"Plant a vine ... become entangled in its tendrils.
We begin the second section of the book on cultivating wine grapes.
We are now leaving the realm of flavor and entering into an area of wine knowledge that even many winemakers lack understanding of - farming grapes for fine wine. While my academic background was in plant science in general, and agronomy in particular, it was after more than a decade of winemaking before I turned my attention to farming. Most enthusiasts and students of wine will have little or no practical experience with farming of any sort. In modern developed countries only a tiny percentage of the population farms. I have come to believe over my many decades of winemaking that understanding the vine is both the most important and most satisfying aspect of the work.
Section II: Winegrowing
“Plant a vineyard and you will become entangled in its tendrils.” – French proverb
INTRODUCTION
Cultivating vines for wine is called grape growing in California. The academic term for the study of this agricultural art is viticulture. I prefer the word winegrowing. Because, after all, wine grape varieties are not sold for consumption as fresh produce like table grapes. They are grown solely to be transformed into wine. In other words, a wine grape has but one purpose, which is to become wine. Furthermore, winegrowing is the central and essential activity that forms the foundation of quality in wine. No cellar skills or advanced technology can turn ordinary grapes into fine wine. Winemaking skills largely protect you from making bad wine. This is particularly true with red wine. In white wine making cellar technique plays a larger role. However, with either in order make fine wine, one must first grow fine grapes.
Therefore, in an ideal world, all vineyard decisions would be made based upon their subsequent [AK1] effects on the wine. The French term vigneron describes someone who both tends the vines and makes wine. (In English, the literal translation would be vine grower.) The French word assumes that anyone who grows wine grapes also perforce makes them into wine. This has long been the common practice in traditional European wine regions and remains the benchmark method. Controlling both the quality and style of a wine is most reliably accomplished when one person guides the process from soil to bottle. While this is not the sole path to high quality, it is the surest.
Winegrowing is intimately linked to winemaking. More than a perfect pairing, neither enterprise can exist without the other. That said, each is a distinct craft with its own particular demands. Both are complex and difficult endeavors, requiring lengthy practical apprenticeships. It is rare for a practitioner to be equally adept at both. Nonetheless, all winemakers must acquire detailed hands-on knowledge of winegrowing. Without it, their cellar skills are hobbled. Knowledge of vineyards greatly enhances the winemaker’s ability to produce the best wines. This is especially true of red wine. The best method for acquiring this knowledge is hands on practice supported by viticultural studies. As early as possible in their career, winemakers should perform all the actual hands-on work of tending vines through the growing season. This is the only way to obtain granular knowledge of the tasks involved[1]. Tending even a few vine rows will provide a sufficient education if carried out over the course of several seasons. Winemakers will frequently be involved in vineyard decisions that affect flavor. Practical experience with vines equips them to do this correctly.
The best education results when the winemaker is given the opportunity to plant, train, and tend a vineyard from bare earth. Only in this way can they consider every decision and how each will impact the resulting grapes and wine. Time spent with the vines is always time well spent for a winemaker. To make good wine you must learn the language of the vines. They will never learn your language, so you must learn theirs. And vines speak slowly. Their time is not our time. To become fluent in their language you must invest years of study. A vineyard cannot be learned in a single season. So too you must learn the language of the viticulturist. Without this you will not be able to communicate what you wish done with the vines. You must understand what is possible so as not to make unreasonable or impossible requests from the grower. A vineyard manager tasked with ill-informed demands will quickly lose respect for the winemaker making them.
No matter how diligently you study the vine, yours will be a life-long apprenticeship. Unlike winemaking, whose basics can be mastered relatively quickly[2], winegrowing will always remain a work in progress. Each vintage is unique in the seasonal pattern of its weather, and you have never experienced it before, nor will you get to again. To be competent in the cellar a decade will suffice, but a lifetime is too short to fully comprehend the mysteries of the vineyard. Winemaking has been called a lifelong lesson in humility. Winegrowing is even more so. In winegrowing you grapple with the full spectrum of nature and nurture. The vine is a living system in relationship both to the fixed specific soil and to the ever-changing seasonal weather patterns of the vintages. The more you learn; the more you will question. In some ways winegrowing is not a search for the best answers, but rather a search for better questions.
It is beyond the scope of this book—or any single book—to address every aspect of winegrowing. I will focus on those that the winemaker is likeliest to influence. In an estate situation where the winery owns the vineyard, the winemaker can exert influence at nearly every stage of the growing year. In the case of purchased grapes, the winemaker’s input is more circumscribed, but that does not mean you are powerless. A vineyard that deprives the winemaker of a role in the winegrowing is a vineyard that will never make the highest level of wine quality.
Chapter 8
Overall Approaches to Winegrowing: conventional, organic, sustainable, regenerative
Agriculture was the first cultural art from the perspective of communal culture. Certainly painting, music, and oral poetry existed before agriculture, but only within limited tribal groups. The collective cultural strength of large accumulations of people began after farming developed. Over the 10,000 or so years since, many techniques and tools have developed. The thoughtful practitioner should avail themselves of all, while, like the physician, should always first think to “do no harm”. In the case of medicine, it is to the body; in farming, it is to the land. Keeping the land free from harm is paramount.
It is somewhat of a simplification, but farming philosophies can be roughly divided into four large schools – conventional, organic, sustainable, and regenerative. This is not to say that one must stay strictly within one or the other while practicing the art. You can take the best from each if you choose to do so. All contain some useful tools for the task.
Conventional or modern farming dates back to the advent of mechanization during the industrial revolution. The advances in understandings of plant biology and chemistry of the 20th century accelerated its developments. Lowering the cost of farming has long been a major goal of modern conventional agriculture. It succeeded via many avenues, though science and technology were the engines. Two of the most significant are mechanization and the efficiencies of large scale. The use of synthetic fertilizers and pesticides also played a role. So too did the breeding of better plant material, and in recent times the utilization of gene splicing towards the same end. While this system of agriculture has alleviated hunger worldwide for literally billions of people, there is little place for a strictly conventional agricultural approach when growing fine wine. Large swaths of famous French appellations adopted conventional agriculture from the 1950s through the ’70s. It proved to be a disastrous experiment that harmed the soil, the very basis of wine flavor, and it has largely been abandoned as a result.
Organic agriculture is a system that avoids or largely excludes the use of synthetically compounded fertilizers, pesticides, and growth regulators. It relies on composted animal and plant wastes for fertilizers to the greatest extent possible. Pests are combatted by cultural methods[3] and biological agents, including purely elemental pesticides such as copper and sulfur. are allowed. The concept of the soil as a living system is central to organic growing. Recently, winegrowers have adopted many of the core practices of organic agriculture, without necessarily embracing every proscription. Organic methods are well on their way to becoming standard thinking and practice[4]. Nonetheless, it is generally more difficult to farm in a strictly organic fashion. It is both slower and more labor intensive, and hence more expensive. In many winegrowing regions, grapes can only be called organic if the vineyard has been certified compliant by third party inspection. Local control has created a hodgepodge of rules; some are more stringent than others. Not all are based on scientifically valid premises.
Sustainable agriculture relies on a holistic approach that considers each individual farm as the basic unit. Sustainable agricultural systems take a multi-path approach to quality production. They utilize natural resources and regulating mechanisms to reduce pollution, and to ensure minimal negative impacts on the environment. Preserving and, ideally, improving, the soil is primary. They encourage biological diversity and reduced use of non-renewables and off farm inputs. Economic sustainability and social justice are also part of this philosophy of farming. It is the only system that addresses these social issues directly. Family farming is promoted as well as the welfare of the general community. Peer reviewed scientific information provides the foundation that supports sustainable agriculture. The input of practitioners, regulators, and researchers support the core of its tenets. Creating a system of best practices is the goal, rather than conforming to a belief system based on faith[5]. Sustainable agriculture originally developed as a self-assessment system, but in certain regions third party certification is an option as well.
Regenerative agriculture is the newest approach and is focused on not only preserving the health of the environment and soil, but also on building up and improving the land you are farming. Its primary goal is increasing the organic content of the soil which results in increased soil microbial diversity, better water holding capacity, a richer source of nutrients for the plants, and the capture of CO2 from the atmosphere into the soil. Its primary tenet is to eschew disturbing the soil surface by plowing or other means and to plant diverse cover crops to encourage insect and microbial diversity. The use of foraging animals such as sheep to convert the cover crops to manure and lightly disturb the soil surface is also part of this system. Synthetic fertilizers are not used due to their known proclivity to damage soil. This system over time appears to improve soil fertility and may lead to more flavorful wine as a result.
Environmental stewardship
When comparing farming methods, the thoughtful practitioner must acknowledge that all farming depends on the health of the environment. An enlightened farmer is a de facto protector of the soil, the water, and the atmosphere. A farmer who doesn’t consider him or herself an environmentalist is suffering from profound intellectual myopia. This is especially true in farming for fine wine, which reflects the flavors of the soil and expresses the nuances of climate driven weather patterns. Patterns of temperature and rainfall are particularly important for the preservation of historical and culturally important winegrowing regions. Global climate change will have negative effects on winegrowing regions in the coming decades. Famous continental climates such as Burgundy, Champagne, and the Rhine are in grave peril.
Vineyard location and development: planting choices
The opportunity to select a site and develop a vineyard is one of the great pleasures and challenges of winegrowing. Site selection does not occur in a void. Most sites will be selected in regions already under wine cultivation, where specific local knowledge has accumulated. The single best book on the interactions of the vine with its site remains John Gladstones’s Viticulture and Environment[6]. A significant proportion of his book is devoted to conditions in Australia and New Zealand. However, the general discussions in the first 50 pages or so of this book are exceptionally good. It was an eye opener when I first read it many years ago, and it remains a valued resource to this day[7]. Much of what follows here has been informed by this important text. Three broad areas must be considered when choosing a site: climate, soil, and topography. All interact, especially soil and topography, but each will be dealt with individually.
Climate
Temperature is one of the primary regulators of the vine. Because it has profound influences on the type and quality of wine that can be made, climate in all its aspects must be considered thoughtfully. Man-made climate change must be taken into account as well. A well-cared for vineyard has an expected life of 30 years or more. All indications are that the earth will be significantly warmer 30 years hence than it is now. Growers should consider whether the vine varieties and rootstock that are appropriate for their region now will still be best for what all climatologists predict to be a warmer future. Vines currently grown at the warm limit of viticulture now may not be possible 20 years hence. Sites at or near the cool limit will become viable for a wider range of wine types. Growers interested in making wines from cool climates may need to relocate closer to the poles or to higher elevations. Water availability is another consideration, as vines demand more water in warmer conditions. The changing climate will also affect patterns of rainfall. Areas that currently receive adequate moisture without irrigation may not in the future.
At this juncture, it’s worth clarifying a few frequently misapplied terms. Any uncertainty regarding what they mean will confuse the discussion to come.
The first is macroclimate, which is the regional climate. Think of it as the climate of the appellation. The differences between the climates of Los Carneros, and the Edna Valley, two coastal appellations in California, are those of two macroclimates. Mesoclimates are climates found within a macroclimate, so one level of detail finer than a macroclimate. The vineyard is the mesoclimatic level of detail. If, for example, we are comparing two locations within Los Carneros, we are comparing mesoclimates. A large vineyard may have individual mesoclimates within it. Microclimates are the finest level of detail. When we speak of microclimates, we are discussing the climate within the individual vines or vine rows, which is to say conditions created by the vineyard itself. For instance, trellis choice, row direction, and vine spacing all affect the microclimate of the vines. So too will other vineyard cultural decisions such as leafing or shoot removal. These can produce both short- and long-term effects on the vines’ microclimate. The most common mistake made when deploying these terms is to refer to a mesoclimate as a microclimate—as in the all too commonly heard phrase “The microclimate of my vineyard....” Substitute mesoclimate, and the phrase is more accurate.
Wines are grown within two broad geographic categories continental and maritime. Continental climates refer to landlocked regions not influenced by the ocean or another large body of water. In these, we find a high degree of seasonal or vintage variation. Maritime[8] is the other large category, and maritime climates are influenced by the proximity of water. Coastal is another common designation for maritime climates. The moderating effects of a maritime climate tend to diminish vintage variation compared to continental climates.
Latitudinal limits are also a factor in winegrowing. The polar limits are defined by the cold hardiness of the vines. Winegrowing is not possible if the coldest month of the year averages below -1ºC or if a freeze colder than -20ºC occurs more than once every 20 years. The tropical limits of viticulture are restricted by both the vine’s inability to achieve dormancy, and the disease pressure resulting from the humidity. In tropical climes, elevation can moderate some these effects but not eliminate them.
The main climatic drivers of the vines are temperature, light, supply of moisture, and wind. These do not act in isolation from each other, but rather all interact to a greater or lesser extent. As but a single example wind will affect both the influences of heat and moisture.
Temperature
This is the most important climatic variable in winegrowing[9]. Over the years viticulturists have developed many systems for categorizing temperature’s effects on the vine throughout the growing season. Four systems are currently in general use, none of them perfect. My preference is the system that focuses on the mean temperature during the final month of ripening[10]. With its emphasis on ripening, this system skews towards the winemaker’s point of view. Regions where the month before harvest is colder than a mean of 15ºC are not capable of ripening wine grapes. Appellations with a 15–21ºC temperature range are ideal for producing the more delicate styles of wine. The lower end of this range is only appropriate for the most delicate white wines. A temperature range of 20–22ºC is optimum for the broadest spectrum of styles. In this range pigment and flavor production by the grapevine is optimum[11]. Areas that reach 23–24ºC are best utilized for dessert wine, and climates above 24ºC are in general unsuited to winegrowing.
Temperature of course affects the vine throughout the growing season—not only during the final month of ripening. Cool temperatures during flowering and fruit set will lower the berry’s seed count. These lower seed counts in turn lead to smaller berries and earlier veraison, and both are desirable. Temperatures in the late spring and early summer must be high enough to create fruitful buds for the following year’s crop. Even a relatively short warm spell is sufficient to accomplish this.
Soil temperature strongly affects the vine’s metabolism and growth. Winegrowers in Europe have long believed that well drained stony soils and slopes facing the sun bestow an advantage. Well-drained soils are warmer in the spring because a drier soil warms more readily. Stones retain and slowly release warmth into the soil, especially at night—extending the duration of the vine’s metabolic activities. Under these conditions, all stages in the yearly life cycle of the vine occur earlier. Earliness within the annual cycle is invariably beneficial, despite the persistent myth that slow ripening, or so-called hang time, is desirable for wine quality. In general, anything that can be done to hasten ripening makes for better wine. If the period between fruit set to veraison can be shortened, wine quality is improved. Many specific examples and explanations of why this is true will be presented throughout this section.
Some interested parties aver that continentality is critical to producing wines of the highest quality[12]. The seasonal weather cycles of the continental climate create growth and ripening patterns distinctly different than the maritime. Persisting cold temperatures and rain in the late winter and spring delay budbreak on continental vineyards. Bloom and fruit set then occur later and more evenly under generally warmer conditions. The period from fruit set to ripeness is constrained by this to 90–100 days. In continental climates grapes ripen under conditions of falling temperatures and sunlight with rain always a distinct possibility.
In contrast, maritime climates tend to be quite mild in the late winter and spring, often resulting in early bud break. Bloom and fruit set occur earlier in the year. Spring and summer conditions here can create vine management issues associated with mild weather, including inconsistent shoot growth and regrowth or difficulties stopping growth. Consequently, warm well-drained soil is even more important in maritime climates as a result, offsetting some of the negative impacts of warm spring rains. In general, the period from fruit set to ripeness is not limited by shortening autumnal day length and can stretch to more than 120 days. In maritime climates, temperatures drop more slowly in the fall, and both September and October can be quite warm.
There may very well be a theoretical advantage to continental climates based on the belief that wines that struggle to achieve basic ripeness have more complexity and finesse. However, this benefit is often offset by the greater seasonal variation in these climates, which means there is less likelihood of achieving basic ripeness or quantity of fruit in any given vintage. Continental climates are also much more at risk of increases in average temperature caused by climate change. All things considered; the potential vintage quality will be higher on average in maritime climates. This will likely be even truer in the warmer future.
Temperature fluctuations are exhibited across varied time scales. Seasons that are colder than average will cause problems in cold macroclimates, while being welcomed in warmer climes. The opposite is true of warmer than average seasons. Daily variability in temperature is important. It is not low average temperatures in the spring that create problems with frost damage; rather, it is too great a variability in day-to-day temperatures once shoots have emerged. The same is true of heat damage. Sudden heat spikes do much more damage to quality than a warmer average season. Either way, a climate that is closer to the ideal average temperature for any time of year is desirable, offering more leeway for daily fluctuations without negative effects. There will be fewer too cold or too warm days if the overall is moderate. Vineyard sites with great variation of temperature day to night will not produce the best wines. Color and flavor production are inhibited when mean night temperatures are 10ºC colder than mean day temperature. It is well known that in any given mesoclimate, topography and soil conditions that raise night temperatures are associated with higher quality wines. The most likely explanation is that more constant intermediate temperature allows the biochemical processes to continue in the vine during the night.
Light
Light and temperature are related. You need only step from the shade into the sunlight to understand this basic relationship. Vines require generous amounts of sunlight through several periods of the growing season. Wine grapes emerged evolutionarily in the Mediterranean basin, and the high amounts of sunshine found throughout the region remain congenial to them. While wine grapes are not limited to the Mediterranean climate, they are most at home there. Within the climate of origin, the vines require the least amount of trouble and toil to produce good wine. Excessively cloudy conditions and the associated humidity pose disease risk in addition to lowering the level of sunlight. Sunlight at flowering leads to better fruit set. It is also important for the formation of the next season’s fruiting buds, which occurs in early summer. If these fruiting buds do not form, then the following year’s crop will be reduced. Sunlight in the early spring advances the onset of flowering, which in turn leads to an earlier harvest—an always desirable outcome. Abundant sunlight just before and during veraison is necessary at this critical juncture when the vine’s energies turn towards ripening the fruit. Sunlight is almost always a benefit to the vine. Exceptionally, sunlight will damage the grapes if high temperatures and low humidity combine during the final month of ripening.
Both direct and reflected light have substantial effects on fruit maturation and composition. Red varieties in general respond positively to increased light regimes in the fruit zone. Many scientific studies and practical experience show that the greater the exposure of red fruit to light, the higher the quality of the resulting wine. As with any generality, there are caveats. Under conditions of high heat, direct sunlight will damage clusters. Both sunburn and raisining may result. Injury is more severe in low humidity situations. Some varieties, such as Merlot and Nebbiolo, are particularly prone to heat damage. Heat damage can be minimized by exercising caution when removing leaves in the fruit zone. In most regions, it is the side of the vine that faces the morning sunlight that is exposed by leaf removal. The leaves that shade the fruit zone during mid-day heat are best left in place.
White grapes on the other hand are not universally improved by increased light regimes and may be harmed by direct sunlight. The increased pigmentation in the grape skins caused by direct exposure to sunlight creates flavor effects that may well be negative in white wine[13]. It is not only the potential for increased yellow or brown pigments created in the fruit by light that is negative. Besides the undesirable colors, many of the compounds formed are flavored as well. These flavors are associated with more rapid aging of the wine in the bottle. Because of this an informed winegrower minimizes direct sunlight on most white fruit. Leafing should be carried out to allow sufficient air circulation to combat fungal disease without exposing the fruit unnecessarily[14]. If fungal disease pressures are high, it is better to leaf more thoroughly to protect the grapes and accept the subsequent excess sunlight effects. It is extremely difficult to make first-rate red wine from rotted grapes; conversely, many techniques are available to remove excess color from white juice and white wine, resulting in higher quality.
Rainfall and water supply
Grapevines thrive in areas with some summer rain. They also adapt well to Mediterranean climates so long as there is adequate spring rainfall, and soils deep enough to store this rainfall through the dry summer and into the fall. The vine must have access to water until ripening completes in the fall. Irrigation water, when available, gives a measure of control that is critically useful to offset the vagaries of weather. Irrigation is essential in sites with shallow soil and limited summer rainfall. An adequate supply of soil moisture is vital to the vine at flowering and set. However, heavy or prolonged rainfall will interfere with both. The lower temperature associated with rainfall is also a detriment to successful flowering and set. The vigorous, or rank, growth associated with overabundant moisture during flowering can itself lead to poor fruit set. After fruit set, a lack of moisture or even a mild drought stress is well tolerated by the vine and can continue through the summer-long interval between set and pre-veraison. In most years in the northern hemisphere, this stretches from mid-June to mid-August. Mild water stress during this period will limit berry size and advance the date of harvest. The potential for red wine quality particularly benefits from these low moisture conditions. Mild stress is actually desirable, whereas severe stress always interferes with quality.
The final phases of ripening, beginning with veraison, have different moisture requirements than the preceding summer phases. From pre-veraison through to harvest, it is best that the vines have access to sufficient water. The vine must be functioning optimally to produce the sugars and flavors necessary for wine. Soil moisture must be readily available during this time. Moisture stress in the final seven to eight weeks of ripening will lower wine quality. As just one specific example, the leaves of water stressed vines will export potassium to the berries. The resulting higher pH in the wine will hinder its quality. Excess water during ripening is also problematic, frequently causing the vine to begin regrowing laterals and shoots. This partitioning of the vine’s energy to vegetative growth as opposed to fruit ripening is undesirable. Heavy rainfalls during ripening can lead to berry splitting and increased fungal disease pressure. The risk from this type of damage is relatively greater in normally dry climates in the event of unexpected rainfall.
Relative Humidity
Vines have adaptations to protect themselves from overly arid conditions. Their evolutionary development in semi-arid regions equipped them for this. Vines respond to low humidity by closing their stomata, which blocks respiration, holds moisture within the leaves, and slows their metabolism. The more arid the conditions, the more water the vine must consume to thrive. With this greater quantity of water comes a greater quantity of potassium, which accumulates in the vine. In general, hot dry climates and conditions lead to high pH wines, which is undesirable. Climates with moderate relative humidity are best for the grape vine[15]. As with almost all environmental conditions, and for the grape vine itself, moderation is the operative qualifier. High humidity poses problems of its own, increased fungal disease pressure being the most dangerous. Highly humid environments are also often associated with excessive cloudiness—a further negative.
Wind
Wind, like other conditions, give rise to both positives and negatives. The on-shore sea breezes of maritime climates are welcome for their slight humidity and cooling temperatures—especially beneficial in offsetting afternoon heat. Mild breezes also help to prevent excess humidity from building up within the microclimate of the vine. Strong winds, on the other hand, can break tender young shoots in the spring and can interfere with flowering and set. High winds have an effect like low humidity, and in conditions above 10–12 mph the vines will shut down to protect themselves from moisture loss. Hot arid winds can be particularly harmful to the vine[16]. Prevailing winds tend to be westerly, which is one of the reasons that protected eastern-facing slopes are more desirable for vineyard locations.
Summary of ideal climatic conditions
As with anything, the ideal is frequently sought but rarely encountered. It would be improbable to discover any one location where all climatic conditions are ideal. Climatic conditions during the spring and fall are far more important for winegrowing than conditions during the summer and winter. In sum, the most auspicious spots will have ample sunlight and adequate but not excessive rainfall. The relative humidity will be moderate, and temperature variation should be minimal around a desirable mean, especially in the final six to eight weeks prior to harvest.
When we consider ideals of climate, man-made climate changes must be top of mind. All experts agree that the next 20–30 years will be significantly warmer than the current climate. Projected climate changes are becoming increasingly accurate at a local scale. These more granular predictions allow winegrowers to respond more precisely than making decisions based on known general trends. Any planting of new land or replanting of existing vineyards should be informed by the latest information and technology available. Consulting the most recent and specific models of climate change must be central to the general planning of any vineyard.
[1] Wittgenstein observed that the deepest understanding comes from showing not saying, and that it is by practice that we learn a craft. Theory can be beautiful, but it does not further the enterprise.
[2] While seven to ten years is normally enough to gain a working knowledge of winemaking, I do not mean to imply that one stops learning after that. Progress continues slowly throughout a winemaker’s life. And, barring accident or illness, our palates and tasting abilities improve with age, as was discussed in the chapters on tasting in Section I.
[3] A cultural method is any method that manipulates the plant itself to achieve a desired end. A good example of this would be leaf removal in the fruiting zone for better air circulation and lower disease pressure.
[4] Organic methods also echo some of the most traditional approaches. During the 1980s, when organic winegrowing was first being widely discussed, I recall Buck Bartolucci saying, “I’m basically organic because I learned to farm cheaply and minimally from my dad.”
[5] While I believe that all religions are good for their believers, I am a strict empiricist when it comes to winegrowing. Because of this, a quasi-religious system such as biodynamics has no validity for me. Certainly, pray for rain, or bury a cow horn by the light of the moon if it makes you feel better, but don’t expect it to change the weather.
[6] John Gladstone’s Viticulture and Environment was originally published by Winetitles, Australia 1992.
[7] However, Gladstone’s thoughts on climate change have not aged well and in fact have proven to be wrong.
[8] While maritime commonly refers to an ocean or sea, smaller landlocked bodies of water, such as lakes, bays, and large rivers, can also have this influence.
[9] In 1825 James Busby writing in Australia noted, “In Burgundy, where the sun’s rays do not act so powerfully in the production of saccharine matters, the wines are distinguished by richness and a delicacy of taste and flavor, while those produced under the burning sun of Languedoc and Provence possessing no virtue but spiritosity are generally employed in distillation.” A. Pirie, another antipodal wine writer working more than 150 years later, attributed the known coarseness of wines grown in hot dry climates to the moisture stress more than the heat of the sun per se. Heat and moisture stress are of course related in dry summer climates.
[10] These ideal temperature ranges assume that the supply of sunlight is not a limiter.
[11] Curiously, 20–22ºC is also the temperature range in both wine and beer fermentations where ester formation is optimal. It is the optimal ripening range for many fruits in addition to wine grapes.
[12] Unsurprisingly championed most of all by those who own continental vineyards.
[13] Many of the sun-formed compounds can taste attractive in the wine’s youth. But they are deceptive in a way, as with age in the bottle they invariably become less pleasant. This is another example of why wines must be judged over time to perfect technique. It is tempting for the winemaker to make decisions based on how the wines taste while in tank or barrel. But this temptation must be resisted. Decisions are best made based on how the wines will taste when they are being imbibed. Nota bene: You can’t make decisions retroactively.
[14] The notable exception to this rule is Sauvignon Blanc. This variety needs the direct sunlight to diminish high levels of pyrazines.
[15] The coastal valleys of California are cooler than the inland portions and produce finer wines. There has been a tendency to attribute this primarily to the temperature. While temperature is certainly a factor, the higher humidities associated with coastal fogs exert as strong an influence as the lower temperatures.
[16] On the California coast, it is not unusual to have strong offshore conditions during harvest. These “heat storms” bring dry desert air and high temperatures to the coast, causing severe stress and damage to the quality of the vintage.
[AK1]subsequent?
Very illuminating. The vine is at the heart of wine. We need to understand it to know how to make the most of the gift of fruit it gives us. Looking forward to the next edition.