The conditions under which wine is stored and transported can have a major impact on its sensory properties once it reaches the consumer. There are a number of factors to be considered: bulk vs packaged transport, temperature, humidity, light exposure and bottle orientation. Legal aspects also need to be taken into account. The AWRI recommends that wine producers obtain independent advice regarding legal contracts and where liability sits during the transport and storage of wine, prior to and after packaging. The AWRI further recommends that hold back samples are retained and stored under known conditions so they can be used for comparison in the case of any problems arising during transport or storage.
Ownership during transport
As wine can be damaged in transit to the customer it is important to note who is responsible for the wine during transport. Ownership and responsibility for the wine are dependent on if the wine is quoted as FOB – Free on Board (Port of Shipment) or as CIF – Cost, Insurance and Freight (Port of Discharge). When goods are quoted FOB, it is the exporter’s responsibility to deliver the consignment to the ship at the port of shipment, to bear all costs incurred in doing so, with delivery completed when goods are placed on board and liability ceasing for the exporter when goods pass the ship’s rail. The buyer is then responsible for the cost of freight, insurance and all charges thereafter until they arrive at the buyer’s warehouse. Under a CIF contract, the exporter’s responsibility includes all the costs applying in the FOB contract plus the cost of the ocean freight and insurance, with liability ceasing when the goods pass the rail at destination. The buyer is then responsible for all costs beyond that point. More information can be found in the Wine Australia compliance guide, which includes advice on export and shipping of pallets of wine (p19).
Information on shipping services out of Australia can be found at the following links:
- Australian Freight Councils Network
- Australian Trade and Shipping
- Logistics Association of Australia
Results from bulk wine transport trials
The AWRI worked with collaborators to conduct several trials that shipped more than a million litres of wine in bulk from Australia to the UK under different conditions (different shipping routes, filling temperatures and bulk container types). Over a 15-month trial period, a wide range of analyses were performed on the wines, including temperature monitoring, sensory testing and chemical analyses. Some of the key outcomes of the trials were:
- Type of shipping container (ISO versus flexi) – A panel of experienced winemakers showed no consistent sensory preference for wine transported in ISO tank or in flexi tank.
- Flexi tank filling temperature – No sensory differences were observed in a Chardonnay wine filled into flexi-tank at low (8°C) and high (19°C) temperatures after ~44 days travelling a southern to northern hemisphere transport route.
- Shipping route – There were no significant sensory differences between wines that had been transported in flexitank directly compared with those that had been transhipped (transferred from one ship to another in Malaysia).
Australian grape research or wine grape levy payers can obtain a password to access the full report on these bulk wine transport trials by contacting the AWRI helpdesk on email@example.com or (08) 8313 6600.
Bottle orientation during transport and storage
One factor to be considered during transport and storage of bottled wine is the orientation of the bottle – that is, whether bottles are stored upright, horizontally or inverted. Numerous studies have investigated the developmental characteristics of wine under differing alignments. Mas et al. (2002) investigated the impacts of different alignments on bottles sealed with six different closures for a white and red wine. As a general rule, after 24 months wines stored upright had higher yellow/brown colour (measured by OD420nm absorbances) than those stored horizontally; however, the differences were not significant. The study showed that oxidation was higher for upright samples sealed with agglomerated cork stoppers, with elevated acetaldehyde levels seen in white wine samples from the 3-month timepoint onwards. In another study, Skouroumounis et al. (2005) investigated the developmental characteristics of a wooded Chardonnay and Riesling wine, with samples stored under differing orientations. Based on the testing undertaken, including yellow/brown colour (OD420nm), ascorbic acid and sensory analysis, the bottle orientation (horizontal or upright) was shown to have little effect on the chemical composition and sensory properties of the two wines across a 60-month period.
Effects of temperature, humidity and light on bottled wine
The conditions under which bottled wine is stored play a major part in how a wine ages and evolves sensorially. Excessive storage temperatures will have a marked effect on the shelf life of bottled wine and can see rapid ageing and significant deterioration of the product. Marais (1986) observed the development of faulty flavours and decreasing overall quality after 12 months’ storage of wine at 30°C. Temperatures in excess of 40°C will induce visual and sensory changes to a wine in only a matter of days (Ough 1986). In general, any storage place where the temperature exceeds 25°C for long periods and 40°C for short periods can affect wine quality (Ough 1992). Amon and Simpson (1986) recommend that bottled wine be stored with the cork in contact with the wine in a cool (15–20°C), dry location.
Thermal cycling where the temperature varies significantly between day and night should be avoided (Hirlam 2019a,b). Leakage of wine and/or movement of cork stoppers due to thermal expansion of wine may result following exposure to temperatures which are significantly greater than ambient temperature. Such physical damage does not necessarily imply that the quality of the wine has also been affected, but it will obviously affect the appearance, and therefore the marketability, of the wine. Humidity is important too, as wines under natural closures can dry out and leakage can occur if the air is too dry; however, in most storage facilities humidity is not adjusted.
A summary of the thermal expansion data for wine, which can be used to predict changes in the volume of wine at various temperatures during storage, as well as to calculate the headspace/ullage volumes required during bottling is provided in the technical note: Thermal expansion data for wine.
Exposure to light during wine storage will also have an impact on wine quality. Light exposure can affect the taste of a wine through the production of volatile sulfur compounds, known as ‘lightstruck’ flavour. This technical note provides a brief summary of the effects of both heat and light on wine storage, including recommendations for ideal storage temperatures: The effects of heat and light on wine during storage. Further information on lightstruck character can be found in this Ask the AWRI article.
Damage during transport – measuring heat related exposure/damage and associated impacts
Wines today are transported all over the world and unless they are transported in a refrigerated container, it is relatively likely that they will be subjected to variations in temperature during transport. Robert Parker (2008) suggests in his wine buyers guide that somewhere between 10 and 25% of wines sold in the USA have been damaged due to exposure to extreme heat. The AWRI’s helpdesk has been involved in many investigations where wines have been exposed to ‘heat’ in transit, as well as investigating wines that have been super chilled or even frozen during transport.
Identifying and demonstrating that a wine has been damaged by exposure to temperature extremes during storage and/or transport can be difficult and results will depend mostly on the degree of damage and the age of the wine. If the wine that is alleged to have been damaged can be compared to samples of the same wine that have not been exposed to extreme conditions (e.g. stock held back or stock not exported and held at constant temperature) there is a much greater chance of being able to understand and demonstrate the extent and nature of the damage . Exporters are therefore advised to retain holdback samples and store them under known conditions so they can be used for comparison in the case of a problem.
Current methods for assessing whether a wine has experienced heat damage include a combination of chemical, physical and sensory tests. Visual assessments are made to look for signs of leakage, closure damage, wine travel or seepage on corks, increased ullage and label damage. Chemical analysis for white wines includes colour development (yellow/brown colour measured by OD420) and free and total SO2 levels (SO2 levels are compared to levels at bottling and losses are compared to closure trial data, which provides an indication of the expected rate of SO2 loss under ideal conditions). For red wines, chemical analysis includes spectral measurements for colour and phenolics and well as free and total SO2 levels. Typically, sensory analysis involves assessment of two dozen of the damaged stock compared to two dozen of the same wine not exposed to the extreme conditions. Wines exposed to extreme temperatures tend to lose their fresh fruity characters and show more developed fruit characters. At extreme levels of temperature exposure, oxidised and cooked characteristics can be observed.
References and further reading
Amon, J.M.; Simpson, R.F. 1986. Wine corks: a review of the incidence of cork related problems and the means for their avoidance. Aust. Grapegrower Winemaker (268): 63–80.
Coulter, A. 2018. Ask the AWRI: Lightstruck character. Aust. N.Z. Grapegrower Winemaker (654): 76-77.
Cowey, G. 2013. AWRI workshop wraps up packaging problems. Aust. N.Z. Grapegrower Winemaker (588): 71-72.
Hirlam, K.C., Scrimgeour, N., Wilkes, E.N. 2019a. Orientation and temperature cycling impacts on the oxygen transmission rate of wine closures. Poster presented at the 17th Australian Wine Industry Technical Conference, July 2019. Available from: https://awitc.com.au/wp-content/uploads/2019/07/3_Hirlam_OTR-Diurnal-Cycling.pdf
Hirlam, K., Scrimgeour, N., Wilkes, E. 2019b. The impact of temperature fluctuations on closure performance. Aust. N.Z. Grapegrower Winemaker (671): 59-61.
Holdstock, M. 2015. Ask the AWRI: trouble-free packaging. Aust. N.Z. Grapegrower Winemaker (617): p. 92.
Information pack – oxygen exposure during winemaking and packing. This is a collection of research articles on the effects of oxygen on wine, both during winemaking and after packaging. Articles can be ordered via this page from the AWRI Library.
Marais, J. 1986. Effect of storage time and temperature on the volatile composition and quality of South African Vitis vinifera L. cv. Colombar wines Charalambous, G. The shelf life of foods and beverages: proceedings of the 4th international flavor conference; Rhodes, Greece; 23-26 July 1985. 169-185: 1986.
Mas, A., Puig, J., Llado, N. and Zamora, F. 2002 Sealing and storage position effects on wine evolution. J. Food Sci. 67: 1374-1378.
Ough, C.S. 1985. Some effects of temperature and SO2 on wine during simulated transport and storage. Am. J. Enol. Vitic. 36: 18–22.
Ough, C.S. 1992. Winemaking basics. Binghamton, N.Y.: The Haworth Press, Inc.: p 242.
Parker, R. M. 2008. Parker’s Wine Buyer’s Guide: The complete, easy-to-use reference on recent vintages, prices, and ratings for more than 8,000 wines from all the major wine regions. Simon and Schuster.
Skouroumounis, G.K., Kwiatkowski, M.J. Francis, I.L., Oakey, H., Capone, D.L., Peng, Z., Duncan, B.,Sefton, M.A., Waters, E.J. 2005. The impact of closure type and storage conditions on the composition, colour and flavour properties of a Riesling and a wooded Chardonnay wine during five years’ storage. Aust. J. Grape Wine Res. 11: 355–368 .
Tran, T., Wilkes, E., Johnson, D. 2015. Microbiological stability of wine packaging in Australia and New Zealand. Wine Vitic. J. 30 (2), 46-49.