Creation of a European data bank on isotopic NMR-data of wines Tasks and problems of the wine controllers
The addition of sugar to grape-must or to partially fermented wine to raise the alcohol content of the wine is subject to legal limits. Such sugaring can now be proved with certainty by measuring relative quantities of the hydrogen isotopes present in the sugar and alcohol of a wine. This NMR measurement technique (SNIF NMR) is based on the fact that there is less deuterium in beet sugar than in grape sugar. It also enables watering of wine to be detected. The best available chemical techniques are of very limited use, because for every test they require, as a control sample, an identical wine known beyond doubt to be authentic. But the amount of deuterium in grapes depends only on geographical location and climate, so that it is now possible to take grapes from a representative selection of locations, make wine samples in the laboratory and carry out SNIF NMR measurements on them. The test results can then be used to build up a data bank of comparable values for reference. The Commission of the EC has given the Joint Research Centre in Ispra the task of setting up such a data bank for Europe. A draft directive seeks to standardise the procedures for taking, handling, storing and preparing all samples for the data bank. The various national authorities are recommended to collect additional data for musts and for authentic wines. They should also aim to be capable of carrying out all spot checks using their own NMR equipment.
Bibliographic Reference: Paper presented: Meeting of German Wine Experts and Wine Controllers, Eltville (DE), May 15-17, 1990
Availability: Available from (1) as Paper EN 35480 ORA
Record Number: 199011495 / Last updated on: 1994-12-02
Original language: de
Available languages: de