MONITORING THE GRAPES
Every quality product starts out life as raw materials. For that reason the Laboratory has developed a package of analyses for investigating the health and ripening of the grapes before the vinification process has started, checking the sugars present, the acidity (total acidity, PH, tartaric acid and malic acid), the availability of nitrogenous components (APA) and, in the case of the red grapes, the degree of phenolic maturation (total polyphenols and anthocyanins).
Quality control continues with scrupulous examination of the fermentation process, monitoring its development and if necessary intervening at any critical moments that might arise. Here, too, the measurement of the acidity figures (total acidity, pH, tartaric acid and malic acid) is essential, and in particular the value of volatile acidity. The overall content is examined (including degrees of alcohol, total sugars, glucose and fructose), the APA as above and in the case of the red musts, total polyphenols and anthocyanins.
Also at the end of the process, product control is a matter of vital importance. In addition to all of the above measurements it is important at this point to look closely at metabisulphite content (total, free and molecular sulphur) and metal content to avoid unpleasant vat-related spoilage problems from copper and iron and to check also for protein stability, especially in the white wines. The laboratory has also developed analyses that measure correct bentonite quantities.
Once the product has been vinified it is essential to check that the wine is in a condition for going to bottling such that it will not affect its qualities, both at the piìoint of bottling itself and at the moment it is placed on the market. The laboratory offers control packages to ensure the wine’s stability and its best possible quality.
The laboratory has developed two methods for calculating the wine’s tartaric acid stability:
Traditional controls are carried out with regard to five key factors, that is to say the degree, total acidity, PH and the potassium and tartaric acid contents. Together these define the solubility of the principal cause of tartaric precipitation (i.e. potassium tartrate) and establish the current and ideal saturation temperatures.
For over a yaear now a new laboratory tool has been added to this methodology, that of the Criocheck. This is a new frontier for the calculation of wine stability. As well as calculating the correct saturation temperature, it exploits the drop in conductivity resulting from the addition of metatartaric to a sample so as to draw a saturation curve that can be used to study the stability or otherwise of the product. More lifelike tests are then carried out directly on the analysed sample, taking into account all factors that contribute to and affect stability.
MONITORING AFTER BOTTLING
Despite all the care that the wine producer puts into the making their product, once in the bottle there are still things that can go wrong. The Laboratory is equipped to seek out all possible problems, with tests ranging from microbiological analysis to the microscopic analysis of any sediment.
In addition to wine, the Laboratory is able to provide its services for other agricultural products:
Oleic Acidity: Measurement of free fatty acids, which is key to determining the quality of an olive oil (being extra virgin where less than 0.8%)
Peroxide number: The main defects encountered are associated with unpleasant smells that can significantly depreciate olive oils, for which there is now in place a body of law that sets forth all the required organoleptic characteristics of the product. When it comes to degradation of the product the principle offender is oxidative rancidity or self-oxidation. This is largely a chemically produced rancidity that attacks the unsaturated fatty acids, both free and glycerol-linked. This method measures the primary products of the self-oxidation process by means of iodometric titration.
Spectrophotometric Analysis: Measurement of K232, K270 and ΔK parameters to identify any changes in the quality of the oil.
Measurement of the degree of alcohol and the copper and methanol content
BEER AND LIQUEURS
Measurement of degrees of alcohol