The science of enology continues to study the topic of wine stabilization. Essentially, the goal is to avoid the precipitation of wine crystals consisting of potassium bitartrate (potassium hydrogen tartrate) or calcium tartrate in the bottle. Wine-drinkers are still averse to the presence of sediments in the wine glass (Fig. 1).
In the years 2018 and 2020, the following vinification variants were tested with respect to their stabilization properties (using 2017 and a 2019 Sauvignon Blanc):
Control without stabilization measures (C),
Cold stabilization (CS) at -4 °C for 2 weeks,
Metatartaric acid (MTA) 10 g/hl (only 2018 for 2017
Sauvignon Blanc),
Carboxymethylcellulose (CMC) 10 g/hl
Potassium polyaspartate (PPA) 100 ml/hl and 50 ml/hl.
The study was performed three times, with a size of about 10 L per sample.
The electrical conductivity (µS) of the wine was taken as a measure of the bitartrate stability; this was measured shortly after bottling and after 7, 14, and 21 weeks (Fig. 2) as well as after 52 weeks (Fig. 3). The Checkstab α2000 Life measuring device was used for these measurements. This device measures the change in conductivity (ΔµS) caused by unstable potassium bitartrate crystals, and thus simulates bitartrate stability. Stability is said to be present if the decline in conductivity is less than 40 µS. A drop in conductivity in the range of 40-60 µS is classified as uncertain stability, while a decrease of more than 60 µS indicates that the product is unstable.
The wines also underwent sensory testing. During the tasting, the following parameters were evaluated: Color, turbidity, purity, intensity, fruitiness, bitterness, typicity, developmental stage, and overall impression.
