Glass offers wine some protection from ultraviolet light that can affect wine quality. The correct choice of glass colour and modifications to glass composition or glass coatings can further enhance the protection of the wine. This report has been prepared as part of the WRAP-funded GlassRite suite of projects which are intended to reduce the volume of packaging entering the UK waste stream. The GlassRite projects aim to encourage the lightweighting of glass containers as a means of reducing the tonnage of glass in the waste stream. The GlassRite Wine project has the additional objectives of seeking to promote the bulk importation of wine into the UK to be filled in lightweighted bottles and also to encourage importers of bottled wine to consider the use of clear glass. Filling wine in clear and/or lighter, thinner bottles has implications for its quality, as the bottle will offer less protection to the detrimental effects of light and this could be perceived as a barrier to the adoption of lighter or clear bottles for use in the wine trade. This report seeks to address this barrier by presenting information relating to the effects of light on wine and the changes that can be made to glass compositions to modify optical properties. Whilst the report is able to offer precise information on the critical wavelengths that affect wine and the filtering abilities of various glasses, it is limited in its practical interpretation by the considerable variation in light exposure experienced between different products. By necessity the GlassRite Wine project is focused on the high volume, entry-level market for wine, much of which spends most of its life boxed in cardboard packaging seeing little light until it is unpacked and displayed on the retailers shelves. The report thus informs on technical opportunities but requires interpretation as to the applicability to any given product.
