Behind the aroma and flavor of good wine, there is a complex production process that begins in the control of the vineyards and culminates in the bottling of the wines. In a large part of winemaking, adequate refrigeration is key to guaranteeing the quality and organoleptic conditions of each specific specimen. Hence, the most prestigious firms in the wine industry make sure they have cooling and air conditioning systems for their wineries.
The wine industry and the factors that influence the quality of wine
In general, there are a number of factors that influence the quality of wines:
- To begin with, there is the strain of the grape and its origin. For example, in Spain, Tempranillo and Airén are the most cultivated and processed by the national wine industry. To such an extent that almost half of the Spanish vineyard surfaces are dedicated to these varieties. These strains are native, but so are Bobal, Macabeo, or Pedro Ximénez, among many others.
- The environment where it is grown is also important. Called by experts “terroir“. Specifically, this brings together the characteristics of the soil, the height of the terrain, the climate and average temperatures, the soil, and the growth process. These are factors that also affect the flavor and final characteristics of the wines.
- The method used in production.
- Likewise, the production process in cellars.
- Last but not least, are the thermal and hygrometric conditions inside the facilities where the wine is produced and where the different production processes take place.
What aspects must be controlled in a wine cellar?
As we will expand on later, in certain stages of wine production it is essential to control the temperature of the product according to the type of wine to be made. For this purpose, having appropriate refrigeration systems is essential to adjust the temperature and optimize the aroma, color, and quality of the broth in general.
On the other hand, storage under specific conditions is key to achieving optimal conservation and maturation of the product. Otherwise, the fundamental properties of the wine (maceration, smell, and taste) would be irreparably spoiled. In this sense, the wineries in which wines are made and stored must have characteristics that protect them from external factors that have a negative influence.
In summary, the factors to control in the wineries that make up the wine industry are:
- Ventilation and indoor air quality.
- Relative humidity.
- Lighting intensity.
- Noises and vibration.
Refrigeration during winemaking, is key in the wine industry
As we have said, maintaining adequate temperatures at each stage of production is critical to guaranteeing the quality of the wines. Below we will review the ideal conditions that the wine industry must control during each phase:
- Ethyl fermentation. This consists of a biological process carried out in the absence of air. During this stage, alcohol (ethanol) and a large amount of carbon dioxide (CO₂) are generated. When it comes to the ethylic fermentation of white wines, the required temperature range is generally between 10°C and 15°C. For their part, the reds need between 20°C and 30°C.
- Malolactic fermentation. It is an essential process to eliminate microbiological cloudiness, oxides, and chemicals. The refrigeration units applied during it are called forced stabilization. In short, these produce rapid cooling until reaching temperatures below 0. The aforementioned systems maintain this level of cold for a few days in thermally insulated tanks. This makes it possible for solid substances to settle and can be extracted later.
- Regarding the following stages of production, the air conditioning of the spaces where the wine is made is a priority. Depending on the type of wine, the range of temperatures to maintain is between 13°C and 17°C. On the other hand, the humidity must be within ranges that we will specify later.
Temperature control during maceration and wine aging
In particular, to control ethylic fermentation, companies in the wine industry have water-cooling facilities. Otherwise, high fermentation temperatures would result in wines with low alcohol content, high acidity, and little aroma. Normally, the tanks for fermenting wine are made of stainless steel. In their central part, they have an attached coil through which cold water recirculates at temperatures between 7 and -10ºC. These will depend on the type of wine and the stage of the fermentation process.
Likewise, the aforementioned deposits give off heat directly to the enclosure during the fermentation. It is added to the thermal loads that depend on the season of the year and other factors. For all these reasons, the installation of water chillers and their fan coils in these spaces is essential for the wine industry.
Temperature control in the aging process in the wine industry
At this point, it is necessary to remember the classification of wines based on their maturation and aging time in the cellar:
- Breeding. The reds have a total aging time of 24 months, of which at least six must be in oak barrels. For whites and rosé, the minimum total maturation is 18 months, with at least six of them in barrels.
- Booking. In this category, red wines must complete a total aging period of at least 36 months, with a minimum of 12 months spent in barrels. For whites and rosés, the relationship would be 24 months of aging, with a minimum of six in barrels.
- Great reserve. To be precise, wines in this range require a minimum maturation period of 60 months, 18 of which must remain in the barrel. For their part, the gran reserva whites and rosés require a total aging time of at least 48 months. Of them, the first six must take place in the barrel.
Apart from the above, there is a category of young wines or of the year, with a maturation time of no more than 6 months.
In all cases, the air conditioning of the cellars is essential during the maturation and aging period. A suitable system for this purpose allows to regulate of the temperature, keeping it at constant values and controlling the humidity in these enclosures, while the wines remain in them.
Ideal conditions for wine storage
It should be noted that in the wineries where Crianza, Reserva, and Gran Reserva wines are stored, the ideal conditions would be:
- Temperature from 14 to 17ºC stable.
- Percentage of relative humidity between 75% and 80%.
- Low airspeed, almost zero.
- Constant air renewal to eliminate CO₂ and undesirable odors.
In order to maintain optimal temperatures, companies in the wine industry require cold water production units and fan coils. Bearing in mind that cold systems tend to dehydrate spaces, an extra moisture supply is necessary. Otherwise, there could be significant losses in the content of the barrels, approximately between 4% and 7% per year. However, excessive moisture can lead to the growth of mold and mildew.
We design and develop the refrigeration systems required in the wine industry
At Intersam we manufacture everything from water coolers and fan coils to forced stabilization systems for malolactic fermentation and air conditioning units for your winery. Since 1995, we have been designing complete refrigeration and air conditioning systems for industry and commerce, totally customized.
Are you incorporating new wineries to expand your wine varieties? Do you want to renew the cooling and air conditioning systems of your facilities? Contact us and we will attend to your project inside and outside of Spain. We also offer the best cold solutions for the wine industry, with state-of-the-art technology to provide maximum effectiveness and energy efficiency.