Brewing Terms

The range of technical details involved in brewing beer is huge and covers everything from metallurgy to biochemistry. We think that before you start your brewing mission, you should brush up on some terms you might come across.

Chemical and Biochemical Concepts

A good grasp of the complexities of brewing needs you to get to grips with various terms and processes. The list of terms below may appear to be highly technical jargon, but these terms are necessary to explain the complex concepts involved in brewing.


This is a way of gauging the acidity or alkalinity of a solution. The H signifies H+, which refers to hydrogen ions; these are protons which carry a positive electrical charge. The more H+ ions, the more acidic the solution, a more alkaline solution yields a soapy taste. The pH scale is logarithmic, each full step signifies a tenfold increase over the previous step.

Neutral pH is at 7, representing neither an excess nor lack of H+ ions. Higher than 7 signifies an alkaline solution while below 7 signifies an acidic solution.

The pH scale is helpful in calculating the acidity or alkalinity of the mash, wort or beer

Wort pH Scale


Two or more atoms bound together in a stable configuration through electrochemical bonds.



An ion is an electrically charged atom or molecule. Water, the key component of beer contains mineral salts such as carbonate or calcium, when these mineral salts dissolve in water they break apart into their separate ions. These dissociated ions can be influenced in numerous ways to reach the required water chemistry for a specific beer.

Mineral salts break down into their individual ions when dissolved in brewing water, this can be manipulated to achieve a desired water chemistry needed to brew a particular type of beer.

Mineral Salts Becoming Ions


The capability of particular molecules to absorb acids or bases, these molecules are usually amphoteric (both an acid and a base). This is a vital element of mash chemistry, as many chemicals in this procedure have strong buffering abilities.



If matter is to be converted from one chemical state to the other, it needs to experience a chemical reaction. Going into a chemical reaction the reactants have particular energy states, the reaction results in these energy levels being altered, therefore changing the reactants. In order for this to happen energy needs to be put into the system. It helps to think of this energy as a mountain: On one side is before the reaction, the other side is afterwards. To get over the mountain, a push is required to get up the hill so it can roll down the other side afterwards. Certain reactions, such as the conversion of starch molecules into sugar, require a great deal of energy to be put in in order to complete the transformation.



Enzymes are specialized proteins which are often referred to as biological catalysts; they aid chemical reactions by reducing the energy requirement for a reaction to take place. Enzymes have huge effects on reactions, reducing the required energy by a significant margin. There are thousands of different enzymes involved in brewing alone. Life as we know it would be unfeasible without them.

Each enzyme has an optimum temperature, pH, water concentration, and other parameters that affect its efficiency. Enzymes are named after the chemicals they affect and usually end in “. Amylase, one enzyme which splits barley starches which are called amylose and amylopectin, hence the name.



A polymer is an organic molecule which is made up of hundreds or thousands of smaller subunits. They are universal in living organisms. In brewing we are most interested in proteins and starches.



This is a huge category of compounds built from five- or six-sided ring-shaped molecules. The basic forms in this class monosaccharide sugars, for example glucose or fructose. Two sugar units joined together are known as a disaccharide; in brewing, this is usually maltose. Larger chains are called as oligosaccharides, and when the chain grows bigger than around ten units, it is referred to as starch.

Some sugars and other common carbohydrates involved in brewing include:


A simple sugar unleashed during the malting process. Glucose makes up less than 10% of the extract.


A two-unit sugar, this is the key fermentable sugar in wort, formed during the mashing phase, this sugar makes up less than 10% of extract.


A three-unit sugar, a small wort component. Only fermentable by lager yeast.


A four-unit sugar un-fermentable by any form of brewers’yeast.Maltotetraose


Larger sugars (containing up to 10 units), un-fermentable by any form of brewers’ yeast. The amount of dextrins present in the final beer depends on the brewing process.



Longer straight-chain (amylose) or branched (amylopectin) carbohydrates. Beer usually has no starch present.


Amino Acid

A group of nitrogen-containing molecules which are the building blocks of proteins. There are only around 20 different amino acids in living organisms. Brewers need to be aware of them as they are a vital aspect of yeast nutrition.



A specific group of polymeric molecules made up of amino acids. They have a role to play in most biochemical processes, from enzymes to signalling chemicals.