Every ambitious winemaker or brewer today knows that temperatures play an important role in the production of wines, beers and all kinds of alcoholic beverages. And the fermentation is the birth of the later beverage. Gone are the days of simply placing a loose water hose or damp towels on top of your fermentation tanks. Properly adjusted temperatures ensure the quality of the products, while too high temperatures can impair it or even cause the product to “overturn”. Today, market-driven quality can only be achieved with temperature-controlled processes. The key to this is the correct temperature control during the production process. But what that means has remained in the background for many.
First of all: It doesn’t work without cooling – but cooling alone is not enough either
Some producers think they only have to use a water hose or a cooling coil – and the basic requirement for a good fermentation process would be met. This view falls short. It depends on precise temperatures at the various stages of fermentation – this includes the phase of storage and preparation. Because only this increases the quality and opens up possibilities to positively influence the character and taste of the products. Important: continuously monitor the fermentation activity, don’t leave the fermentation to its own devices, but lead it to its goal as part of a fermentation process. If you don’t control the fermentation, chance reigns supreme in your products.
Temperature-controlled fermentation – what does that mean?
In order to bring wines, beers or alcoholic beverages to full bloom, a holistic understanding of “fermentation” is crucial. This includes the entire winemaking process. There are different cooling requirements for different process steps. Temperature regulation is the central control element, because temperature-based fermentation control means target guidance. In this sense, the end product can be influenced at all stages of the process and optimized towards a desired goal: Higher temperatures can increase the complexity and aroma of the products, while lower fruitiness and acidity can promote them. As long as the fermentation and maturation phase lasts, several hundred other chemical compounds can be formed in addition to alcohol, which influence the bouquet and the sensory taste. In order to produce uncompromising and reproducible quality, you need not only correctly designed cooling elements, but also professional fermentation control with high-precision temperature control.
The various (temperature) stages of wine development (fermentation stages)
In simplified terms, the production process for alcoholic beverages can be divided into the following stages of wine development or fermentation, often with different temperature profiles. Digital cooling systems with precise controls and regulations from LiquoSystems provide good service here:
• Temperature-controlled storage and fermentation phase, if necessary, with yeast preparation
• Temperature-controlled fermentation (main fermentation phase)
• If necessary, temperature-controlled second fermentation for red wines (malolactic fermentation) or for beers (for carbonation)
• Temperature-controlled post-fermentation phase (and also storage phase)
Even after pressing, the must can be prepared accordingly through the targeted use of temperature and designed for the target. Controlled cooling, for example, can increase the yield for the later aroma.
In general, one speaks of the following guide values, from which the professional can of course deviate calculated in individual cases. The information is given here in grams of sugar per liter, since this unit of measurement is the same in all of our customers’ countries. Otherwise, in Germany, Switzerland and Luxembourg they speak of Oechsle (Oe), in Austria and Hungary of Klosterneuburger, in France of Beaume and in Spain of Brix.
Initial fermentation and main fermentation phase: Ferment quickly, but not too quickly
The general rule is: Ferment quickly, but not too quickly. A “tumultuous fermentation” is not the first choice. The fermentation phase lasts until the first 25 g/l of sugar have fermented. In the main fermentation phase, the sugar is fermented down to 50 g/l. Of course, the tempering in the main fermentation phase is most influential for the subsequent character of the product. For beers, the temperatures for top-fermented beers are around 10 degrees below those for bottom-fermented beers. White wine, for example, is usually fermented between 15 and 18 degrees Celsius, red wine between 22 and 25 degrees. But what does between mean? A degree here or there can make a big difference! And this is how producers can tease out nuances with know-how, craftsmanship and high-precision cooling systems. But even in the post-fermentation phase, some effects can still be achieved if you only know how to use the keyboard of the temperature.
Depending on how the wines are aged, a second fermentation (malolactic fermentation) follows for red wines. Here, the malic acid is converted into the milder lactic acid. In order to start this in a targeted manner, the container may have to be warmed up in a controlled manner.
For all wines, the post-fermentation phase follows with many oenological options. Here, too, temperature control plays an important role in maintaining the desired storage temperatures. For example, to keep white wines sparkling with the remaining fermentation carbonic acid.
Here is another example of different temperatures in the main fermentation of white wine and red wine
The white wine starts:
During cold fermentation (14 to 16 degrees), approx. 10 to 15 g/l of sugar are broken down per day, which corresponds to 4 to 5 Oe. With controlled fermentation (18 to 20 degrees), approx. 20 to 30 g/l of sugar, i.e. 8 to 10 Oe.
Now the red wine:
With controlled fermentation (20 to 23 degrees), approx. 20 to 30 g/l of sugar are broken down per day, i.e. 8 to 10 Oe. During warm fermentation (25 to 28 degrees), around 50 g/l of sugar or even more are broken down per day, i.e. at least 20 Oe.
Fermentation processes can be so different, and so must the temperature control!
Are you looking for the sure way to better products?
Would you like to know more about the right fermentation control, the right fermentation cooling systems and the technical design, especially for YOUR products? >> Talk to us!