Much like there are four main classical elements that are essential to life and that make up all the matter in the universe – earth, air, fire and water – there are four elements making up beer: yeast, (malted) barley, hops and water. Of course, this is a little oversimplified, and there are many other ingredients used in making the many beers available on the market today. Some beers, for example, use ingredients such as cassava, sorghum, and maize instead of – or in addition to – these primary ingredients. In the latter case, these are referred to as “adjunct ingredients”. Read on to learn a little bit more about the role each of the main beer ingredients plays in the brewing process. HOPS: THE ‘SPICE’ OF THE BEER “I like my water with barley and hops” – Anonymous Did you know that hops is one of the fastest growing plants in the world, growing about 15cm per day? It also has very specific requirements for where it can grow. That’s why the entire South African hops industry is located in one (relatively) small area outside George, where SAB pioneered South Africa’s hop growing industry nearly 100 years ago due to the area’s unique microclimate. And even these hop varieties have been specifically bred to thrive despite the mild winters and short summer days. (Hops prefer freezing winters and usually grow at a latitude that has on average three more hours of daylight in summer.) Hops are the dried female flowers of the hop plant (Humulus lupuls), and are responsible for providing stability, bitterness (from the resins) and flavour/aroma (floral and citrus notes, from the hop oils) to beer. Although only a very small amount is used for brewing (think ±40g of dried hops to make ±100 litres), it is crucial for creating the beer flavours that we know and love. YEAST: THE ‘FERMENTER’ OF BEER “Fermentation may have been a greater discovery than fire.” – David Rains Wallace Despite being one of the simplest forms of plant life, yeast is arguably the most important ingredient in beer-making process. Because it is responsible for the fermentation process, without yeast beer would not contain any alcohol. And this is true for drinks other than beer as well. Even the honey wine (!karri) made by the Khoisan in southern Africa used the yeast that naturally occurs in honey for fermentation. Yeast feeds off the sugars of the malty wort (the liquid extracted from the mashing process during brewing) to produce two essential characteristics of a great beer: carbon dioxide (fizz) and alcohol. What makes this single-celled fungus particularly interesting is that it wasn’t properly understood until French microbiologist Louis Pasteur proved that living yeasts were responsible for alcoholic fermentation in the late 19th century. For thousands of years prior to Pasteur’s discovery, yeast wasn’t even considered an ingredient in beer. But not all yeasts are created equal. There are hundreds of yeast strains available around the world, each imparting a somewhat different flavour. Brewers use different strains of yeast to create exactly the beer they want – everything from fairly neutral strains that create alcohol and do little else, to strains that yield different fermentations and flavours. Baker’s yeast vs Brewer’s yeast The yeast used for baking is not the same as the yeast used in beer making. Baking yeasts are usually more aggressive, allowing the bread to rise in the least time possible, while brewing yeasts tend to work more slowly, but can tolerate more alcohol. There are two main types of brewer’s yeast: top-fermenting ale yeasts, which have a history stretching back into ancient times, and bottom-fermenting lager yeasts, which were only perfected in the mid-19th century. Ale yeast works best in warm temperatures (15°C – 24°C), and creates a more robust-tasting beer that tends to be fruity and aromatic. Ales include bitter beers with a distinct, complex taste and aroma, that are served at slightly warmer temperatures (7°C – 12°C). Lager yeast performs best in cooler temperatures (3°C – 11°C) and creates lighter-tasting beers that tend to be extremely bubbly or crisp. Lagers are usually fresh, balanced in taste and aroma, and are served fairly cool (3°C – 7°C). Many brewers consider the yeast they use to be their ‘secret ingredient’, often fiercely guarding the identity of the strain. And depending on how the yeast performed, it is often re-used in new fermentations (one yeast cell buds three daughter cells during a typical fermentation) – an ingredient that recycles itself. Did you know: The strain of yeast we use to brew Castle Lager today is exactly the same as the one Charles Glass used at Castle Brewery back in 1895! MALT (MALTED BARLEY): THE ‘BODY AND SOUL’ OF BEER “Malt does more than Milton can to justify God’s ways to man.” – A. E. Housman In order to create the alcohol and carbon dioxide so integral to today’s beers, yeast needs to feed on sugars, which most often come from starches like sorghum, cassava and barley (Hordeum vulgare), with the latter being the most commonly used starch in modern beer production by far. Malt, or malted barley, is the main ingredient in most modern beers, and is responsible for the distinctive colours. In fact, all the colour in your favourite beer comes from the malted barley. Malting is a process that takes the hard, tasteless seeds of the cereal grain barley and – through carefully controlled soaking and drying in a kiln (or even roasting, depending on the beer) – produces the base used for the beer. Effect of malt on beer flavour The exact malting process used depends on the type of beer being produced. Black malts, for example, are super-kilned barley malts used to darken the colour (and flavour) of a beer, while the pale malts form the base for lagers, imparting both flavour and sweetness. Each beer has its own profile, so the malt used must be able to deliver the correct characteristics – those that will allow the yeast to ferment to the right beer profile. WATER: THE ‘INTEGRITY AND PURITY’ OF BEER “Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer.” – Dave Barry Last, but very definitely not least, in the list of essential beer ingredients is water, known in the brewing world as “brewing liquor”. This precious liquid is vital both for growing the other ingredients used to brew beer, and at several stages of the brewing process: as a cleaner and soaking medium in the malting process, and as a catalyst for enzymes during fermentation. The quality of water used in the brewing process is closely tied to the quality of the final product, with water “hardness” (the presence of certain minerals) being one of the most important factors affecting the final beer. These are the main ingredients we use in the brewing process. Find out what happens once the beer is brewed.