16 Mar Increasingly better South Tyrol reds thanks to Air Mixing MI

Increasingly better South Tyrol reds thanks to Air Mixing® MI

That wines of great quality and finesse are produced in South Tyrol is a well-known fact. Andrea Moser, Oenologist from the Cantina di Caldaro, experimented with Air Mixing M.I. for the 2020 harvest. With him, we explore how the quality comes as a result of continuous improvement and the precise and timely choice of each and every technological and operational detail.

In the maceration of red grapes, the AirMixingâ MI system is based on the introduction of small jets of compressed air in a combined, sequential and modulated manner, through a series of nozzles positioned on the wall of the tank. The pulses and air jets follow precise sequences and transmit motion to the liquid such as to create a disintegrating wave responsible for the break-up, inundation and immersion of the cap, as well as eradicating the gradient of heat distribution, density and extracted components.
Preventing the formation and compaction of the cap until the end of the initial phases, the marc remains soft, mixing with the liquid throughout the entire vinification process, at the end of which it is still easily pumped, with a substantial reduction in time and difficulties associated with the drawing off operations. Since its inception, Air Mixing MI has revolutionised the concept of red grape maceration, optimising the extraction of the noblest components from the skins in a homogeneous way and in tanks of any shape, material and size. The functionality, safety, cost-effectiveness and energy-saving features resulting from a better distribution of temperatures and the reduction of maceration and drawing-off times, combine with the evidence of the oenological result, leading to stable and well-aligned wines that satisfy the quality and market objectives for wineries and oenologists all over the world. Thanks to Air Mixing and the plasticity in programming the parameters in play, this extraction technique and technology adapts to the grapes to produce wines that are always able to please the expectations of territoriality and enjoyment.

We discussed these factors with Andrea Moser, Oenologist from the Cantina Kaltern (Caldaro) in South Tyrol. Following the cellars being renovated and expanded in 2017, he continues to introduce new technologies to improve the quality of the wines and the working conditions of the operators.

In addition to the Pinot Blanc and Sauvignon Blanc varieties typical of the region, the winery is known for its reds and above all, the Schiava – the only DOC grape variety of Lago di Caldaro – along with its Pinot Nero, Lagrein, Merlot and Cabernet Sauvignon. Positioned between 200 and 700 metres above sea level, the large division of 450 hectares cultivated with extreme care by the 650 members of the cooperative requires not only time-sensitive organisation of the management of the conferment but also the perfect optimisation and rationalisation of works and spaces available in the cellar.
For the 2020 harvest, the winery conducted a number of tests on red grapes with two tanks fitted with Air Mixing, associated with temperature control and micro- and macro-oxygenation. The objectives were to optimise extraction and rationalise certain critical issues regarding manpower.
“The tanks for the vinification of red grapes range from 150 to 350 quintals and have a geometry that is not particularly favourable for the formation of the marc cap, being rather tall and narrow,” says Moser. “As a result, the caps tend to be thick with very stratified temperatures and pumping over is less than ideal. Despite the good ripening conditions, the health of the grapes, the many pumpovers and délestage, I still could not achieve the extraction results I wanted. What’s more, the many operations required necessitated a lot of labour, with the risk of non-homogeneous results and considerable fatigue for the workers. With many tanks, completing a délestage once or twice a day combined with the continuous use of pumps for pumping over, working on the tanks in the cellar had become quite unsustainable. The first objective I was seeking to achieve with the introduction of Air Mixing was greater and better extraction, in a more standardised way in order to have the safety of a repeatable result. The second was to automate as much as possible in order to reduce chance in the operations most related to the human factor. Added to this was the quite significant possibility of being able to automatically dose macro-oxygenation during fermentation and in subsequent phases. At the end of this initial experience, I was truly satisfied with the results that have allowed us to reach and exceed expectations. With the 2021 harvest, the system will be implemented on 13 additional tanks.”

New experiences and new protocols

Along with the fermentation temperature, the intensity and frequency of injections are the three parameters on which to play with Air Mixing so as to define the most suitable extraction protocols for the specific grapes.
“Yet, unlike what you might think,” explains Andrea Uliva, Parsec’s own Oenologist, “intensity is not the most important aspect. Once the system has been calibrated on the geometry of the tank and the initial or final stages of fermentation have been differentiated, the amount of air injected with each pulse remains almost constant.”
It is not the size of the bubbles nor their speed that produces the effect and determines the efficacy of the extraction (as per all other compressed gas techniques) but rather the ability of the disintegrating wave to break up the marc cap and to mix the solid parts with the liquids, facilitating the diffusion and leaching of colour and tannins that pass from the skins to the liquid component.
“Air Mixing is an entirely new concept in maceration. When approaching this new technique, from pumping over or délestage, oenologists obviously need to hold off on their way of working and understand how to adjust the extraction according to the objectives, the grapes, the sensitivity and the style. There are those who are seeking speed and extraction of colour then there are those who are after a more tannic extraction”, explains Uliva.
As Moser confirms, this combination of factors requires – as always – an early setup period to identify the best programming. “In determining the settings of the initial phase, I started out cautiously but later on, it was clear that the extraction obtained with Air Mixing is not aggressive, as it might seem at first. And at the same time, it is necessary to understand that greater turbidity – consisting of fragments that generally remain attached to the skins – does not mean an increase in the risk of reduction, since the lees always remain fragrant and the wines much more open, even during fermentation,” explains Moser. “Here, we are talking about a different and entirely new way of working. If you really want to refine the final objective, it takes a bit of work but once you find the right system, you can be sure that this is 100% repeatable. Indeed, after some initial reasoning, I achieved the results I wanted. Air Mixing is a system that offers great elasticity. You can decide how to extract and how much to extract, choosing how often to homogenise or whether to adjust the extraction depending on the temperature, taking into account that the control is accurate and real. If in the maceration of a Pinot Noir, for example, in a system for pumping over, I set 25 or 28° Celsius, with the risk of reaching 35° in the marc cap and an extraction not in line with that desired, with Air Mixing and with the dual probe control, I can set 30 or 32° Celcius, be sure that this is the temperature inside the cap and consequently, work on the characteristics of the extraction.”

Optimal extractions and reduced wait times for the wines

Of course, the end result and the quality of the wines are key in determining the most important techniques applied in the cellar and, explains Moser, in the vinification of the grapes destined for both the classic line and the company’s crus, Air Mixing MI did not disappoint. “The wines I achieved in tanks equipped with Air Mixing are richer at a tannin and taste level. Undoubtedly, I managed to extract what I needed, which I could not achieve prior using traditional techniques, especially for Pinot Noir and above all in the early stages.”
“Typically,” adds the South Tyrolean Oenologist, “I am not a fan of extra-long macerations and I do not like to leave young wine unattended on the marc for too long. But at the same time, I always have pretty fast fermentations, so the goal is to quickly extract everything I need. With Air Mixing, I extracted much more in less time and, having verified that what I was extracting was good, I was able to slightly lengthen the maceration times until the end of fermentation and achieve better results.”
Also from an aromatic point of view, the results are encouraging. The wines were open and stable aromatically so as to reduce the number of rackings normally needed after drawing off, in order to counteract the natural tendency to reductions that certain varieties (such as the Schiava or Pinot Noir) manifest in the initial stages of processing.
Wines that are more ready and responsive to the objectives of the oenologist are thus – thanks to the aromatic equilibrium and colour stability – possible also due to the rational and combined dosage of macro-oxygenation carried out continuously during the fermentation phase.

Experiences around the world

Thanks to the appreciation of the Air Mixing system in cellars around the world – varying in terms of size, structure, objectives and products – the experience and applications of the system are gradually multiplying. The advantages in terms of quality and organisation of work are often evident from smaller to larger realities where, as Andrea Uliva confirms, the new system has at times been able to revolutionise long and complex operations such as the drawing off of very large tanks or solving problems related to structures designed with quality objectives that are no longer current.
“In San Diego, California, for example, we installed Air Mixing in a Custom Crush [a company that vinifies batches of grapes on behalf of third-parties – Ed.] on tanks from 200 to 3000 hl. In the latter, before the installation of Parsec’s Air Mixing MI, drawing off usually took place by homogenising the wine with the marc of the cap with a continuous and intense spraying of the cap whilst pumping the solid-liquid mixture through a valve, resulting in the formation of a great deal of lees. The introduction of Air Mixing MI, which in some cases replaced air replacement systems of another type, permitted a greater respect of the integrity of the skins that remain mixed in with the liquid component without compacting, whilst also dramatically reducing the time of the operation to one third of that required previously. To give another example, in certain establishments with very large tanks without air conditioning and outdoors, the action of Air Mixing has been able to remove much of the heat that accumulates in some areas of the tank, lowering the fermentation temperature by several degrees and reducing the risks of a stuck fermentation.”
But even in the pre- and post-fermentation phases, the experiences within the various wine-growing regions highlight the versatility of the machine that, with just a few adjustments in programming or orientation of the nozzle, can be used in the thermo-vinification of red grapes, the re-suspension of lees in the maturation of white or red wines on the lees.
The modulated injection of Air Mixing is thus an entirely new tool regarding which – as evidenced by the experiences of oenologists and cellars using it – an increasing number of advantages and opportunities are being discovered, whilst simultaneously adapting the protocols to the objectives. This is something akin to the revolution that, we imagine, took place in the cellars in the early 1900s with the advent of pumps.