James Halliday, arguably Australia's most respected wine writer and critic, answers all things surrounding the Australian industry in the Wine Encyclopedia. From someone who has immersed himself in the industry for most of his life, this is a distillation of the knowledge he has accumulated over the past 40 or so years. His summary is gleaned from qualified winemakers, conferences, scientific papers and, most importantly of all, from the academic staff of the Australian Wine Research Institute.
Read an excerpt compilation of wine terms below from The Australian Wine Encyclopedia.
For the full and definitive guide to all things wine in Australia, The Australian Wine Encyclopedia by James Halliday, published by Hardie Grant Books, is available in stores nationally and you can find a list of stockists here. If you would prefer a digital copy of The Australian Wine Encyclopedia, you can purchase the ebook version here.
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Additives
Additives to wine are controlled by the Australia New Zealand Food Standards Code, and by regulations thereunder. The regulations list a series of substances which may be added, and any substance not on that list cannot be added, even if it is in no way harmful. One example of the latter is sorbitol. It is widely used in the fruit juice industry, and gives the wine a softer and (arguably) more pleasant taste and mouthfeel – but it is an illegal additive. Finally, there is the curious situation that as one travels north across the equator, acid becomes the work of the devil; as one crosses in the opposite direction, sugar becomes the work of the devil. Good winemakers anywhere should not hesitate to add either substance if they believe the quality of the wine will be improved by the addition.
On the other hand, they should not follow the herd, seeking to rely instead on achieving balance in the vineyard so that the addition of either becomes superfluous. For a full list of permitted additives see Standard 4.5.1 of the Australia New Zealand Foods Standards Code. Since 2007 it has been legal to add up to 7 per cent of water to either the must or the finished wine, chiefly where water is needed to dissolve additives such as fining agents including casein and bentonite. It is also recognised that small amounts of water may be incorporated with wine during bulk transfer by pump from one vessel to another. However, it is not legal to add water simply to reduce the alcohol level; Californian winemakers, by contrast, are able to add up to 10 per cent of water for amelioration of fermentation problems.
Botrytis
Botrytis is the enemy of dry table wines, white or red, but is the essential driver for the making of sweet table wines. Botrytis cinerea (called pourriture noble in France and Edelfäule in Germany) is a microscopic fungus or mould that attacks first the skin and then the pulp of grapes in certain very specific climatic conditions, causing the skin to perforate and the pulp to lose its water. The grape then softens and shrinks, with a corresponding concentration of its remaining components, notably sugar and acid. The grey-brown grapes look extremely unattractive, and the juice first pressed from them equally so, but juice settling and subsequent fermentation produce the great sweet wines of the world. In every case, however, it is essential that botrytis develops once the grapes have fully ripened; if it attacks too early, unwelcome moulds join the party. Lindemans Porphyrys from 1923, 1937, 1949 and 1956 (all tasted in the 1970s) were great wines, but the contribution of botrytis was not easy to determine. In 1958 McWilliam’s made a magnificent Pedro Sauterne from heavily botrytised Riverina grapes back-blended with Hunter Valley semillon. However, it has been the De Bortoli botrytised semillons which, since 1982, have been the greatest examples in the sauternes mould, winning many hundreds of gold medals, and a very large number of trophies, over the years. Botrytis rieslings of considerable quality have also been made, with Yalumba (courtesy of Heggies Vineyard) a major practitioner.
Cordon Cut
Cordon cut wines are made from grapes which have partially dessicated (becoming significantly sweeter) on the vine. This is achieved by cutting either the individual cane with bunches attached, or one of the main growing arms (cordons) with multiple canes attached. The part of the vine that is detached seeks to sustain itself by absorbing water from the bunches.
Chambourcin
Chambourcin is a red grape hybrid (not to be confused with a cross) which first appeared in France in 1963, briefly becoming popular in the cooler and wetter parts of Muscadet; it is now on the wane there. Like all hybrids, it is strongly resistant to the mildews. It has high yields and produces a remarkably intensely coloured wine. For the coastal regions of New South Wales, notably the Hastings River, propagating it makes sense; why wineries in ‘normal’ climates should plant it, and use it for vintage port, is beyond me. The Achilles heel of the variety is a marked lack of structure on the back palate and a very short finish.
Diam
Diam is a new form of closure which came into use in Australia in the early years of the 21st century. The process was developed by the French Atomic Energy Commission. Large pieces of cork are ground to the consistency of flour, and are then treated to supercritical CO2 held at very low temperatures and under extreme pressure – in this state, the CO2’s penetration has the solvent capacity of a liquid. When the pressure is released, the CO2, and hence the cork dust, returns to ambient conditions, and all the trichloranisole, and any other taint compound, has been captured by the CO2. The ‘flour’ is then compressed and bound with a natural glue, forming the shape of a conventional cork. It is available in two densities, the lighter density guaranteed against oxidation for five years, the heavier density for 10 years. The former can be used for wines which the maker wishes to evolve and develop more quickly, with a controlled amount of oxygen able to pass through the closure. The guarantees may well prove to be conservative; the only question that some winemakers have is the possible taint from the glue.
The winemakers of the Mornington Peninsula in particular (although they are far from alone) have enthusiastically adopted the closure, and report no problems. A striking feature of the Diam when removed from the bottle is the perfect circle of colour on the bottom face (when the wine is red) and no wine transfer or streaking up the side of the cork. This is doubtless due to the fact that Diam regains 97 per cent of its full shape and elasticity within 30 seconds of insertion. By 2020 Diam will be judged either an unqualified success, or to have inherited at least some of the problems of natural cork.
Extract
Extract is, in the strict sense of the term, the measurable amount of non-volatile solids in a given wine: these include sugar, acids, minerals, phenolics, glycerol, glycol and traces of other substances. Paradoxically, a wine high in extract does not have to be high in alcohol or body; thus, German rieslings which are low in alcohol and light-bodied can have high levels of extract.
Frontignac
Frontignac, sometimes with the words ‘white’, ‘red’ or ‘brown’ appended, is an alternative and widely used name for muscat à petits grains. The term is often applied to table wines made from the variety; fortified wines use the abbreviated nomenclature of muscat. It is a superior grape to muscat gordo blanco.
Fortified Wine
Fortified wine is made by the addition of grape-derived spirit to partly fermented juice (occasionally unfermented). The addition prevents further fermentation taking place, and leaves the wine with not less than 18% alc/vol. It represented approximately 85 per cent of total wine production in Australia up to 1960. Approximately, because detailed industry statistics segmenting wines into the various fortified types on the one side and table wines on the other were not kept. What is known is that between 1927 and 1940 Australia exported more wine to the UK than did France, and that virtually all of it was fortified wine, sent in barrel. As at 2008, fortified wine sales in Australia constituted 3.7 per cent of total market value. The fortified wine market is split in the same two fundamentally different categories as table wine: high-quality, limited production wines and commercial, larger volume wines, the latter still sold in flagons as well as bottles. High levels of consumption of these wines by Australia’s Indigenous peoples is an ongoing matter of concern to the industry.
A transitional agreement between Australia and the European Community on trade in wine came into force on 1 March 1994. It involved a two-stage process: first, an agreement to agree on phase-out dates for the use of various descriptive terms that were then in common use in Australia, but which conflicted with EU use, and second, having reached that point, to agree on a phase-out date. Despite the fact that, strictly speaking, an agreement to agree on something has no legal efficacy, the intention of the wine agreement has been fulfilled. The last areas to be agreed were the use of the terms ‘port’, ‘sherry’ and ‘tokay’. In December 2008 an agreement covering fortified wine nomenclature was signed by the relevant ministers, and a phaseout period of 12 months for sherry, port and other fortified wines was agreed; in the case of tokay, the phase-out period is 10 years. Agreement on these details led to finalisation of all aspects of the wine agreement, and to its signing by both parties on 14 February 2009 in Brussels. The categories of port have been specified in a code of practice which will allow the continued usage of the terms ‘tawny’, ‘vintage’ and ‘ruby’, though without the word ‘port’ appended.
However, the region can be specified. Tawny can be classified as Australian (or by region – Barossa Valley, Rutherglen, et cetera) classic, grand or rare in a similar fashion to muscat. The word ‘sherry’ will have to be discontinued by December 2009, and in January 2009 Australia announced that it had adopted (and registered) the name ‘apera’ to replace ‘sherry’. Once that generic description has been determined, the code of practice defines pale dry, medium dry, medium sweet, sweet and cream as more or less corresponding to the fino, amontillado, oloroso and cream terms used by Spain, and which are no longer available. The fortified muscat wines of northeast Victoria are unaffected by the agreement, as muscat is the name of the grape used. Tokay, however, is not (the grape is muscadelle) and Hungary objected to the continued use of the name, even though its sweet wines are not fortified (simply botrytised) and the spelling (tokaji) is different. The compromise of a 10- year phase-out was ultimately agreed, but, once again, Australia has moved pre-emptively, and has registered the name ‘topaque’, which will gradually replace ‘tokay’. In future, tawny, muscat and topaque will fall into four categories: Australian (simply the name tawny, muscat or topaque as the case may be), classic, grand and rare.
Gewurztraminer
Gewurztraminer (a white grape variety often shortened to traminer) might at first sight appear to be at a standstill in Australia, its annual crush having increased only marginally since 1987. This obscures the fact that plantings in unsuitably warm regions have been removed, and that the focus of activity is now centred on Tasmania, the Yarra Valley, Macedon Ranges, Adelaide Hills, Eden Valley and Upper Goulburn. That said, the Australian wines still do not deliver any of the spicy pungency of the grape’s home ground in Alsace, France. It may well be that Australia has poor clonal stock to choose from.
Heat Degree Days
Heat Degree Days, often abbreviated to HDD, was devised in 1944 by distinguished US oenologists Maynard Amerine and Albert Winkler. It traces its roots back to 1735, and then to the mid-19th century observation by de Candolle that there is little vegetative growth in the vine at temperatures below 10˚C. Amerine and Winkler assumed a seven-month growing season (in Australia October to April) and calculated the number of HDD by taking the difference between 10˚C and the mean temperature of the month, multiplying that difference by the number of days in the month, then adding together the resultant figures for each of the seven months. The system has been refined, adapted and criticised, but remains the most widely used and understood system available; Dr John Gladstones has produced the most convincing and detailed adaptation of the system in Viticulture and Environment (2002). The first methodical research in Australia was undertaken by Dr Richard Smart and Dr Peter Dry in 1988, preceding that of Gladstones. They added indices for mean January temperature (in other words, for the warmest month); mean annual range (January minus July temperatures), which indicates the degree of continentality; annual rainfall; rainfall of the seven-month growing season; aridity (the difference between the vine’s need for water and the water provided by rainfall and humidity); relative humidity; and sunshine hours per day. By way of example, the HDD range for Australia has a low of 1020 at Launceston in Northern Tasmania, and a high of 2340 in the Swan Valley of Western Australia.
Irrigation
Irrigation can be used for two entirely different purposes. The first is to increase the yield of vines, regardless of the impact on quality. The second is to increase quality, but not quantity, by providing water consistent with the vine’s needs at crucial stages of the growing season. In the former scenario, it can be supplied by flood or overhead sprinkler; in the latter, by precisely controlled drip irrigation, allied with moisture-measuring devices buried in the ground. In Australia, the Riverina, Riverland, Langhorne Creek and parts of Currency Creek have relied on seemingly limitless amounts of water to generate high yields, but the rapidly changing climatic scenario means that whatever water is available in the future will be applied sparsely and precisely. Whether the cost of obtaining water and applying it in this fashion will make grapegrowing in the Riverland and similar areas economic is problematic. In all but a handful of the premium regions of Australia, the need for and use of irrigation will become more acute if, indeed, rainfall decreases and becomes less regular.
Jammy
Jammy is a tasting term describing excessively ripe and heavy red-grape flavours, sweet and cloying.
Kyeema
Kyeema was the name of a commercial aircraft that crashed while travelling from Adelaide to Melbourne in 1938. Its passengers included the senior family members of three of Australia’s most important wine companies: Hugo Gramp of Gramp’s Orlando, Tom Hardy of Hardys and Sidney Hill Smith of Samuel Smith & Sons and Yalumba. Charles Hawker, a federal minister, was also killed when the plane flew into Mount Dandenong in the Yarra Valley, not far short of its planned destination.
Layering
Layering is a method of vine replacement that has an ancient history, but is possible only where phylloxera is absent. When a vine dies, a suitable cane from an adjoining vine is pruned only to its maximum length (determined by the spacing between vines along the vine row) and buried in the soil except for its tip, which appears out of the soil at the point where the new vine will eventually grow. The cane will slowly grow its own roots, and the umbilical cord between it and the mother vine can eventually be cut, although it is not uncommon to see it left as a permanent arrangement. If there is no suitable cane, or even where there is, an alternative is to plant a new rootling protected by a plastic cylinder known as a grow-guard, which keeps the young vine safe from attack by rabbits or wallabies, and also promotes a good rate of growth.
Minchinbury
Minchinbury was a once-famous brand of sparkling wine made by Penfolds, but it was also a significant part of the viticultural scene in the greater Sydney area between 1821 and 1977. When Captain William Minchin retired from the New South Wales army in 1819, he was granted 4000 ha of land near Rooty Hill. After his death in 1821 his daughter inherited the property, shortly afterwards selling it to a Dr McKay. He planted the first grapes at what was by then known as Minchinbury, and used convict labour to work the land and build the winery of dressed stone with walls that were 8 feet thick in places. The original cellars remained in use for the next 150 years. Towards the end of the 19th century James Angus bought the winery and vineyards, and extended both.
In the late 1890s he began making sparkling wine under the direction of Leo Buring; during this period phylloxera attacked the vineyard, necessitating its complete replanting with grafted vines. Nonetheless, Frank Penfold Hyland was sufficiently impressed with the Minchinbury wines to purchase the vineyards and cellars in 1912. For the next six years the property was managed by Leo Buring and, when he left, he was replaced by Ivan Combet, who remained as winemaker until his retirement at the end of the 1960s. In 1949 over 100 ha of vineyard were in production, but encroaching urban development made the land so valuable that pieces were progressively sold off; by 1973 a little under 14 ha remained, gewurztraminer accounting for half, along with riesling, trebbiano and some chasselas. It was the traminer and riesling which made the Penfolds famed Trameah, first sold in 1920. The author tasted bottles of the wine made in the 1960s and ’70s, and it is no surprise that this wine, along with occasional 100 per cent gewurztraminers (nine, incidentally, just as traminers), had significant show success. The land value was such that in 1977 the remaining hectares were sold.
Nebbiolo
Nebbiolo is accepted as the most noble of the many hundreds of Italian red grape varieties. Its nobility is consistent with its reluctance to perform well outside its kingdom in Piedmont, and also with the autocratic and unbending nature of its greatest wine, barolo. With many years of age, it is possible to see stylistic links with pinot noir, another reluctant traveller. But however fussy pinot noir may be, it does not approach the reluctance of nebbiolo to perform in Australia. Nebbiolo has been grown in the King Valley, McLaren Vale, Adelaide Hills, Mornington Peninsula, Heathcote, Mudgee and Murray Darling, and in none of these regions has it yet produced wines of unambiguous class. It may be that the combination of better clonal selection and greater vine age will produce worthwhile results in 10 or 20 years’ time, but it will take a brave and financially secure vigneron to prove the point.
Options Game
Options Game was invented by Len Evans in 1968. The rules were honed and fined by a group which met every Monday lunchtime at Len Evans’ restaurant, Bulletin Place, in Sydney. Three of the regular attendees (including the author) were lawyers, so, in its purest form, there was an exceedingly strict protocol. Each person brings a bottle of wine, which is decanted out of sight of the other tasters, into a bottle simply bearing a number or initials. Thus the bottles brought to the table give no clue as to the origin of the wine, but the person presenting the wine knows which is his/hers. Each person takes it in turn to ask five multiple-choice questions of the other players about his/her wine. In all except two instances (four major communes of Bordeaux, and the communes of Haut Medoc) only three choices may be offered. One of those choices has to be correct. When answers to a question have been offered by all players, the person whose wine it is, and who asked the question, will say which answer is correct. (Answers are given on a rotating basis: person B, then C, then D, then E for the first question, then person C, then D, then E, then B for the next, and so on.) Thus as the questions progress, players know more and more about the wine. A maximum of two questions can be asked about the vintage of the wine, but there is no restriction on the number of questions about variety, region or maker. A well-constructed series of five questions will leave the exact identity of the wine able to be determined by the last question.
Planting Density
Planting density of vines has varied enormously over the millennia in Europe; the difference in Australia is of lesser magnitude, but still substantial. It has often been observed that the configuration of vines has been determined by cultivation methods. Before the arrival of phylloxera in Europe, planting density was as high as 40,000 vines per hectare; the practice of layering was used without regard to vine rows simply because in many vineyards there were no rows, and weeding was done by hand. From this chaotic beginning came the idea of arranging the vines in rows, the spacing between the rows set at the width of a small horse-drawn plough. In Europe a typical spacing was 10,000 vines per hectare, with vines planted 1 metre apart along the rows, and a row width of 1 metre. The first tractors that appeared were similar to the insect-like, over-the-row tractors of today, with the wheels straddling the vines and thus running between adjacent rows.
Tractors in Australia, by contrast, were originally multipurpose vehicles, needing a row width of up to 3.7 metres, complemented by a spacing of 2.5 metres between the vines along the row, resulting in a planting density of 1080 vines per hectare. With the advent of cool-climate vineyards in particular, coupled with purpose-designed four-wheel-drive tractors, much narrower row spacing became possible, typically 2–2.2 metres between the rows, and 1.5–2 metres between vines, with a resulting density of over 2000 vines per hectare. Higher density plantings do exist, a few with the 1 metre by 1 metre classic configuration, with the aim (though not always the consequence) of naturally reducing the crop on each vine through inter-vine competition.
Petit Verdot
Petit verdot was a more prevalent red grape variety in Bordeaux before phylloxera than after, but slid even further in the 1960s and 1970s as earlier ripening merlot and cabernet franc replaced it. It is, indeed, the latest ripening of all the red Bordeaux varieties, and, like cabernet sauvignon, is deeply coloured – but it is even more tannic than cabernet sauvignon. With better clonal selection and better management of vineyard diseases, petit verdot has made a small comeback; Chateau Latour, for example, has been increasing the amount of petit verdot planted in its vineyards. Late ripening is not a problem for California and, while plantings there are not significant in area terms (not much more than 100 ha), the grape is spread thinly across Bordeaux (or Meritage) blends, consumers being fascinated by the idea of 2 or 3 per cent in a blend.
In Australia the variety has come from nowhere in a relatively short time. Mount Mary in the Yarra Valley has been growing it since its inception in 1971, as a small part of a Bordeaux-based blend (Mount Mary calls its wine Cabernets Quintet), but an increasing number of winemakers are releasing single variety petit verdots. Pirramimma has had outstanding success, and makes by far the best version; the Riverland and Murray Darling exponents are perhaps simply content with its ability to produce both colour and tannin irrespective of the yield. It is here that plantings have soared at breakneck speed since 1999, when the variety first merited separate mention in the official statistics. By 2008 plantings had risen to 1354 ha. There are signs that the increase in plantings may have peaked.
Queensland Coastal
Queensland Coastal is an unofficial name drawn in part from a Queensland Government strategy document released in December 2004 by the minister for wine (yes, there was such a person). It takes in the Gold Coast and Hinterland district, the Brisbane and Scenic Rim district, and the Sunshine Coast and Hinterland district, which between them then had no less than 40 wineries-cum-cellar doors, the most important by far being Sirromet.
Residual Sugar
Residual sugar (in winemaking circles often abbreviated to RS) is the measure of glucose and fructose which, either accidentally or deliberately, remains unconverted to alcohol during the course of fermentation. It is normally expressed as grams of sugar per litre of wine, and can vary between 1 gram per litre and over 500 grams per litre. White and red wines described as dry may contain 2 grams per litre, the sweetness completely obscured by the countervailing acidity and other extracted compounds or flavours in the wine. Indeed, it is rare to find a wine with less than 1 gram per litre of residual sugar, simply because yeasts cannot metabolise trace quantities of other sugars (such as pentoses); nor can these trace quantities be tasted – that is, these wines will appear to be totally dry.
Aromatic wines such as riesling grown in cool climates may contain as much as 25 grams per litre of sugar yet taste fruity but dry, particularly where the pH is below 3 and the acid in excess of 8 grams per litre. The juice from grapes picked at 13 baumé will contain 233 grams per litre of residual sugar, and, if fermented dry, will end up with an alcohol of 13.9% alc/vol. If, on the other hand, fermentation is arrested when the alcohol reaches 11% alc/vol, the juice will contain 50 grams per litre of sugar. If the fermentation is arrested so that the wine has 8% alc/vol, there may be up to 100 grams per litre of residual sugar. Even at this level, the sweetness may be interpreted more as juicy fruit flavours, and be most apparent on the mid-palate; the finish and aftertaste may be fresh and juicy rather than sweet. Once one gets into the upper end of Hungary’s tokaji essencias, the wine must have a minimum residual sugar of 250 grams per litre, but can attain twice this amount. The same is true of exceptional trockenbeerenauslese from Germany. At this level of sweetness the wine is stable, and may take years to ferment part of the sugar: Jancis Robinson, in The Oxford Companion to Wine (3rd edition, 2006, p. 567), records a German wine harvested at Nussdorf in the Pfalz in 1971 which was picked with about 870 grams per litre of sugar, and had reached only 4.5% alc/vol after fermenting for 20 years, producing a wine with about 480 grams per litre of residual sugar.
In Australia between 1955 and 1975, what were called spätlese rieslings were far from uncommon, and the best (particularly Leo Buring) were exceptionally fine wines at 30 years of age in the relatively rare instances where the corks had not given way (the sugar in sweet wines acts as a lubricant, allowing ready penetration of wine along the sides of the cork). The style then disappeared until the start of the 21st century, when winemakers in Tasmania, Pemberton and other cool regions began experimenting with earlier picking and leaving unfermented sugar. The first Tasmanian version was labelled FGR riesling, which might have stood for many things, but in fact meant ‘Forty Grams Residual’ (sugar). These wines are loosely based on the Mosel kabinett style. Again, in Australia a clear distinction has to be made between commercial or commodity wines with relatively low prices selling in volume through supermarkets in Australia and abroad. Here residual sugar of 4–10 grams per litre is routinely used in both white wines and red wines, as it has been demonstrated on countless occasions that consumers may talk dry, but drink sweet. Most people buying wine of this description are in fact unaware that part of the flavour comes from residual sugar. Quality barrel-fermented white wines (notably chardonnay) and all quality red wines are (or should be) dry.
Reverse Osmosis
Reverse osmosis has come into increasingly widespread use around the world (including Australia) since the mid-1990s. It relies on cross-flow filtration, a technique which sees the liquid (juice or wine) flowing parallel to the filter membrane under pressure, which causes water, some salts and alcohol to pass through the membrane filter. It is most often currently used for two very different purposes: alcohol reduction and must concentration, the latter ultimately leading to an increase in alcohol. Where it is used for alcohol reduction (its most common use in Australia), the colourless liquid which passes through the membrane is composed almost entirely of water and alcohol, the remaining wine passing back to the tank. The alcohol is then removed from the permeated liquid by distillation, and the water returned to the wine, so to produce a wine of reduced alcohol content. Because the water came from the grapes in the first instance, its return to the wine is not caught by laws preventing the addition of water. A sub-variant is low sugar juice (LSJ, removal of sugar from the must), where all the water removed is added back to, say, 50 per cent of the original juice. When used for must concentration, the water removed is simply discarded; this is a particularly useful practice in a wet, rainy year.
Somewhat controversially, the process has been more widely used even in good vintages to increase the alcohol and overall flavour of wines, as this appeals to the US market. In Australia the main use of reverse osmosis is on finished wines, where the selective removal of water and alcohol concentrates all other components. Interestingly, if one starts with a wine with, say, 15% alc/vol, as the alcohol is progressively reduced down to, say, 12.5% alc/vol, there may be three points, or sweet spots, along the way where the mouthfeel and flavour are in sensory balance. Thus rather than simply calibrate the equipment so that a 15% alc/vol wine ends up as a 13% alc/vol wine, a decision will be made along the way to terminate the process somewhere between 13% alc/vol and 15% alc/vol. Less common usages are to reduce volatile acidity, to remove Bretannomyces and (the winemakers hope) to reduce smoke taint (from bushfires).
Screwcaps
Screwcaps were invented in 1856 to seal glass jars, and in 1889 a screwcap was patented in the UK by one Dan Rylands. In 1926 they were introduced on whiskey bottles, and in the 1930s the University of California, Davis, conducted trials on bottled wine, including a 1936 colombard which was opened over 60 years later and found to be in very good condition. In the 1950s a number of companies developed versions of the screwcap, led by Le Bouchage Méchanique (LBM), which trademarked Stelcap. In 1959 systematic research began, in particular comparing the performance of Stelcaps with one-piece corks. In 1965, improved sealing wads demonstrated no difference between the performance of premium corks and Stelcaps; trials in Alsace in 1966 confirmed the results.
In 1968 official approval was given in France for use of the closure as a seal for wine, and the following year Chateau Haut Brion commenced commercial trials. In 1970 Australian Consolidated Industries (ACI) obtained the licence to manufacture Stelcap closures in Australia, and Yalumba trialled Stelcaps over previously inserted corks. In 1970 and 1971 screwcaps were evaluated in Switzerland with white wines made from chasselas, and in 1972 the first commercial bottling of wine with screwcaps was carried out in Switzerland. In 1973 a trial began in Australia under the direction of ACI and the Australian Wine Research Institute in conjunction with seven wine companies, and from 1975 to 1976 Saltram, McWilliam’s, Yalumba, Hungerford Hill and others released red and white wines with screwcaps. It was in the latter year that the results of three-way blind tastings conducted over the prior three years confirmed the success of the screwcap manufactured by ACI and called Stelvin. In that year Yalumba carried out the first commercial bottling of riesling under Stelvin, Montana in New Zealand following suit.
In 1979 Chateau Haut Brion abandoned the hitherto successful trial after the caps had failed due to defective liner materials. Notwithstanding the absence of any technical problems in Australia, Yalumba and the other companies ceased the use of screwcaps because of market resistance. At the same time the use of screwcaps in Switzerland was growing rapidly, reaching 10 million screwcaps per year in 1990 and exceeding 60 million by 1995. Californian producer Sutter Home had gone down the same track, and in 1995 sealed more than 10 million bottles with screwcaps. In 2000 Australian winemakers in the Clare Valley banded together to launch their rieslings under screwcap, quickly followed by New Zealand, and by 2003 worldwide shortages of screwcaps led to five-month production lead times. In 2004 the large Burgundian negociant business of Jean-Claude Boisset was presented with bottles of a 1966 Mercurey, a pinot noir from the Chalonnaise region of Burgundy, and reported, ‘It turned out that the wine had absolute freshness, great body and was in superb condition.’ This led to Boisset commercially releasing bottles of red burgundy up to grand cru level wine under screwcap. Boisset had, however, been pre-empted by the release of grand cru chablis under screwcap by Michel Laroche. Continuing trials by the AWRI through the first decade of the 21st century repeatedly confirmed the superiority of screwcap over all other closures in terms of freedom from taint, and, more importantly, freedom from random oxidation.
In 2004, 25 per cent of all Australian wines were bottled under screwcap. By 2009, 78.2 per cent of Australian wines were so closed; 12.1 per cent used one-piece (conventional) corks, 4.8 per cent used Diam, and the remainder was spread across the membrane-covered ProCork, Twin Top, the glass-button Vin-o-lok, the curious plastic Zork and various synthetic corks. It is asserted by some that screwcaps cause reduction, but the vast majority of researchers and scientists do not agree, postulating that wine bottled with the potential to show reduction will do so regardless of the closure, and will in fact do so, in particular, with cork closures. (Some synthetic materials are capable of absorbing thiols and other precursors.) This apart, the argument that screwcaps inhibit the proper ageing of red wine is rejected by most (but not all) researchers. They point out that the changes of age are anaerobic, and that the amount of oxygen in solution in the wine when it is bottled, and any oxygen introduced into the headspace between the bottom of the closure and the top of the wine, will be consumed within one month of bottling. Thereafter the changes will be anaerobic unless the cork fails to prevent the ingress of oxygen, which leads to random oxidation.
Topaque
Topaque is the name adopted by Australia in January 2009 to replace tokay; the reasons for the change appear in the apera entry. To complicate matters, there has been no necessity for any change in the use of the name muscat, nor the retention of the word ‘tawny’ (without the word ‘port’ appended); thus, for topaque, muscat and tawny, the three most important fortified wine categories, there will be four categories of ascending quality and age: Australian, classic, grand and rare.Touriga Nacional
Touriga nacional is the red grape cornerstone of Portuguese vintage port which, after centuries of use for this purpose alone, is now also being used in the production of high quality Portuguese table wines as a blend component. Deeply coloured, thick-skinned and tannic, a small percentage in a blend makes a major impact. In 2007 there were 53 ha of touriga in Australia, 28 ha being grown in South Australia (some used by Seppeltsfield). Since that time it has spread across Victoria (Bendigo, Goulburn Valley and Rutherglen), into New South Wales (Hunter Valley, Mudgee and Canberra District), and thence into Queensland. It is used both in table wines and in vintage fortified styles, and grown by 36 producers.
Ullage
Ullage refers to the space between the upper surface of wine in a barrel, cask or bottle, and the stopper or bung used to close the container. Also called the head-space, it may be present from the outset, or be wholly or partly formed as the result of evaporation of the wine, or seepage through the container or its stopper. In the context of wine bottles, where the term is most commonly encountered, it is the distance between the bottom of the cork and the level of the wine in the bottle when it stands upright. Unless the wine has been subjected to extreme heat, or there is a defect in the cork, ullage will develop slowly, starting approximately 1 centimetre below the cork and over a period of 20 to 30 years increasing to 3 centimetres or more below the cork.
Once the level falls to 4 centimetres or more, prudence would suggest that the wine should be professionally recorked, having first been tasted to ensure it is sound, and topped up to the original level with the same or a similar wine. Bottles with greater ullage are usually oxidised and not really suitable for drinking, unless the age is extreme and it is approached as a piece of living history. Occasionally, and for no apparent reason, a bottle with large ullage may turn out to be largely unaffected. The colour of the wine in the bottle before the cork is removed may provide some advance information: if the wine is bright in colour there is cause for hope. The whole subject will become of decreasing importance in future decades as screwcaps progressively replace cork.
Vine Pull Scheme
Vine Pull Scheme was legislated by the South Australian Government in 1987, compensating growers who removed old vines or unwanted varieties, and left their land unplanted. It came in the wake of five years of grape surpluses and very low prices. In 1982 the surplus of 9000– 10,000 tonnes of red grapes led to the uprooting of 400–500 ha of vines, and the continued top-grafting of grenache and mourvedre to chardonnay (a grafting program which had begun the previous year). In 1984 Penfolds vintage notes said it was likely that 500 ha of vines would be removed in the winter of 1984 from the Barossa Valley, Clare Valley and Angle Vale areas.
In 1985 shiraz brought $275 per tonne, grenache $190 per tonne, chardonnay $420 per tonne and riesling $385 per tonne. It was these sub-economic prices, and the distortion between white and red grape prices, that led to the introduction of the Vine Pull Scheme. It resulted in a reduction in the overall plantings in the Barossa of 9 per cent; the greatest loss was the destruction of old shiraz vines which, 10 years later, were bringing prices in excess of $3000 per tonne from Penfolds. By 1989 the price of shiraz had risen to $800 per tonne, cabernet sauvignon to $1220 per tonne and chardonnay to an astonishing $1590 per tonne (largely unwanted 20 years later), while riesling slipped backwards.
Volatile Acidity
Volatile acidity (commonly shortened to VA) is caused by the interaction of bacteria (known as Acetobacter) with the alcohol of the wine and oxygen to produce acetic acid. It is far more commonly encountered in dry red wines than dry white wines, and has a maximum legal level in Australia of 1.5 grams per litre, almost twice the taste threshold level (0.8 grams per litre). The twist in the tail is that acetic acid itself does not have the sharp (at high levels, vinegary) smell, but its accompanying ethyl acetate does. Ethyl acetate is usually produced concurrently with acetic acid and in the same relative proportion, and has no legal limit. Some Saccharomyces yeasts produce significant levels of acetic acid, but almost no ethyl acetate; thus, the wine may have a high level of volatility by analysis, but this is not apparent on the palate. Recent advances in reverse osmosis allow the reduction of acetic acid from wine without significant downsides.
Whole Bunch
Whole bunch is, in part, self-explanatory, but has different implications for white wines and red wines. Wineries in Champagne do not have crushers or crusher-destemmers. All three of its varieties – chardonnay, pinot noir and pinot meunier – are placed as whole bunches in the specially designed champagne presses. The purpose is to minimise extraction of tannins or other phenolics from the skins and pips of the grapes, although some minor extraction from stems is a necessary trade-off. The result is very clear juice with pristine varietal fruit flavour, albeit at the acidic end of the spectrum.
In Australia, and other parts of the New World, whole-bunch pressing of chardonnay, semillon and riesling has become common for the best wines made from those three varieties. With red varieties, the application is very different. Here it refers to the practice of fermenting whole bunches, either as part of each batch, or, less commonly, as the whole of each batch. Beaujolais (notably), Burgundy and the Rhône Valley are the chief practitioners in France; the technique is not used in Bordeaux. The rationale for the use of whole bunches turns on intra-cellular fermentation, which is not precipitated by yeast, but by enzymes in the berries. When a bunch is cut from the vine it remains alive, in the sense that it can, and does, initiate enzyme-triggered changes in its chemical composition. The first change is the consumption by the berry of its stored CO2, which it needs to stay alive. Enzymes then attack the sugar in the berry, turning it to alcohol and producing more life-sustaining CO2 in the process. If CO2 is readily available from the surrounding atmosphere, the berry may also absorb it from this source.
The fermentation which thus occurs within the individual cells bears no relationship to normal fermentation. Over a period of days, or up to two weeks at lower temperatures, up to 2 degrees of alcohol accumulate inside the berry, at which point the alcohol effectively kills the berry, and the intra-cellular fermentation ceases. During that fermentation period, however, glycerol, methanol, ethyl acetate and acetaldehyde will have been produced in significant quantities, along with a range of amino acids. It is these substances which give wines made using whole-bunch/ carbonic maceration their characteristic lifted bouquet.
Xanadu Wines
Xanadu Wines was founded in 1977, but overreached itself in 2005 against a background of wine surpluses, and the business was acquired by the Rathbone Group, completing the Yering Station (Yarra Valley), Mount Langi Ghiran (Grampians), Parker Coonawarra Estate and Xanadu (Margaret River) structure. It is a tribute to the business acumen of CEO Doug Rathbone that there is no overlap of wine style, and each winery has depth to its premium and ultra-premium offerings. Xanadu has 130 ha of vineyards, and a 65,000-case winery, exporting to all major markets.
Yeast
Yeast is a one-celled organism without which wine would not exist, nor food staples such as bread. It is ironic that the New World’s current fascination with natural or wild fermentation (the rule rather than the exception in the Old World) should come at a time when the scientific understanding of and research into yeasts is expanding exponentially. Pride of place must still go to Louis Pasteur, who demonstrated that this organism was the trigger for the conversion of grape juice to wine. Pasteur was the father of the science of microbiology, and it is fitting that yeast was the first eukarotic organism whose genome was sequenced in 1997. Yeast has become the model organism for studying human diseases such as cancer; yeast scientists Paul Nurse and Lee Hartwell received the Nobel Prize for Physiology in Medicine in 2001.
The yeast population has served humankind since the dawn of civilisation. The member of overwhelming importance to winemaking is Saccharomyces cerevisiae. It best meets all of the requirements for fermentation: ability to tolerate a low pH medium, significant amounts of sulphur dioxide, steadily rising levels of alcohol and relatively high fermentation temperatures. Unless stressed, it does not produce undesirable side effects, and its use extends (via lees) well after its death. There is a vast number of different strains or types of S. cerevisiae sold around the world under different commercial names: one of the best known is EC1118, or Prise de Mousse, sold by Lalvin. In the last 20 years 5538 genes have been identified in yeasts, and, in a significant number of instances, the effect of a given gene identified. Some genes are thoroughly undesirable if overexpressed; thus the ATFI gene results in a wine with an overpowering ethyl acetate (nail polish) aroma. Others are highly desirable.
The conversion of grape juice to wine is a complex, multistage process, resulting in a liquid that is 83–89 per cent water, 10–15 per cent alcohol, 0.4–1 per cent glycerol, and 0.5–1.5 per cent acid. Only a fraction of the remaining 1 per cent (or thereabouts) constitutes the volatile flavour compounds that give wine its aroma and flavour. It is here that the specific action of different strains of yeast becomes critical, particularly given that grape juice (of any given variety) has much less fruit aroma than the wine it makes. It is also necessary to distinguish between, first, grape flavour compounds which are present in both grapes and wines and are not altered and liberated by yeasts; second, grapederived flavour precursors which are altered by yeast; and, third, yeast-derived flavour compounds probably produced as general sidereactions of primary yeast metabolism. Esters are biosynthesised by the yeast, and confer a range of distinctive fruit aromas, including strawberry, apple, banana, peach, berry and pineapple. Quite why these esters should be produced is not understood, as they do not appear to have any metabolic function. But they most certainly explain why wine writers use such terms. The precursors for some esters, called higher alcohols, are themselves potent aroma compounds, ranging from fresh-cut grass to roses to nail polish.
Then there are the volatile acids, mainly acetic acid, also biosynthesised by yeasts. These acids are always present – at low levels beneficial to wine quality, at high levels destructive. Here choice and consequence become particularly stark. Some yeast strains release volatile thiols, whereas others do not. Jan H Swiegers, of the Australian Wine Research Institute, who has published a lengthy paper on yeast modulation of wine flavour with Professor Isak Pretorius (Advances in Applied Microbiology, volume 57), puts the thiol impact into perspective thus: ‘One milligram of a certain volatile thiol is enough to flavour almost a million litres of wine.’ Thiols originate from the grape as aroma-bound, non-volatile, amino acid–bound precursors. Through the process of fermentation, yeast enzymes split the volatile thiols away from the amino acid, releasing them into the wine. Here they create box-tree, passion fruit, guava, gooseberry and (at higher concentrations) sweaty aromas. Once again, wine writers can take comfort.
At present, the most effective thiolrelease yeast strain can unbind only about 5 per cent of the volatile thiols from their precursors. Writes Swiegers (in a separate, unpublished paper): ‘There is a huge, untapped aroma potential remaining in the grape (and ultimately in the wine that we drink!).’ Together, Pretorius and Swiegers become even more poetic when they conclude their yeast modulation paper: “The infinite number of flavour profiles of bottled wines results from the synergy between grapes and yeast … The blending of the precise amounts of different flavour compounds to produce the distinct flavours of different wines is akin to the blending of the sounds of many instruments [in an orchestra] … When in perfect balance, all the flavour compounds … result in a satisfactory sensory experience that the wine connoisseur will declare to be a symphony in a bottle.” Expressed thus, science becomes art. The artist, however, will have to be careful not to make the painting too colourful. If this technology comes to full flower, it will be most useful with cheap wines made from high yielding, warm-region vines. These often lack varietal character; enhancement of this would prima facie be beneficial. It is an altogether different question with, say, the great wines of Burgundy.
Given the present and future ability to dial up flavour numbers by the use of highly specific yeast strains, where does this leave wild yeast fermentations (however called), and where do they fit in the choice-and consequence scheme of things? Well, for a start, most of these yeasts are not found on grape skins, common belief to the contrary notwithstanding. Rather, they are airborne and are carried around vineyards and wineries by the wind and by such vectors as fruit flies. The yeasts responsible for initiating spontaneous fermentations usually belong to four genera different from S. cerevisiae: Hansenula, Klöckera, Pichia and Torulopsis. These four have a number of things in common: they are intolerant of sulphur dioxide, they are intolerant of alcohol and most will start to expire once the alcohol reaches 2–3% alc/vol. They will not populate in sufficient numbers prior to this time to prevent other yeasts (most notably S. cerevisiae) from growing.
On the other side, possible disadvantages are higher alcohol conversion from the same sugar level, and less acidity at the end of the ferment. But all ferments complete their course, and there is no greater sulphide production, nor ‘off-barrels’. Research carried out with the assistance of the AWRI since 2000 has confirmed that in the first week of ferment four to five different groups of non–S. cerevisiae yeasts were identified each day, with around 17 groups in total. After the S. cerevisiae yeasts took over, there was only one group of non–S. cerevisiae yeast which continued through to the end of fermentation. Yalumba has also studied the effect of using eight inoculated yeasts outside S. cerevisiae; this gave rise to different flavours, textures, and chemical analyses. In many cases, these fermentations were preferred to that of the S. cerevisiae control fermentation, but in no case were they better (in sensory terms) than the wild yeast control fermentation. It seems highly probable that over a period of time the winery-resident population of yeasts will stabilise, particularly where the pomace is returned to vineyards near to the winery. The idea that a more distant vineyard may bring a particular character attribute to a specific wild yeast (or yeasts) has little scientific support, but the possibility cannot be ignored.
Zinfandel
Zinfandel arrived in the US in the early 19th century. DNA profiling has shown that it is in fact the same as primitivo, a red grape grown with considerable success in southern Italy. In some ways it parallels Australian shiraz, for it responds to an extraordinarily wide range of climate and terroir. In the US this means from the Sierra Nevadas to Lodi in the Central Valley, thence to Russian River in the Sonoma Valley: in other words, from very warm to distinctly cool. As is the case with shiraz, the flavour and structure of the wine changes dramatically as you move from warm to cool, but all the manifestations have easily understood appeal.
From a viticultural viewpoint, it is unique. Any given apparently ripe bunch at harvest time will have some bright green, totally unripe berries spotted throughout, without rhyme or reason, and more than likely a similar number of raisined berries. Conventional methods of assessing ripeness are virtually useless; the most successful makers rely on a sixth sense they have developed through observing the vine and making the wine for many years. It might be seen as appropriate, therefore, that Sutter Home developed Blush, which is often labelled White Zinfandel (although it is, of course, made from black zinfandel). Blush is a slightly pink, more or less dry and largely tasteless wine which swept across the US like a tidal wave in the 1980s. Blush has no counterpart in Australia, nor is it ever likely to do so: it is one of the less appealing forms of wine to have been made in recent times.
Cape Mentelle pioneered plantings in Australia in the early years, doubtless due to David Hohnen’s time in California before founding Cape Mentelle in Margaret River. The wine produced has always been interesting, the quality varying from good to excellent. The only other growers to follow over the next decades were Wilson Vineyard in the Clare Valley and Kangarilla Road in McLaren Vale. (This is ignoring a tiny planting in what is now Domaine A in the Coal River district of Tasmania, which produced remarkable zinfandel.) It is now grown with success in the Hilltops region, and in the Adelaide Hills as well as the Margaret River, McLaren Vale and Clare Valley to generally good effect. Plantings in the Riverland, too, have been moderately rewarding. Nonetheless, it is still not grown in sufficient quantity to be recorded in the generally available statistics, which, given the apparent mania for obscure varieties, is mildly surprising.
