Does osmotic distillation change the isotopic relation of wines?

¹ Hochschule Geisenheim University von Lade Straße 1, 65366 Geisenheim, Germany
² Instituto Nacional de Vitivinicultura, Dpto. Estudios Enológicos y Sensoriales San Martín 430 – City, Mendoza

^a Matthias.Schmitt@hs-gm.de
^b marcelo_murgo@inv.gov.ar

Abstract

Currently partial alcohol reduction of wine is in the focus of research worldwide. There are several technologies available to achieve this target. These techniques are either based on distilling or membrane processes. Osmotic distillation, one of the possibilities, is a quite modern membrane process that can be used. During that process, wine is pumped in counter flow to water along a micro porous, hydrophobic membrane. The volatile components of the wine can permeate that membrane and are dissolved in water. The driving force of that process is the vapor pressure difference between the volatiles on the wine and water side of the membrane. The aim of this work was to determine if the alcohol reduction by osmotic distillation can change the isotopic relation in a wine. Can this enological practice change the composition of a wine in a way that an illegal water addition is simulated? Different wines were reduced by 2% alcohol v/v with varying process parameters. The isotopic analysis of the O 16/18 ratio in the wine were performed according to the OIV methods (353/2009) These analyses showed that the isotopic ratio is modified by an alcohol reduction of 2% v/v in a way that corresponds to an addition of 4–5% of external water.