For a long time I have wished for something better than natural corks to protect the wines I made. The problems with natural cork are twofold. The first and worst is that at least 1-2% are tainted with mold flavors which gets into the wine. The second is that the porosity of corks to oxygen is variable over a three fold range, so the individual bottles of wine age at a random and unpredictable rate. For most of my thirty years as a winemaker there has been no viable alternative to natural cork. However, a few years ago a French company made some crucial improvements to an earlier product that made for a real improvement over natural corks without sacrificing any of the many good things that have made corks the standard choice for a few hundred years. The product is called DIAM and it is made by grinding up cork, stripping all of the aromas out of it and then molding it back together with polyurethane. This type of cork, (which is termed) "agglomerated," has been used for some time. All Champagne corks use this technology. The two things that make DIAM superior are that the cork has been neutralized flavor wise and that the plastic binding material has been designed to breathe slightly so that the tiniest amount of oxygen flows through the cork and helps the wine age. With this said, Tolosa Winery has now made the decision, which seems so clear to protect our product, that all vintages beginning in 2008 will be with a DIAM cork, except for our screwcap closures.
For those who would like a visual, here are the two different corks, click on pictures to see details.