Grapevine & Wine 02/05/2011

Shipping wine over long distances. What changes in the sensory profile?

Why a wine tasted in countries other than the home one can have organoleptic characteristics very different from the original? The effects of transport on red and white wines are very different

It is common experience that a wine tasted during a holiday has different flavors and aromas (often more fascinating) than the same wine brought home or bought in a wine bar away from the production site.

The suggestion of the holiday, as well as the psycho-physical state associated with it, can certainly contribute to this, but there are other factors related to wine storage during transport, particularly on long routes or by sea.
Understand how the wine evolves or devolves during an expedition is essential to ensure customer satisfaction. In particular, the sensory changes associated with elevated storage temperatures are of great concern to both producers and consumers.

If in cellars and in stores there are strict control systems, temperature and humidity during transport undergo highly changing conditions, even if the manufacturer has taken steps to reduce the thermal shock. Even in thermal containers the temperature of a wine can vary of 8 degrees. In ships, especially during the summer, the temperature inside the container can be 20 degrees above room temperature and day / night variation can be above 10 degrees.

An Australian study allowed understanding in more detail what impact different storage conditions have on the sensory profiles of white and red wines. Four whites and four reds were exposed to four different storage conditions for creating 32 conditions. Riesling, Gewürztraminer, Sauvignon Blanc and Chardonnay came from the same manufacturer and were of the same vintage. A Merlot and three Cabernet Sauvignon had different labels from the same manufacturer. The wines were kept at 20 ° C, 40 ° C, 20/40 ° C (simulating the daily alternation in temperature) and also included a sample placed in the trunk of a car for three weeks (average temperature: 15 degrees).

As for white wines, both the 20/40 ° C and especially the 40 ° C conditions induced a change in the flavor profile that passed from floral and citrus notes to aromas more typical of older wines, such as butter, honey, vanilla, tea and tobacco. As the temperature rose further, also unpleasant sensations of diesel, rubber and oxidize were noted. In this study, samples exposed to higher temperatures tended to have higher concentrations of TDN and vitispirane 1 and 2 and lower concentrations of isoamyl acetate, Hexyl acetate, and 2-phenylethyl acetate, in agreement with previous research on wines stored at high temperatures.

For red wines, the influence of temperature on the sensory profile was less keen and it was associated with the decrease of fruit and vegetables aromas. The typical aging aromas, such as tobacco, honey and vanilla, were not meaningfully increased. In particular, with the most extreme condition of a constant temperature of 40 ° C, the researchers noticed low concentrations of linalool, ethyl octanoate, nonanoate, decanoate, edodecanoate, methyl octanoate-e- decanoate, isoamyl octanoate-e-decanoate, isopentyl hexanoate, and 9 - ethyl decanoate and higher concentrations of ethyl 2-furoate, ethyl phenylacetate, oxide dehydroxylinalool A, p-cymene, TDN, and vitispirane 1 and 2.

The concentration of isoamyl acetate decreased with increasing temperatures and the level of SO2 had no apparent effect during the storage period.
Both the sensory and chemical analysis showed significant differences for the wines stored at higher temperatures.

di Graziano Alderighi