Tastings School - One lump or two?

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One lump or two?

It has been suggested that there was room in BOTW for a little more technical stuff. So pay attention, here comes the science bit: Daniel Cooper reports on the use of sugar in brewing.

Yeast ferments sugar to produce alcohol – that is the basic biochemical process that our ancestors harnessed to produce our favourite alcoholic beverage. But there’s much more to it than that...

The sugar that the yeast requires to produce alcohol in beer is typically derived from a cereal source, usually malted barley, and the brewing process has evolved to facilitate the conversion of cereal starch into sugar. But for many brewers fermentable material can also come from cane or beet sugar in addition to barley malt. However, in some circles, sugar is given short shrift as it is wrongly perceived as just a cheap form of fermentable material.

The truth is that some of the characteristic flavours that we associate with many of the world’s greatest beers owe a lot to the use of sugar.

It is thought that the pleasant sweetness of sugar was first discovered by the indigenous people of Polynesia around 20,000 BC. However, it was not until much later, in India, that the first crude sugar was produced by extracting the sweet juice from sugar cane. In 510 BC the Emperor Darius, of what was then Persia, invaded India where he found “the reed which gives honey without the intervention of bees.” When the Arabs invaded Persia in 642 AD they learnt how sugar was made and, as their expansion continued, established sugar production in other lands that they conquered, including North Africa and Spain.

Sugar was introduced to Western Europe as a result of the Crusades in the 11th century AD. When the Crusaders returned home they brought with them stories of a “new spice” and its pleasing sweetness.

The first sugar was recorded in England in 1099, and subsequent centuries saw a major expansion of western European trade with the East, including the importation of sugar. It is recorded, for instance, that sugar was available in London at “two shillings a pound” in 1319 AD. This equates to about £50 per kilo at today’s prices so it was very much a luxury item and rightly earned the title of ‘white gold.’ Because of the value of the product, industrial scale sugar refining was quickly introduced. In the UK the first sugar refineries were established in London in 1544, and by 1750 there were 120 sugar refineries operating in Britain – many of these were associated with breweries. The output at this time was small at only 30,000 tons per annum. By 1876 the number of refineries had increased to 300. Contrast this with the modern industry where, in 2006, the UK had three sugar refineries in operation and global sugar production was estimated to be 147.7 million tons. However, of this huge tonnage only a small proportion is destined for the brewing industry.

There are a bewildering array of specialist sugars and syrups available to the brewer and each can impart a unique flavour on the beer that is brewed. The manner of processing the sugars (the degree of refining, hydrolysis or caramelisation) will dictate the amount of flavour and colour the sugars possess and therefore their contribution to the flavour of beer.

So why do brewers use sugar? Some might argue that the main motivation is financial. But this denigrates the distinct advantages that sugar brings to the brewer. Sugar has an impact on the mouthfeel, body and foaming properties of beer, but it is its role in producing some of the characteristic flavours of beer and the ability to control their production that makes sugar such a useful ingredient.

Beer flavour is essentially the way it is because of what the yeast ferments (sugar), what it excretes during fermentation (typically flavour compounds such as fruity esters), and what it does not touch (for example bitterness), so it is possible that, by controlling the type of sugar fermented, brewers can greatly influence what is excreted and, therefore, the flavour of their beer.

Much of the sugar fermented by brewers’ yeast comes from malt. However, malt is a natural product and the brewing process itself can lead to wort with different sugar compositions from brew to brew, and this can result in perceivable changes in the flavour of the beer. But with the addition of sugar brewers can iron out those inconsistencies and exert greater control on the fermentable material in the wort.

Sugar impacts on beer flavour through the obvious route of fermentation, but there are a number of other reactions involving sugars which occur during the brewing process and these also have a major impact on beer flavour.

The clearest example of this is caramelisation, the reaction of sugars by heating to produce the colour and flavours that are associated with its formation.

Caramel is an important source of both flavour and colour in the food and drink that we enjoy. In fact there is ample evidence to show that the colour of beer has the ability to shape our preference; visual appeal is an important aspect of beer and has a major influence on the way flavour is perceived. In simple terms if you darken the colour of a beverage people will tend to rate the flavour as being more intense.

Another important contributor to beer flavour, where sugars are essential, is the Maillard reaction. Interaction between sugars and amino acids (the building blocks of proteins) in the presence of heat will lead to a wide array of flavours. For example glucose cooked with certain amino acids, will result in the formation of baked, butterscotch and caramel flavours. Repeat the same process with a sugar like fructose and a range of meatlike flavours will be produced.

Potato crisp manufacturers use just this type of mechanism to create the meaty flavours found in beef and smoky bacon crisps, and the same process occurs in beer during wort boiling. Therefore by using combinations of different sugars brewers can create beers with distinctive flavours.

At this point the impact of sugar on beer flavour has largely been due to the processes up to and including fermentation. Traditionally, after fermentation brewers use sugar for priming which they add to unfined beer when filling into cask. By adding priming sugar to the cask brewers achieve more controlled secondary fermentation and therefore a better conditioned beer. However, with a flourishing bottled beer market brewers have started experimenting with novel flavours (think vanilla, peach blossom and elderflower) and have found that by using different sugars those added flavours gain better definition leading to a balanced, wellrounded beer.

Finally sugar is casting off its ill-deserved image of a cheap ingredient as an increasing number of companies are brewing beers which use specialist sugars and syrups such as Demerara sugar, maple syrup and honey to create both an interesting flavour and story – all of which helps to sell their beer.

There are a number of beers in the marketplace that use organic and fairtrade sugars that have great resonance with the consumer. Today’s brewers are looking for a ‘natural alternative’ which will gain greater appeal with drinkers.

With such developments occurring in the brewing industry perhaps it is time to take a fresh view of sugar and the role that it plays in the world’s great beers.