturation" at 43°F. En route to these individual departments, a small amount of yeast is re-introduced into the beer stream.

A period (5-7 days) of warm conditioning or secondary fermentation is allowed in which the yeast reduces buttery flavors and modifies green, grainy flavors to more rounded malty notes along with production of carbon dioxide. Beers from maturation are then ready for cask racking.

Beers in conditioning tanks are then cooled rapidly to 29°F to ensure residual protein comes out of the solution and can be removed during filtration. This produces "bright beer". Because bright beer has been treated to remove yeast and solids, it can be kept for much longer and is ideal for bottled beer that has a longer shelf life.

CASK RACKING

Beer from the maturation tanks is pumped to the racking tank for filling into the casks. Fermentable extract and yeast remains in this beer, so a secondary fermentation takes place in the cask.

Beer is run into the racking tank (auxiliary finings for protein removal are added). Casks are filled directly or via a racker under counter-pressure from a smaller tank, the Jack Back.

ESB is dry hopped (a nugget of compressed hop flowers is added to each container).

Isinglass finings (swim bladder of tropical fish) are added as the cask is filled. This forms a collagen net, which traps the yeast and brings it into the belly of the cask after it has settled.

Cask, keg or bottle? Glad you asked.

Fuller's beers are made ready for drinking from casks, kegs and bottles. Unlike a keg, a cask has two openings -- a keystone hole on the end and a larger shive hole on the side. The shive hole allows air into the cask while the beer is drawn from the keystone through a tap called an extractor. A cask conditioned beer is one that has undergone a natural, secondary fermenting in the cask. Cask conditioned ales may contain a naturally occurring sediment, which remains in the cask. These ales have similar shelf life compared to bottled conditioned ales.

A keg has one opening that is fitted with a valve. Opening the valve forces compressed gas into the keg, which in turn forces the beer to the tap on the bar. Unlike cask beer, keg beer has no sediment and enjoys a longer shelf life compared to casks.

Most bottled beers are ready to drink as soon as they are packaged. But some beers, such as Fuller's 1845, are bottle conditioned, meaning they contain live yeast in the bottle, which causes a second fermentation.