Reliable Wine Quality Testing Requires Proven Reagents and Equipment
Although, only tasting can really confirm the true character of a wine, less subjective forms of quality testing are a necessary precaution for the commercial producer before he or she may entrust it to the consumer’s palate. Few beverages are more complex than those that are derived by the act of pressing and fermenting the humble grape. In practice, although it is the many unidentified components that result during its preparation which are largely responsible for the uniqueness of a given cultivar and vintage, it is essential to ensure that there are no undesirable or potentially harmful substances present which might threaten to spoil its taste or limit its lifespan.
One of the essential processes that must be routinely employed by the winemaker in pursuit of the perfect vintage is aging. This may be carried out either in barrels or in tanks but, regardless of the vessels used, the status of their contents will need to be checked at fairly frequent intervals using various proven wine quality testing procedures prior to bottling.
The checks that are routinely employed have been designed to determine the levels of a number of key components or properties that are largely common to the overall mix but that are also known to exert a significant influence on the perceived palatability of the finished product. Determining those levels and making any adjustments that are found to be necessary to maintain them within acceptable limits, forms a crucial part of the winemaker’s art and one whose success is as dependent upon the use of reliable test kits as it is on his or her skill and experience.
One of the investigations that have always been performed as part of any regimen of wine quality testing is the so-called Brix test. In practice, it may be applied to any liquid and although it’s intended primarily as a measure of its sugar content, it does, in fact, indicate the total concentration of dissolved solids which, in the case of grape juice, is predominately sugar anyway. The results are derived by extrapolation from the specific gravity of the solution and are expressed in units referred to as degrees Brix (°Bx). One unit on this scale is equivalent to 1 gram of sucrose dissolved in 100 grams of solution or 1% w/w.
This procedure, along with simple pH measurements, are often still be determined by traditional means but a more accurate view of the overall composition is now possible with the help of a compact spectrophotometric analyser. Armed with this versatile device, the winemaker can determine a complete analytical profile of a product in just a 10 minute session of wine quality testing. The results obtained include accurate measurements of the acetic acid, malic acid, lactic acid, total sugar, alcohol total and free sulphur dioxide contents as well as the pH and total acidity.
In the past, such evaluations were far more time-consuming and it needed both an extensive collection of complex apparatus and skilled analysts to conduct them. Armed with these modern analysers, lengthy and costly procedures such as the High Performance Liquid Chromatography (HPLC) once used in the determination of carboxylic acids, sugars glycerol and ethanol can be replaced with this new technology saving the viticulturist both time and money.
A leader in the field of food and beverage diagnostics, CDR Systems has developed a simple-to-use, compact and comprehensive kit specifically for use in wine quality testing. Known appropriately as WineLab it is comprised of a spectrophotometer with multiple incubated cells, a collection of specific reagents in disposable vials and micro-pipettes for accurate measurement of the micro-litre sample volumes together with some smart software that enables the analyser to interface with a personal computer so as to print out reports and store historic test data.
The kit’s exceptional ease of use means that it takes only a few minutes to master its operation and start producing results so it will require no in-depth re-training of staff when introduced. In addition to this product CDR also offers similar kits for analysis of dairy products, edible oils and various processed foods. All of these may be obtained in South Africa from IEPSA. We are a local supplier specialising in the sourcing, sale and distribution of a wide range of equipment and reagents for use in public health, food analysis, for both diagnostic and therapeutic applications within most disciplines of medicine and, of course, the versatile systems for wine quality testing described.
