Brewing Process

Our Story

Brewing process

Ale is a natural drink made from hops, malt barley, yeast and water. From these simple raw materials, ale is brewed to many different recipes

Malting - pictures associated with: malted barley at Laphroaig.JPG (brewing)

Before you can brew with barley, it must undergo a process known as malting. The malting process simulates the grain's natural germination cycle. Under closely monitored conditions, malting companies wet the barley kernels and allow them to sprout. As the seedlings begin sprouting, the starchy insides of the kernels (or endosperm) begin to change. This modification causes the hard, starchy endosperm to begin to break down into natural malt sugars (maltose) that brewers later liquefy, during the mashing process. One of the important features of this process is the production of the enzymes brewers later use in the mashing process. And the maltose sugars, along with proteins and dextrins, contribute the color, flavor, sweetness, body, mouthfeel, and foam in the beer. (Mouthfeel can be defined as the textural qualities of beer on your palate and in your throat — viscosity, or thickness; carbonation; alcohol warmth; and so on.)

Only after the barley has undergone the malting process does it become malt, or barleymalt.

Malted barley is an incredibly complete and convenient package, seemingly designed exclusively for brewing beer. Each grain kernel contains carbohydrates (which eventually convert to sugar), enzymes (which do the actual converting), proteins (which provide yeast nutrition, mouthfeel, and head stability), and a husk (which, when multiplied by thousands, acts as the perfect natural filter bed through which you can drain the unfermented beer).

Very few commercial brewers — usually only the huge beer factories — do their own malting. Professional malting companies (also called maltsters) malt most of the grain for the brewing industry (including smaller commercial brewers and homebrew supply shops).


Here at GWB we buy in uncrushed malt, then we crush or crack it with two roller malt mill. Our malt mill can be set to different consistencies. The ideal crush for malt exposes all the endosperm as flour and leaves the husks intact. Picture- P9050144.JPG (brewing album)

 But in practice this is difficult to achieve. In order to expose as much of the endosperm as possible, the malt has to be crushed very tightly which leaves most of the husk material shredded. This can lead to stuck sparges and astringent off-flavors. Conversely, when the malt is milled too loosely the husks are preserved better but a considerable amount of the endosperm remains unexposed which will result in a loss off efficiency. Because of this the brewer needs to find a good compromise for setting the grain mill spacing. The malt mill sits above our Grist case from where the malt drops and fills it. Picture here (not yet taken)



The purpose of the mashing process is to extract the starch from the malt and convert it into fermentable sugars which will be converted by the yeast into alcohol and carbon dioxide.


After the malt has been crushed in the milling process it falls into the grist-case. This large container houses all the malt for the is delivered to the mashing area and pumped into a  large vessels known as mash tun. These vessels are surrounded by steam heating coils and are equipped with an internal agitator. Hot water is

added to the ground malt, typically in a ratio one barrel of water to 100 pounds of malt. Throughout the mashing process,

water facilitates the extraction of the starch from the grains and is the means of heat transfer driving the reactions. In som


cases, adjunct grains such as corn and rice are used to increase the amount of starch available in the mash. These are cooked separately in the cereal cooker and added to the mash tun. Heat is applied to the mash tun and the mixture is slowly agitated to create a thick slurry known as mash. The natural enzymes

present in the barley begin to break down the starches in the mash into simple sugars in a chemical process known as

saccharification. Some brewers will supplement the barley enzymes with additional proprietary enzymes to enhance the

saccharification process. These supplemental enzymes are added in a liquid form and are usually very expensive. Temperature,

holding times and pH are closely monitored during this process to maximize the conversion of the starch into sugars.

Concentration of the mash’s total solids (sugars,

dextrins, inorganics and proteins), measured in


Plato, is monitored to

determine when the mashing process is complete.

When the mashing process is complete and all starches have been converted to fermentable sugars, the mash is delivered to

the brewhouse lauter tuns to separate the extract-bearing liquid wort from the spent grain.

The grist is mixed with hot water (about 65°C) and left to stand for about 60 minutes. The enzymes in the malt break down the starch to release soluble sugars (glucose and maltose). At the end of mashing, the clear sugary solution (“wort”) is “run off” into an underback leaving the insoluble “spent grains” in the mash tun. The spent grains being collected by local farmers for animal feed.


The sweet wort is pumped from the underback into the copper and boiled (for 30-90 minutes) with hops to release the hop bitterness and hoppy flavours. The bitter wort is then cooled and aerated to dissolve the oxygen that the yeast will need at the start of fermentation


Yeast strain and fermentation are as critical to brewing as grape variety is to wine. Yeast is added to the cooled wort in a fermenting vessel. It feeds off the sugars and nutrients extracted from the malt, producing carbon dioxide and alcohol. When most of the sugars have been used up, the yeast becomes inactive and the fermentation is complete.


The final process takes place in the cask. The ale is “Racked” into casks with the addition of finings, which sink to the bottom along with any solids in the ale once the container is at rest. This results in a clear, bright “cask conditioned” ale. The secondary fermentation that takes place in the cask produces CO2, and this is what gives real ale its natural bubbles and fizz on the end of your tongue.

Great Western Brewery

Bristol Road




The Rising Sun

Ryecroft Road

Frampton Cotterell



  • Facebook
  • Instagram

©2020 by Great Western Brewing Company Ltd.