Throughout history, wine was, and continues to be, one of the most important, influential, and popular alcoholic beverages in the world. In 2005, the consumption of wine accounted for 8.6% of the total alcoholic beverage consumption throughout the world, preceded only by spirits and beer [1
] Wine is made from fermented grapes or other fermented fruits. Grapes can ferment without the addition of acids, sugars, enzymes, water, or other nutrients because of their natural chemistry, as well as natural yeast inoculation [2
]. Under the action of yeast, the sugars in the grapes are converted into alcohols (primarily ethanol) and carbon dioxide, thereby making wine. In addition to its role as a popular beverage due to its distinctive flavor and aroma, wine can also act as a psychoactive drug, as wines are alcoholic beverages and thus can have intoxicating effects.
The history of wine is intimately connected to the history of humanity. The earliest traces discovered so far occurred in 6000 before Christ (BC) in Georgia and 5000 BC in Iran [3
]. The first recovered crushed grapes were dated to 4500 BC and were discovered in Macedonia [5
]. The first winery was dated to 4100 BC, and was discovered in Armenia [6
]. Wine was an occurring theme throughout the Bible.
Overall, wine making begins with proper selection and cultivation of appropriate grapes and ends with bottling of the finished wine. In terms of final products, wine making can be divided into still wine production, which produces wine without carbonation, and sparkling wine production, which produces wine with carbonation (the most famous of which is champagne, which only originates from the Champagne region in France). Still wine production can be further subdivided into red wine, white wine, rose wine, sweet wine, and other specialty wines [7
]. To produce the various wine products, similar yet unique processes are typically used. For example, for red-wine production, red grapes are harvested, de-stemmed, and crushed; all berry parts including skins, pulps, and seeds are fermented. Sometimes there may be double fermentation for red wine: first to convert sugar into alcohol using yeast, and then to convert malic acid into lactic acid (known as malolactic fermentation). Secondary fermentation accomplishes several key aspects, including adding flavors, reducing acidity, and ensuring stability in the bottle [7
According to [8
], red wine making is an extractive process involving the skins and seeds. They found that because of high levels of antioxidants (e.g., tannins and anthocyanins) that were extracted during the production process, red wine was less susceptible to oxidation. Secondary fermentation in red and even some white wines is also beneficial for stability against spoilage and in-bottle fermentation, because malic acid was consumed by conversion to lactic acid via Lactobacillus oeni
White wine, on the other hand, is only fermented by yeast and then chilled and stabilized (thus, the wine-making process is considerably simpler than that for red wine). Only the juice or “must”, which is pressed from the pulps of white grapes, is fermented. Thorough filtration must be used in order to remove all contaminants and microorganisms and, thus, prevent malic acid fermentation after bottling. The whole process is quite quick and, therefore, can produce wines with dry, crisp, and aromatic palates vis-à-vis red-wine profiles. Compared to red-wine production, white-wine production needs much greater control of oxygen, hygiene, yeast nutrition, and temperature. Thus, it is possible to produce an acceptable red wine in just “backyard” conditions, but it can be more difficult to make a high-quality white wine in the same environment [7
]. For example, white wine can be prone to oxidation; thus, sterile filtration must be used for proper stabilization. Chilling before bottling is required in order to precipitate excess potassium bi-tartrate salts, to reduce the formation of crystalline deposits during refrigeration. Additionally, clay can be used to remove proteins in the wine that can coagulate to form haze; this is especially true during storage and transportation, especially if the wine becomes warm. Copper sulfate is often used to remove hydrogen sulfide, which can be formed during yeast metabolism of proteins, which can occur during late fermentation [7
In contemporary society, consumers are demanding more environmentally friendly products. This includes food and drinks, such as wine. Companies are becoming more attuned to these demands, and are changing production processes, as well as entire supply chains, to achieve these ends. Some are even pursuing third-party sustainability certification, such as that offered through BCorporation (https://bcorporation.net
). Of course, implementing sustainability initiatives must make economic sense. Toward that end, life-cycle assessment and techno-economic analysis are two ways of quantifying and understanding business operations.
Life-cycle assessment (LCA) is the accounting of all environmental burdens associated with a product, a service, or a process, from raw material to waste/end-of-life [9
]. It was originally developed in the United States of America (USA) at the Midwest Research Institute around 1970 [10
], and the LCA approach as it is currently used was defined by ISO, including goal and scope definition, inventory analysis, impact assessment, and interpretation [11
]. To date, there are only a few published studies of LCA in wine-making processes and winery operations. For example, [12
] conducted a “cradle-to-grave” LCA (total LCA) to identify and assess the environmental burdens throughout the life cycle of a bottle of white wine, including grape planting, wine production, wine bottling, packaging, distribution, and disposal of the wine bottle. In their research, glass bottle production was found to be the most impactful to the environmental performance of the white-wine supply chain. In their analysis of agricultural production, including vine planting and grape production, vine planting was not negligible to environmental impact compared to the whole agricultural operation. [13
] also carried out “cradle-to-grave” analyses that included distribution. These authors also found that the production of wine bottles plays a very important part in the environmental effects of the life cycle of wine. Other studies also considered vine planting [15
], from which the vine planting contributed considerably to environmental impacts. Several other studies only conducted “cradle-to-gate” (i.e., the system boundary ended at the farm gate) research [15
]. They did not account for distribution in their studies. However, from their conclusions, glass-bottle production was still the most significant element that affected the environment. Even so, there is a dearth of literature that examined life-cycle assessment of vineyards and wineries.
Techno-economic analysis (TEA) is widely used in the food, bioprocessing, and chemical engineering industries. The usefulness of TEA for cost analysis, potential profit assessment, and production strategy determination was extensively demonstrated. For example, [18
] developed a cost model that utilized existing food factory data, and analyzed them systematically to understand various characteristics of unit operations in the food industry. Another TEA was used to characterize and improve dairy goat systems in Andalusia [19
], where a profitable production strategy was determined. In terms of wineries and wine making, however, only a few studies were published. [20
] developed an economic decision-making model for small to medium-sized wineries, and they found break-even prices ranging from $
3.50 to $
6.00/750-mL bottle for winery sizes between 5000 gal per year and 100,000 gal per year; the larger the winery size is, the lower the break-even price becomes. Furthermore, an economic cost model was developed to evaluate costs of raw materials such as grapes, labels, and bottles [21
]. They found that the cost of the raw materials had a substantial effect on the annual net profit; in this study, winery profits could fluctuate more than 60% when the grape price alone changed by 25%. Furthermore, [22
] compared different approaches to calculating profitability and productivity measures using a non-parametric technique. They found that none of the methodologies tested were significantly better than the others based on their evaluations of winery economic performance. Even though a few economic analyses were applied to wine making and winery operations, to the authors’ knowledge, there is no complete TEA for wine-making processes that was published.
Because of the paucity in the literature related to benchmarking vineyards and wineries, this study was carried out to examine environmental and cost impacts for red-wine production processes in the USA. The LCA encompassed vine planting to product distribution, while the TEA also considered this supply chain, but was conducted for small (5000 gal per year), medium (50,000 gal per year), and large (500,000 gal per year) wine production. It is our hope that this study can help move the industry forward toward greater sustainability by providing baseline information.
Production scale of wine production matters both for environmental impacts and costs. In terms of life-cycle assessment, bottle manufacture and wine making contributed the greatest share of energy consumption, while wine making was the greatest in terms of water consumption. For the output impacts, vine planting and bottle manufacture contributed the most to greenhouse gas emissions, while bottle manufacture and wine making contributed the most to solid waste disposal. Regarding techno-economic analysis, the relationships amongst annual costs for small (5000 gal per year), medium (50,000 gal per year), and large (500,000 gal per year) wine production exhibited a moderate exponential increase, although a linear increase appeared to fit better. The labor cost contribution to total costs decreased when production size increased, while the bottle cost contribution to total costs increased when production size increased. The annual revenues for small, medium, and large production scales also followed a moderate exponential increase, but a linear increase fit the data better. Again, the relationship between annual net profits and production scale was best described using a linear trend. The break-even prices were $4.55, $1.36 and $1.12/750-mL bottle for winery sizes of 5000, 50,000, and 500,000 gal/year; the larger the winery size is, the lower the required break-even price becomes. Further research is needed in order to optimize productivity, increase efficiencies, reduce environmental impacts, and minimize costs.