Applications of natural ingredients in alcoholic drinks - Natural Food Additives, Ingredients and Flavourings - page 356

What is defi ned as 'natural' varies between countries (see Chapter 1), although
defi nitions and labelling requirements are in general more liberal for alcoholic
beverages than for other foodstuffs. Within the alcoholic drinks industry, the
European Union (EU) concept of natural with regard to the ingredients of emulsion
liqueurs is especially liberal. In other areas, particularly concerning fl avours, the
defi nition is sharper. For example, in the EU, only caramel E150a is classed as a
natural caramel fl avouring, but as colourants, all four caramel categories (E150a-
150d) are regarded as natural.

16.2 Flavouring agents and colorants
16.2.1 Beer
Consumer beer tastes have altered markedly in recent years and today there is a
myriad of naturally 'fl avoured' beers that utilise aroma-contributing materials
other than the four traditional raw ingredients: water, cereal, hops and yeast.
Once malt has been 'mashed' in hot water (liquor) to convert the starch into
fermentable sugars in the brewery to produce 'wort', it is boiled and a source of
hops is added. This boiling stage is a critical aspect in beer production since
bittering substances (resins) and aroma compounds (essential oils) are extracted
from the hop fl ower or cone - originating from the female hop plant ( Humulus
lupulus ). Although hops were cultivated in Babylon as far back as AD 200, there is
no record of their use to make beer until around 1079 and their value as a raw
material for reasons of fl avour and preservation of alcoholic beverages was not
recognised until the twelfth century (Moir 2000). To meet the demands of the beer
brewing industry, hops are grown widely throughout the world. The success of
this perennial climbing plant is that it thrives in temperate climates; therefore
large yields are produced annually by Germany, US, Russian Federation, Czech
Republic, UK, Slovenia and Poland (McKay et al. 2011a).
Extractable hop resins and oils consist of numerous terpenoid or norisoprenoid
natural components (Fig. 16.1). The phenolic norisoprenoids, commonly known
collectively as α -acids and β -acids (sometimes referred to as just 'alpha'), are the
principle source of bitterness whereas monoterpene and sesquiterpene hydrocarbons
and their oxygenated derivatives provide the main source of aroma (Fig. 16.1).
Table 16.1 details typical α -acid and β -acid compositions alongside typical
aroma description, aroma compound composition and fl avour intensity for many
internationally harvested hop varieties. Cohumulone is commonly regarded as the
most aggressive bittering compound of the three main α -acids ( Fig. 16.1 ). This is
especially the case when the addition of hops takes place towards the end of the
boil ('late hopping' - the technique of adding hops to the 'copper' or kettle/boiler
in the last 5-10 minutes of the boil).
Hop varieties can generally be divided into categories according to their α -acid
content. Low (∼5%) α -acid varieties (often referred to as aroma or noble varieties)
include Cascade (US), Crystal (US), Goldings (UK), Fuggles (UK), Hallertau
(Germany), Liberty (US), Mount Hood (US), Saaz (Czech Republic, Germany)

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