versa, or from the West to the East. This massive rise in exports has only been possible because of the considerable improvements in the technical quality and particularly the stability of the product sold. ‘It's a great wine to drink locally but it doesn't travel’, an often heard expression when visiting wine regions in the 1970s and 1980s, is but a distant memory today. Microfiltration and ultrafiltration using membrane technology have been important tools in ensuring clarity and stability of the product, particularly in the case of the output of large producers. Other membrane processes, including reverse osmosis (RO) have enabled producers to achieve product of reasonably consistent quality and in styles that the marketers and gatekeepers believe to be popular with a wide audience, including those who were traditionally not wine drinkers.
Several ‘new’ markets have emerged in the last decades, particularly Asian countries: in the last few years, sales in China have surpassed the wine industry's expectations, especially for so‐called ‘fine’ wines, although, at the time of writing, this market has been contracting. The interest amongst wine lovers in the qualities and differences in styles in wines produced around the world is also high, as evidenced by the proliferation of wine societies and attendance at tutored tasting and other wine events, the growth in wine ‘tourism’, and the plethora of blogs and other Internet and media discussions. Annual global wine sales are estimated to amount to 246 million hectolitres, the equivalent of nearly 33 billion 75 cl bottles [3]. The diversity of retailers selling wine, declining for many years, has recently increased. The typical consumer of everyday wines is most likely to make their purchase in a supermarket rather than in a specialist outlet, but the Internet has been the salvation of independent merchants, providing a relatively inexpensive marketing vehicle and access to a national or even international customer base. Many of these outlets offer high quality wines from small, individualistic producers and, in some cases, the production operations are ‘crowd‐funded’ by enthusiastic and loyal customers.
The quality and style of wines from any region, or any producer, however small or large, will not be totally consistent from vintage to vintage – indeed it is these variations that makes individual wines so exciting to wine lovers. In other words, the quality properties of the finished product are not precisely predictable, unlike the product of other drink production technologies [4]. There is constant debate how much winemaking is considered to be an art or science. However, there is no doubt that the use of modern winemaking techniques has led to wines moving closer in style [5], and this is decried by both passionate small producers and serious and educated wine lovers. Certainly the use of technological equipment has led to less incidences of some faults and flaws but paradoxically has also contributed to the increase in others.
Although almost all ‘fine wines’ are bottled at source (usually at the winery but sometimes elsewhere in the region of production), there has been an increase in the last decade in shipping ‘everyday wines’ in bulk and bottling at destination. In fact this was commonplace until the 1970: cheaper wines were often transported in ‘SAFRAP’ (lined mild‐steel containers) or even ships' tanks, and of course wine had been transported in barrels for many centuries. The return to bulk shipping for inexpensive wines has been largely driven by economic factors, together with the need to be seen to reduce the environmental impact of transportation. There are other pros and cons to bulk transportation, particularly from a quality perspective. International Organization for Standardization (ISO) tanks and flexitanks are the two most widely used transport containers, and wines may become tainted from poorly maintained or cleaned ISO tanks, or the ethylene vinyl alcohol (EVOH) copolymer liner of flexitanks, although such instances are thankfully very rare. There are historic incidences of wines being tainted with naphthalene on journeys from Australia to Europe. Flexitanks may also permit some undesirable oxygen ingression, albeit at a very low level – the permeability of the material has decreased considerably since the 1990s. As flexitanks are generally ‘single‐use’, contamination from previous contents is not usually a problem, but the disposable nature perhaps does not sit well the purported environmental advantages of bulk wine shipping. A defective seal on an ISO tank or the use of a flexitank material that is highly permeable could allow oxygen ingress leading to degradation of the entire contents. Wines to be transported in bulk will require adjustment and stabilisation before their journey, and often again prior to packaging at destination – the latter operations being outside of the control of the producer, who may nevertheless bear the brunt of any fallout resulting from product deterioration, or the manifestation of faults or flaws. On the positive side, temperature variations during transport are very often less for wines in large tanks, and the standards of bottling at a dedicated plant at destination may be higher than those in some wineries.
1.4 The Possible Impact of Some Fault Compounds Upon Human Health
Most of the faults discussed in this book, however unpleasant they may be from an organoleptic point of view, are not generally harmful to human health, at least at the concentrations in which they may be found in wine. Wine has a low pH and pathogens harmful to humans will not generally grow in the product (although we should remember that every year somewhere in the world people die as a result of consuming ‘fake’ wine). There are, however, some compounds of microbiological origin that may be found in wine that have been shown to be potentially harmful to humans. The most important of these are biogenic amines, ochratoxin A and ethyl carbamate. Ethyl carbamate is classified as ‘a probable human carcinogen’ (Group 2A) by the International Agency for Research on Cancer (IARC) [6], and several countries have set limits for its concentration in wine. Biogenic amines are toxic at high concentrations, and some people have an intolerance at the levels very often found in wine. Ochratoxin A is a known carcinogen in some animals and a suspected human carcinogen by IARC (Group 2B) [6]; accordingly limits to its concentration in wine have been set by the European Commission (EC) for member states of the European Union (EU) at 2 μg/l [7]. In addition, some chemical compounds which may be found in wine can be harmful, particularly phthalates that can be hormone disruptors in humans. Their presence in wine is always due to contamination from an external source, such as the epoxy resin lining of concrete fermentation or storage vats. In a research paper published in 2014, Pascal Chatonnet et al. revealed that significant quantities of dibutyl phthalate (DBP) had been found in 59% of the (French) wines analysed [8]. Although, with the possible exception of biogenic amines that can have a ‘blood‐like’ odour and taste, the above compounds do not influence aroma or taste, their presence in wine other than at very low levels should be regarded as a fault; more of this will be discussed in Chapter 14.
Of course ethanol, the alcohol of all fermented drinks, is a known carcinogen and is classified as ‘a human carcinogen’ (Group 1) by the IARC [6]. It is toxic if consumed in excess, and there are reported cases of death due to alcohol poisoning and other issues related to single acts of excessive consumption. Long‐term regular consumption of ethanol, other than at low levels, is also a causal factor in several carcinomas, liver diseases, and other health problems such as obesity, as wine lovers and imbibers of other alcoholic beverages are regularly made aware. Acetaldehyde is considered a fault in wine only if present in excessive amounts, which generally means having a negative impact upon aroma, but when associated with alcohol consumption is also classified as ‘a human carcinogen’ (Group 1) by the IARC [6].
1.5 Sulfur Dioxide and Other Possible Allergens
Some individuals are allergic to grapes or alcohol. However, some compounds may be present in wine that may cause allergic reactions. The most important of these is sulfur dioxide (SO2), which is generally added at several stages of the winemaking process for its antimicrobial and antioxidant properties. Even if none is added by the winemaker, most wine contains SO2 as it is naturally formed by yeast during the alcoholic fermentation. Allergic reactions to this compound, which is also used as a preservative in a wide range of foods and drinks, are not uncommon, and individuals with asthma may suffer particularly adverse reactions. Many other people show an intolerance. The total SO2 content of wine is regulated in the European Union (EU) and all major markets and any wine marketed that exceeds this must be
