Sulphur Dioxide – Free
70mL of sample required (Note: fill sample container to full)
The Sulfur dioxide (SO2) is added to must, juice or wine to aid in the prevention of oxidation and/or spoilage. In conjunction with pH, the optimum Sulfur Dioxide concentration required to protect the wine from bacterial spoilage can be determined.
Sulphur Dioxide – Total
70mL of sample required (Note: fill sample container to full)
The Sulfur dioxide (SO2) is added to must, juice or wine to aid in the prevention of oxidation and/or spoilage. In conjunction with pH, the optimum Sulfur Dioxide concentration required to protect the wine from bacterial spoilage can be determined.
Alcohol
Minimum 500mL of sample required.
Distillation is the recognised reference method for the determination of alcohol content. In Australia it is expressed in terms of per cent by alc/volume (i.e. % Alc/Vol) at 20 oC and is needed to meet legal requirements and for labelling purposes.
pH/Titratable Acidity
70mL of sample required.
The pH test is suitable for juice, wine and other liquids. An important test as it helps determine the molecular SO2 molecular level required to protect your wine. Also has an influence on colour, balance and taste as well as protecting wine from bacterial growth.
The juice and wine is titrated to a pH 8.2 end-point with standard alkaline solution. The result gives an estimate of the acid content of the juice or wine, and is expressed as g/L tartaric acid.
Malic Acid
70mL of sample required.
Malo-lactic fermentation (MLF) occurs in wines when bacteria covert malic acid to lactic acid. The test can be used to measure malic acid levels in wine to assess whether MLF has been completed in a wine. Completion of MLF is considered to be a malic acid level of below 0.03 g/L.
Volatile Acidity
70mL of sample required.
Volatile acids (VA) found in wine include mainly acetic acid. High VA is objectionable and indicates spoilage and incorrect storage of the wine and monitoring is important to detect onset of this spoilage. It is accurately measured enzymatically and concentrations of less than 1.5 g/l are required by compliance.
Glucose and Fructose
70mL of sample required.
There are a number of different sugars in grape juice and wine with glucose and fructose the main sugars. Not all sugar of the reducing sugars are utilised by yeast and therefore small amounts remain at end of ferment. Test results are usually reported as the total of these two parameters and 2 g/l or less indicates completion of fermentation (residual sugar). However, they may also be reported separately in certain circumstances, e.g., investigating sluggish or “stuck” ferments.
Bentonite Fining Trial
750mL of sample required.
Used in conjunction with a heat stability test, a bentonite fining trial can be performed to determine the optimum addition rate.
Note: please supply us with 10 g of the bentonite you intend to use in your winery.
(4 Addition rates will be tested per sample).
Heat Stability
70mL of sample required.
The presence of unstable proteins in a wine can lead to the development of a haze or deposit. It is often associated with denaturation of proteins occurring at higher temperatures. The sample is filtered and heated to 80°C degrees Celsius for 6 Hours and then assessed after cooling for haze development by NTU. Absence of haze indicates a protein stable wine.
Cold Stability
70mL of sample required.
Wine is super saturated with potassium bitartrate (KHT) and when concentrations of K+ and HT- are such that solubility product of KHT is exceeded and crystals form in wine. The sample is subjected to a temperature of -4 degree Celsius for 72 Hours and assessed for formation of crystals.
Turbidity
70ml of sample required.
This is a measure of wine clarity, given in nephelometric turbidity units (NTU). It is used by winemakers to gauge the effectiveness of clarification processes or help determine the extent of pre-bottling filtration required.
Brettanomyces membrane filter culture
750ml of sample required.
For this analysis 100ml of wine is filtered through 0.45 µm membrane and incubated for 10 days with brettanoymces selective medium which prohibits the growth of non-brettanomyces yeast. The plates are assessed at 3, 7 and 10 days. Results are taken at 10 days and are either reported as no growth (pass) or growth (fail). The cfu/mL (colony forming units per mL) we also be reported. Brettanomyces yeast tends to settle, so please ensure barrels are well stirred prior to sampling or sampling from barrels must occur from bottom.