Beer : Health and Nutrition

The Basics of Malting and Brewing 55
Hops, perhaps even more so than barley, are prone to disease and infestation (Neve
1991). Accordingly they almost invariably demand some form of protection during their
cultivation, with the same considerations as given above for barley.
The gross composition of hops is shown in Table 3.3. One advantage to the use of
extracts of hops is that they have a somewhat lower nitrate content than the parent plant,
nitrate presenting a potential cancer risk by comprising a precursor of nitrite. Even so,
the contribution of nitrate to the daily human intake coming from any form of hops (or
indeed beer) is extremely low in comparison to other sources.
Water
As the vast majority of beers are more than 90% water, its composition is of critical
concern to the brewer. Any water that will end up in the beer or that will be in contact
with tanks, pipes, etc. through which the process stream passes, must be of the highest
chemical and microbiological quality. The water must ful l all legal requirements both
chemically and microbiologically as well as satisfy the brewer’s standards for clarity and
lack of colour, taste and smell. Most, if not all, countries have their regulations concerning
the quality of water. In the UK water quality is in the province of the Department
for Environment, Food and Rural Affairs (http://www.defra.gov.uk/environment/
water/index.htm). In the US potable water must satisfy the National Primary Drinking
Water Regulations established by the Environmental Protection Agency (Table 3.4).
Additionally there are National Secondary Drinking Water Regulations (Table 3.5).
The latter are non-enforceable guidelines (though states may choose to adopt them as
enforceable standards) regulating contaminants that may cause cosmetic effects (such
as skin or tooth discolouration) or aesthetic effects (such as taste, odour or colour).
The World Health Organization publishes Guidelines for Drinking Water Quality (http:
//www.who.int/water_sanitation_health/).
Table 3.3 Composition of hops.
Component % of total dry weight
Resins 17
Essential oils 0.6
Tannins 4.5
Monosaccharides 2.5
Pectin 2.5
Amino acids < 0.2
Proteins 17
Lipids and wax 3.5
Ash 1
Cellulose, lignin, etc. 45
Source: based on Hough et al. (1982).