Does an ideal parameter exist to determine the dose of oxygen to be administered to each wine with micro-oxygenation?
The answer is no, it does not exist simply because the ideal dose does not exist. We could also respond with another question: does a perfect wine exist?
A different management of the oxygen and micro-oxygenation leads to wines with diverse characteristics, which correspond to an “ideal” depending upon the sought-after style, the market to which it is targeted, but also by the character, the perception and the objectives of the producer.
In reality, speaking of a technique (and not entering into philosophy) it is nonetheless helpful and necessary that those who apply it may have as a reference one or more parameters to monitor the effect and efficacy of that occurring, but also to keeping the risks under control and managing them should they eventuate.
As with every other process, it is necessary to have instruments of control, measurable through indices and parameters (the so-called process parameters) that vary in an unambiguous means and which enable the winemaker to make their decisions.
In fact, as we know (or else we invite you to read Oxygen and Wine by Biondi Bartolini, Cavini and De Basquiat, Parsec ed.), oxygen intervenes in so many biological and chemical processes and aspects of wine. Until now a single parameter had not yet been identified with which to quantify the oxygen requirement of a wine nor the dose of oxygen to administer and neither by which one can foresee with its evolution the attainment of the desired profile or objective.
Risks under control
The process parameters necessary for risk management are those that consent the handling of oxidative and microbiological peril and are valid not only (and not so much in dealing with administering microdoses) in micro- and macro-oxygenation but also and above all in each of the phases where the unchecked access of oxygen to the wine (unit operations, handling, transport, etc.) is possible.
The parameters to be kept under control are:
- the free sulphur dioxide (or better yet, that in molecular form, active against microorganism contaminants and which depend on the pH of the wine),
- the temperature (at lower temperatures oxygen solubility increases whilst its consumption decreases!) and,
- only in the case of elevated doses of oxygen, also the eventual accumulation of dissolved oxygen.
It should be highlighted that whilst maintaining good protection with sulphur dioxide or interrupting the oxygenations at low temperatures prevents the risk of oxidation, the detection of a dissolved oxygen accumulation consents only to evaluate and a posteriori the exactness of the applied dose or, better yet, the existence of an overdose situation.
And to know the dose and monitor the process of micro-oxygenation, or rather the conformity with the sought-after objectives?
The ideal process parameter for the micro-oxygenation technique would be that which consents above all the definition of the starting dose and from whose evolution one could obtain the necessary information on the progress of the process until reaching the desired objective.
Seeing as how the mechanisms of oxygen consumption in red wine involve the polyphenolic compounds, all researchers who have dealt with this subject have used such indexes as those chromatic and spectrophotometric, or more finely quantifying the polyphenolic compounds of the wine with the techniques of HPLC analysis.
In addition to these, in practice the parameters utilised the most are of an organoleptic variety, for which monitoring is possible only with the application of a well-defined quantitative method.
The development of a model for evaluating and managing the oxygenation of red wines: MOXEasy
Having verified that it is difficult to pinpoint a single analytical or sensorial parameter able to satisfy all the necessities of managing the oxygenation technique, Parsec has embarked on the path of developing a logical-mathematical model.
A series of analytical and organoleptic parameters have been selected and monitored frequently on all wines subjected to micro-oxygenation throughout the years spent perfecting the system.
The data collected was examined on the basis of the sought-after oenological objective, defining two diverse levels of oenological impact potentially requested by the micro-oxygenation technique:
- a low impact, more respectful of the varietal character and with greater objectives of stabilisation rather than improvement
- an elevated impact, able to develop olfactory and gustatory characters of “global appreciation” and to provide more ready wines, with the aim of “improvement” treatments.
Everyone is free to choose on the basis of their own tastes, markets and aims of the objective with which to apply an oenological treatment. To know what we think, we have already discussed it here.
The definition of the oenological objective and the dose of equal impact sought-after is naturally based:
- on the varietal characteristics;
- on the characteristics of the raw material given by the phenolic maturation;
- on the typology of the final product;
- on the techniques of refinement adopted (for example, if in a vat with or without the use of wood derivatives or if in barrique);
- on the time available.
In this way, commencing with the same wine it is possible to foresee various paths, each of which leads to a type of product, defined on the basis of the desired impact through the application of the micro-oxygenation technique.
In the choice of analytical parameters to be inserted in the model were selected easily-determined indices, characterised by good reliability, rapidity and a positive diffusion within the laboratories of oenological analysis.
The realisation of the database and the development of a self-learning algorithm (with the insertion of new data improving precision in defining the dose), able to interpolate the analytical and sensorial data with the sought-after objectives, has led to the creation of a software for the evaluation of the oxygen dosage, validated in the management of micro-oxygenation of red wines.
The final product of the model developed is the MOXEasy, available to users of Parsec micro-oxygenators, in which analytical data, the sensorial features, the characteristics of the raw material and the desired effect represent the inputs inserted into the program, which seeks out within its database the typical wine profile that presents the best affinity and provides the user with the ideal dose for the desired objective.by