Closure Performance
The AWRI ( Australian Wine Research Institute) was engaged to technically evaluate the SPS screw cap closure performance, over 18 months, bottled with a tank fermented NV Pinot Noir/Chardonnay Cuvee sparkling wine, using Amorim twin-disc natural cork as a bench mark.
Results conclusively supports the impressive SPS closure
reduced Sulfur Dioxide - reflects a health benefit
OTR - reduced wine oxidation
Co2 retention - increased shelf life
Comparison
The wine bottled under the SPS screw cap was significantly higher in toast aroma and bubble concentration on the palate whereas the wine bottled under cork was significantly higher in rose gold tinge. There was a trend that the wine bottled under screw cap was rated slightly higher in bead vibrancy, overall aroma intensity, bruised apple, butter and nutty aroma and lower in floral aroma to the wine bottled under cork, although none of these differences were statistically significant.
CO2
The dissolved Co2 concentrations for the sparkling wine under the two closures are presented below in Figure 5. The Co2 levels under the SPS screw-cap were significantly higher during storage after 18 months in bottle than under the natural cork closure. The dissolved oxygen concentrations in the wine under cork decreased and then remained relatively consistent at around 0.2mg/L, while the concentration under the SPS closure decreased below 0.1mg/L, which is the limit of detection for the analytical method
Oxygen Transmission Rate
The SPS closure, when used with the modified O-I bottle, showed very consistent OTR values that are relatively low with respect to data typically observed for other standard sparkling wine closures. Although the values below were measured on a ‘wet’-basis, i.e. with wine in the bottle, there is typically little difference between OTR values measured in this manner and those measured on a ‘dry’-basis (i.e. with no wine in bottle), as with the case with the SPS closure here.
Free and Total SO2