What goes into beer?
yeast, malt, water and hops
Yeast is a single-cell organism, a type of fungus. It eats simple sugars and, in doing so, creates carbon dioxide and alcohol as by-products, together with a range of other compounds that together contribute flavor and aroma to beer.
There are two main types of yeast, ale yeast and lager yeast. Ale yeasts are often referred to as top-fermenting because of where they appear most active in the fermenter, while lager yeasts are regarded as bottom fermenting. Ale yeasts tend to ferment best at warmer temperatures (above 15°C) while lager yeasts will work at much colder temperatures.
With the huge popularity of light lagers, yeast has tended to be forgotten about as an important ingredient. With most pale lagers, ‘crisp’ and ‘clean’ are most commonly used to describe the flavours, when in fact these adjectives are really describing the lack of yeast flavour because lager yeasts ferment much more cleanly than ales. In ales the flavours and the aromas produced by the yeast are important aspects of the beer. Yeast can contribute characteristics that can be described as fruity or spicy, but can include such aromas as farm yard and horse blanket, not pleasant sounding but acceptable in the right beers!
To naturally create alcohol, you need a sugar source as well as yeast. In cider the sugar comes from apples, in wine from grapes. In beer the sugar can come from a variety of grains, primarily barley but also wheat and others. While fruit sugars are simple and immediately fermentable, the starches in grain need to be broken down into simple sugars, more readily digestible by the yeast. The process by which this commences is called malting. Malting creates the enzymes that are needed to break down the sugars and starts the process of breaking down the barley starches into simple sugars. The breakdown of these starches commences in the malting plant and is continued in the brewery.
The first part of the malting process involves germination where the maltster takes the grain and steeps it in water. After about two days, the germination starts and the enzymes needed to break down the starch are produced. The germination is then stopped by drying out the malt by kilning it. The way in which the drying out is done and the temperatures used can produce a wide range of malt types that in turn are used to create a wide range of beer styles. Just as cooking sugar on a stove causes the sugar to change to toffee and roasting coffee beans sees them develop stronger flavours, the kilning of these specialty malts leads to the development of darker colours and more intense flavours in the grain. The range of flavours can include toffee, caramel, biscuit, stewed fruit and toast through to roasted flavours including coffee.
While mainstream brewing came to treat hops as something of a one-dimensional ingredient used to impart bitterness, the hop has come to be celebrated by the craft brewing renaissance. Hops are the flowerlike cones of a climbing vine. In the middle of each hop cone are little glands that contain resins and oils. While these can contribute flavour, aroma and bitterness to beer, they are not soluble in water. They need to be boiled as part of the brewing process in order for the resins to dissolve and impart their bitterness.
The longer the hops are boiled, typically around 45-90 minutes, the more bitterness they will lend to the beer. Added later, they contribute aroma to the beer. In many craft beers hops are added after the boil, during fermentation, or even during maturation, in a process known as dry hopping. This contributes substantial flavour and aroma to beers without increasing the bitterness. While beer itself dates back beyond the beginnings of civilisation, hops are a relative newcomer to the brew having only been used for the last 1000 years. While many different herbs and spices have been used in beer, hops were popular because they also have a preservative effect on beer.
There are a wide range of hop varieties, each with their own unique characteristics and each adds something different to a beer. The hop variety used is often a selling point for many craft beers. Some hops are highly processed to create hop extracts that can be used for a variety of reasons in beers from stabilising foam to preventing light strike in beers packaged in light green and clear bottles.
Water is a vitally important ingredient in beer, but sometimes is highly regarded for the wrong reasons. The chemistry of the water – the levels of dissolved salts and minerals – is critical to the successful brewing of many beer styles. In a pre-industrial age before we had a firm understanding of chemistry, brewers made beer according to the water they had available and brewed style to match it. Modern brewers can create the precise water profile they want irrespective of their location to perfectly match the beer styles they want to brew. Water needs to be high quality, free from contaminants and smells. Today most brewers filter their water before adding the salts and minerals, if needed, to create the right water chemistry for their chosen beer style.
Adjuncts and other ingredients
While malted barley is the most common sugar source for brewing, a number of others can be used as well. Corn, rice and cane sugar can all be used, generally to lighten the body and flavour of beer. While craft brewers generally avoid adjuncts, many have begun to use – or rediscovered uses for – a variety of herbs, spices and non-traditional ingredients to accentuate and complement some of beer’s naturally occurring flavours. These can include spices, honey, fruit, coffee and chocolate.
Article Credits: CBIA