Malt, Hops, Water and Yeast are the four key beer ingredients. They are all essential and bring their own unique characteristics to beer flavour. Malt is the source of the sugars that are fermented by the yeast to produce alcohol. We use hops to contribute a range of flavours, from intensely tropical to piney and spicey. Water makes up over 90% of beer and its mineral composition can alter how beer flavour is perceived. A better understanding of these ingredients will help you to have a bit more fun and flexibility with your brewing. Want a darker beer? Look to the specialty malt. Don't think your NEIPAs are juicy enough? Maybe use your hops later in the boil. This article will give you the foundations to a good understanding of the main ingredients in beer.
What is malt?
The malt we use in brewing is primarily barley grains that have been transformed in the malting process. It provides the starch, enzymes, amino acids and other essential elements for making beer. Many of these elements are required to feed the yeast and produce the alcohol in beer.
Types of malt
Base malts are a class of malt that contain high levels of starch and make up the majority of fermentable material in most beer recipes. They are normally lighter coloured, for example the Pilsner Malt and Ale Malt used to make light coloured lagers and pale beers. They can range to darker and more flavourful malts like Munich which can be used alone or in conjunction with other base malts.
Specialty malts are used on top of base malts to craft the colour and flavour profile of the beer. A class known as caramel malts can be used to contribute flavours ranging from a light sweetness to dark fruits like raisins and figs. Roasted malts are the darkest class which give the characteristic coffee, roast and chocolate flavours to stouts and porters. Only small amounts are needed to drastically darken the colour of a beer.
The malting process
The malting process is essentially the first step of brewing, however it happens at a malting plant rather than the brewery. The process begins by taking raw barley after the harvest and steeping it in water several times to increase the moisture content of the grain. The steep simulates the natural growth cycle of the barley and 'tricks' it into growing.
Germination is the next step where the maltster carefully controls the growth conditions of the barley. Changes within the barley, like breaking down of its proteins and cell walls and the creation of certain enzymes are the key changes required by the brewer.
The maltster then halts the growth and dries the barley by slowly heating it in a kiln. The time and temperature the malt spends in the kiln is used to produce a wide range of malts. For example, a shorter time in the kiln at a lower temperature is used to produce light coloured malts. Longer times at higher temperatures essentially 'toasts' the malt much like a toaster toasts bread. The malt aroma wheel from Weyermann is a great illustration of the range of flavours we can get from malt.
Brewing with malt
After deciding on the malts we want to use in our recipe we mill the malt. Milling cracks open the grain and makes the starch inside easier to extract. Milled malt is mixed with hot water at a specific temperature in the 'mash'. The starches are extracted from the malt and into the water to make a sugary liquid known as 'wort'. The malt's own enzymes will break down its unfermentable starches into simple sugars which can be fermented by yeast. When all the available starch is extracted from the grains, the wort can be separated and the grains are discarded. Big breweries often donate their 'spent grain' to farmers as nutritious livestock feed. Many home brewers will use spent grain as chicken feed, for making dog biscuits or as compost.
What are hops?
Hops are the flowers from hop plants (Humulus Lupulus). They are used heavily in brewing for their flavour, aromatic and preservative qualities. Hop flowers - also called cones, are harvested once a year and then typically dried and processed further into pellets and extracts to be used by brewers for the whole year.
Types of hops
The traditional hop varieties used for brewing originate from several regions in Europe - they are known as 'noble hops'. The four noble hop varieties are Hallertauer Mittelfrüh, Spalt and Tettnang from Germany, and Saaz from Czech Republic. These varieties were used predominantly in European lagers to impart bitterness and subtle flavours such as spice and floral.
A rich history of hop breeding all over Europe, America and even Australia and New Zealand has drastically expanded the number of hop varieties available to brewers. We can trace the lineage of many modern hops back to traditional varieties. Selective breeding means that many newer varieties have far more bittering potential, meaning breweries require less hops for the same amount of beer. Varieties developed for their aromatic qualities are undoubtedly a massive driving force in craft brewing today. They are responsible for the unbelievable fruity aromatics in Pale ales and IPAs which we can't get enough of.
While using whole cone hops seems like a romantic idea, brewers have found that more processed hop pellets and extracts are a far better way to use them in brewery. They are less bulky, easier to handle, less prone to staling and drastically reduce beer losses, resulting in a far more sustainable business.
Brewing with hops
We add hops at various stages in the boil and fermentation to get the level of bitterness and aromas desired for the beer. Some beer styles, like a European lager have minimal hop aromatics and a small amount of bitterness. We may choose to only add a small amount of hops to impart some bitterness for these beers. At the other end of the spectrum are hugely aromatic IPAs. These beers benefit from multiple hop additions through the boil and fermentation to achieve their flavour profile.
The bitterness in beer largely comes from the isomerised alpha acids formed in the boil. Hops contain the precursor alpha acids at varying levels. Many varieties have been bred to have high levels of alpha acids - we generally choose these for bittering as it allows us to use fewer hops to achieve the same level of bitterness. The isomerisation of alpha acids in the boil requires time. Bittering hops are therefore added at the start of the boil. Many craft brewers cite IBUs (international bittering units) on their packaging as a measure of the bittering compounds in their beer.
Hop oils make up only a tiny fraction of the hop cone, but their impact can be significant. A single hop may contain hundreds of aromatic compounds, however a few of these make up the majority of the oil fraction. Some key oils are mycene (piney), linalool (orange, floral), citronellol (citrus) and geraniol (rose, geranium). Hugely popular modern hops varieties like Citra, Mosaic and Strata are favoured for their high levels of some of these desirable aromatics. The aromatic compounds in hops are quickly reduced when they are boiled. For this reason they are typically added right at the end of boil, often when the boil is finished.
Hops added to the fermenter during or after fermentation are known as the 'dry hops'. The cooler temperatures allow more of the hop oils to remain in the beer resulting in a more aromatic beer. While dry hopping is not new to the brewing industry, craft brewers today are pushing the boundaries of dry hopping using immensely more hops and often more than one addition to produce the exceptionally fruity and tropical beers welcomed by beer lovers.
The historic importance of brewing water
While water may seem like a neutral and somewhat unimportant ingredient, its impact on the development of beer styles around the world cannot be understated. It is the reason many regionally unique beers popped up in the centuries before more advanced water treatment was common in breweries.
With water making up over 90% of most beers, the minerals in the breweries water source have consequences throughout the brewing process. The historically high mineral waters of Dublin were found to be well suited for brewing stouts, while the water in Pilsen which is relatively devoid of minerals led to the development of the pale lagers known as Pilsner in the 19th century. Likewise, the calcium sulphate rich brewing water are a defining characteristic of the Pale Ales from Burton-on-Trent.
Brewing water today
Modern approaches to water in brewing are vast. Much like historic breweries, some brewers embrace their native water source and make beers which suit their water. Some breweries are blessed with excellent water sources which need minimal filtration or manipulation of minerals to brew great beers. Others may prefer to exercise a significant level of control by using filtration and mineral additions to improve substandard brewing water or to achieve more consistent brews.
What is yeast?
Without yeast, there would be no beer. Brewer's yeast is a living organism that converts the sugar from our malt into alcohol and an array of other flavour compounds. The yeast we use typically fall under two species - Saccharomyces cerevisiae, also known as ale yeast and Saccharomyces pastorianus, also known as lager yeast. Within each group are number of strains for brewers to choose from which will produce markedly different beers.
Ale yeast is usually fermented at warmer temperatures and will finish in 2-3 weeks. Ale strains are by far the most common used by craft brewers, but carefully choosing a strain is essential to get the desired flavour outcome as ale strains may impart stronger flavours to the beer. Perhaps the best example of this is German wheat beer yeast, which produces its characteristic banana and clove flavour profile. English strains tend to produce more fruity beers from the esters they excrete. Similarly, Belgian strains are high in fruity esters but may also produce spicy phenolics. Clearly, regionality plays an important role in choosing from historic ale strains. In modern craft brewing, neutral-flavoured ale yeast which played an important role in the rise of clean American-style pale ales and IPAs in recent decades.
Lager yeast ferments at cooler temperatures than ale yeast. The cooler conditions mean that lager fermentations take a bit longer but are usually more flavour neutral than ales. These characteristics make lager yeast the go to for those huge breweries producing the inoffensively flavoured pale lagers which dominate the world beer market. Despite the stigma attached to lager in the craft beer world, you don't need to look past Germany and the Czech Republic to find many exceptional styles of beer brewed with lager yeast.
Hopefully your newfound knowledge about the ingredients you brew with makes your brewing journey a more interesting one. The ingredients are just the start. Our upcoming articles will help you to round out your understanding of brewing with detailed explanations of all aspects of the brewing process as well as tips and tricks to make brewing even more fun.