Issue link: http://winesandvines.uberflip.com/i/116287
g WINE g rAoKw i n g rape M ING A. Electrodialysis — removal of potassium and bitartrate ions through separation methods. This process uses charge and membrane technology to selectively remove potassium and bitartrate ions (with a relatively minor loss of related species). This method directly lowers the available ions for salt crystal development. B. Ion exchange — cation exchange (sodium or hydrogen ion exchanges for potassium and other wine cations), anion exchange (organic anions or hydroxide for tartrate ions) or a combination of anion and cation exchange. Ion exchange reduces the concentration of the potassium, calcium and/or tartrate ions. Cation or anion exchange may be receiving renewed interest due to recent commercial enhancements in the size of ion exchangers and in the cost of resins available. Cellar Treatment Category III: Ionic species complexing and crystal fouling methods A relatively new option for stabilizing wines, these methods do not reduce the actual concentrations of the potassium (or calcium) and tartrates. They reduce their effective concentration through chemical complexing and increased crystal fouling. Because these colloidal complexes are fragile, many wine processes, such as chilling or warming, filtration, fining, mixing or oxidation could disturb these complexes. A. Increased yeast lees contact time — maximizes natural (in situ) man- noprotein extraction/concentration. Originally applied to sparkling wines, and then observed in wines with extended sur lies aging, the increased lees contact resulted in increased in ionic complexing and crystal fouling. B. Addition of commercially available/ approved colloidal materials — includ- ing mannoproteins, carboxymethylcelluloses or acacia gums (or meta-tartaric acid in countries that allow its use). These macromolecules act on several levels. They may interact with the ionic species to effectively decrease their apparent concentration, or may impede the formation of the nuclei, or may impede integration of the ions onto the crystals through steric hindrance by association with the ions, or may "foul" the crystals. Commercial application of complexing agents require strict adherence to manufacturer's recommendations, as these are rarely "simple" additions and entail planning, proper sequences and atten- EXPORTING WINE? CERTIFICATES OF ANALYSIS Exporting wine is complex and confusing... Allow us to make the process less painful... ETS Laboratories is internationally recognized as a qualified third-party provider of analytical certificates which meet the many and varied requirements of different countries and individual importers. Our staff is up to date on analytical requirements worldwide, and our ISO 17025 accreditation and TTB certifications ensure international acceptance of your certificates. ...GO GLOBAL export@etslabs.com www.etslabs.com | info@etslabs.com | 707 963•4806 St. Helena CA | Healdsburg CA | McMinnville OR | Roseburg OR | Walla Walla WA 58 p r acti c al w i ne ry & v i ne yard APRIL 20 13 tion to temperature, filtration status and other wine treatments for best effect. Laboratory testing methods to confirm cold stability of wine All tests for cold stability are a "predictive index" and should be approached with an understanding of what they are predicting and how the test relates to the actual wine/situation/expectation relationship. Some of these methods attempt to predict if a wine will not precipitate crystals under any condition; others try to forecast for specific circumstances; while others methods limit their predictive modeling to the actual conditions of the lab test. The current range and assortment of laboratory testing methods and indexes can be categorized into chill methods, conductivity methods and solubility methods, with variations within each type. Lab Testing Category I: Chill methods These relatively simple tests use a drop in temperature over time as a predictor of a wine's likelihood to precipitate crystals. The nature of these tests makes them a poor index of calcium instability due to the short time and lack of any kinetic enhancers.