Decisions on Viticulture and the Environment
- In the field of viticulture, the OIV adopted a standard protocol for the clonal selection of vine varieties (Resolution OIV-VITI 564A-2017) that takes into account the progress achieved in the areas of scientific research and diagnostic techniques, as well as the different criteria that exist within the OIV Member Countries. Among the different points of the protocol, the term 'selected clone' is defined. Likewise, a number of parameters are described regarding the cultivation capabilities of candidate clones for vine varieties, such as phenological data, sensitivity characteristics and/or factors affecting resistance characteristics, yield parameters and quality parameters.
- Official guidelines for recognising grapevine collections at an international level (Resolution OIV-VITI 539-2017). These guidelines propose a series of criteria to be met with a view to establishing an international standard designed to harmonise the criteria for, and utility and efficiency of genetic resources. Vine collections that comply with these criteria will benefit from the recognition of the OIV and inclusion on the OIV list of varieties and vine collections available on the Organisation's website.
Decisions on Oenological Practices
Several resolutions relating to new oenological practices will be added to the International Code of Oenological Practices of the OIV, in particular:
- Treatment of musts with calcium sulphate for liqueur wines (Resolution OIV-OENO 583-2017). The objective of this practice is to develop liqueur wines that are balanced with regard to their taste sensations, to promote good biological evolution and satisfactory storage of liqueur wines, and to remedy insufficient natural acidity. The dose should not exceed 2 g/L calcium sulphate since this amount makes it possible to reach a pH of 3.2, which is a suitable level for the vinification of these musts. The residual sulphate content in the wines should not exceed the OIV limit
- Treatment of wines using selective plant fibres (Resolution OIV-OENO 582-2017). The objective of this practice is to reduce ochratoxin A levels in wines, as well as the number and levels of phytosanitary product residues detected in wines. Selective vegetal fibres are incorporated as processing aids, either during filtration with continuous deposition, or as a constituent of a filter sheet. The recommended dosage is determined according to the filtration technique used, without exceeding 1.5 kg/m2 of the filter sheet surface area.
- The treatment of musts with potassium carbonate, which has been permitted by the OIV within the context of the chemical deacidification of musts (Resolution OIV-OENO 580-2017). This new processing aid will be added to the list of products authorised for the reduction of the titratable acidity and the actual acidity.
- Treatment of musts and wines using inactivated yeasts with guaranteed glutathione levels (Resolutions OIV-OENO 532-2017 and OIV-OENO 533-2017). The objectives of these practices are to promote yeast metabolism through the provision of naturally-occurring nutritional compounds and to limit the oxidation of musts and wines by certain varietal aromatic compounds revealed by the metabolism of yeasts (particularly thiols). The dose used of glutathione – supplied directly or via yeasts with guaranteed glutathione levels – should not exceed 20 mg/L, in order to avoid any risk of reduction and the emergence of a yeast taste.
Decisions on Specifications of Oenological Products
The following monographs were added to the International Oenological Codex, in particular:
- An update to the monograph on Saccharomyces yeasts (Resolution OIV-OENO 576A-2017). Different forms of selected Saccharomyces yeasts may be used. Detailed specifications accompany this monograph, including the percentage of dry matter and the levels of viable yeasts according to the different forms. This monograph thus supplements the oenological practice.
- A monograph on non-Saccharomyces yeasts (Resolution OIV-OENO 576B-2017) used for the inoculation of grapes, musts and wines. As addition of non-Saccharomyces yeast might not result in the completion of alcoholic fermentation, inoculation with non-Saccharomyces yeasts may be followed by or complemented at the same time by inoculation with Saccharomyces spp. Detailed specifications accompany this monograph, including the percentage of dry matter and the levels of viable yeasts according to the different forms. This monograph thus supplements the oenological practice.
- An update to the monograph on tannins relating to the method for determination of polyphenols (Resolution OIV-OENO 574-2017). This method is designed to measure the polyphenol concentration of preparations of oenological tannins in polyphenols and is based on gravimetric analysis using solid-phase extraction (SPE).
- A monograph on glutathione that supplements the oenological practice (Resolution OIV-OENO 571-2017). Glutathione is used for its antioxidant properties that can fight against oxidation phenomena in musts and wines and protect aromatic compounds. Detailed specifications accompany this monograph, including that of the reduced glutathione content, which should be greater than 98%.
- A monograph on potassium polyaspartate (Resolution OIV-OENO 572-2017). Oenological potassium polyaspartate is exclusively prepared from L-aspartic acid. Detailed specifications accompany this monograph, including the degree of substitution of potassium salt, which should be at least 91.5% to guarantee optimal solubility.
- A monograph on selective plant fibres (Resolution OIV-OENO 578-2017). Selective plant fibres come from the edible parts of certain plants, generally of cereal origin. Selective plant fibres have a total insoluble parietal compound content of a minimum of 90% (m/m). Detailed specifications accompany this monograph, including the capacity for adsorption of certain pesticides, as well as that of ochratoxin A.
- A revision of the monograph on the PVI/PVP copolymer specifically relating to the maximum iron limit, which was brought up to 5 mg/kg of substance (Resolution OIV-OENO 605-2017).
Decisions on Methods of Analysis
During this same session, it was decided that new methods of analysis will be added to the OIV analytical corpus. These include, in particular:
- A method for the determination of 1,2-propanediol and 2,3-butanediol in musts and wines was adopted (Resolution OIV-OENO 589-2017). This method applies to the determination of the 1,2-propanediol and 2,3-butanediol that form after fermentation processes. These compounds are practically absent in unfermented musts, yet present in wine up to certain limits. The extracts are directly analysed via GC-MS on a polar column. The measurement is conducted according to the retention time and the mass spectrometer.
- A method of determination of the 13C/12C isotope ratio of glucose, fructose, glycerol and ethanol in products of vitivinicultural origin by high-performance liquid chromatography coupled to isotopic ratio mass spectrometry (Resolution OIV-OENO 479-2017). This type II method for glucose, fructose and glycerol and type III method for ethanol, based on the chemical oxidation of organic matter in CO2, makes it possible to determine the 13C/12C isotope ratio of the compounds using isotopic ratio mass spectrometry.
- A method relative to the determination of chitinase and thaumatin-like proteins in white wines (Resolution OIV-OENO 529-2017). This immunological method of semi-quantitative immunoprinting makes it possible to determine the presence or absence of unstable proteins in wines. Therefore, chitinase and thaumatin-like proteins can be detected from a total concentration of as low as 1 mg/L in wines.
With regard to spirituous beverages of vitivinicultural origin, three methods will be added to the OIV Compendium.
- An update to the method of determination of ethyl carbamate (Resolution OIV-OENO 590-2017). The principle of this method is based on the determination of ethyl carbamate in spirituous beverages by gas chromatography/mass spectrometry (GC/MS) coupling. This method applies to spirituous beverages and spirits of vitivinicultural origin whose dry extract is either lower or higher than 20 g/L.
- • On the one hand, there was the introduction of the definition of 'apparent alcoholic strength' (AAS) (Resolution OIV-OENO 587-2017), which is equal to the number of litres of ethanol contained in 100 litres of hydro-alcoholic mixture with the same density as that of the alcohol or spirituous beverage. Therefore, the AAS is directly deduced from the density of the product, without distillation. The AAS is expressed in % vol. On the other hand, there was the introduction of the principle of obscuration (Resolution OIV-OENO 588-2017), which is defined as the difference between the real alcoholic strength by volume and the apparent alcoholic strength, expressed in % vol.
Decisions on Economy and Law
- The OIV also adopted a recommendation for the establishment of training programmes for sommeliers (Resolution OIV-ECO 568-2017). Sommelier training programmes should guarantee that the sommelier acquires skills and is capable of diligently fulfilling the role as described in the Resolution OIV-ECO 474-2014. In accordance with the UNESCO International Standard Classification of Education (ISCED), the minimum sommelier training programme may be defined as a Level 4 post-secondary non-tertiary education programme or professional certification of equivalent level that prepares for entry into the labour market. The minimum duration will be 600 teaching hours distributed according to the specified curriculum.
- • Finally, the OIV adopted a resolution on the application of sustainable production principles in the production of distillates, brandies and spirituous beverages of vitivinicultural origin (Resolution OIV-ECO 501-2017). This document provides recommendations for the implementation of the five general principles of sustainable production in vitiviniculture, as they are defined in Resolution CST 518-2016. The document also covers the production process of distillates, brandies and spirituous beverages of vitivinicultural origin as they are defined in Part 1, Chapter 7 of the International Code of Oenological Practices.
The full texts of the resolutions adopted by the 15th OIV General Assembly will shortly be available on the OIV website.