Also known simply as alcohol, or grain alcohol, ethanol is the primary alcohol found in wine. Ethanol is a critical constituent of wine and is produced from sugar during fermentation. The concentration of ethanol in wine can affect taste, microbial activity, the solubility of compounds, and tax rates.
Residual Sugar (RS)
Glucose and fructose are natural compounds produced by vines during photosynthesis. In wine, Glucose + Fructose is often synonymous with “Residual Sugar”, measured near or after the end of primary fermentation to evaluate dryness.
Free Sulfur Dioxide (SO2)
Free sulfur dioxide is a measure of the amount of SO2 that is not bound to other molecules, and is used to calculate molecular SO2. Sulfur Dioxide is usually used throughout all stages of the conventional winemaking process to prevent oxidation and microbial growth. Excessive amounts of SO2 can inhibit fermentation and cause undesirable sensory effects.
Total Sulfur Dioxide (SO2)
Total sulfur dioxide (SO2) is a measure of both the free and bound forms of SO2. Bound SO2 refers to SO2 molecules that are bonded to other compounds, primarily aldehydes, pyruvate, and anthocyanins. Sulfur Dioxide is usually used throughout all stages of the conventional winemaking process to prevent oxidation and microbial growth. Excessive amounts of SO2 can inhibit fermentation and cause undesirable sensory effects.
pH is the measure of a solution’s acidity, or hydrogen ion concentration. Solutions with low pH values (<7) are acidic, while those with high pH values (>7) are basic. Wine pH values typically fall between 3.0 and 4.0 on the pH scale. However, pH is measured on a logarithmic scale, so a wine with a pH of 3.0 is 10 times more acidic than a wine with a pH of 4.0. pH is a critical constituent of wine, affecting microbial activity, tartrate solubility, the interaction of phenolic compounds, and molecular SO2levels.
Titratable Acidity (TA)
Titratable acidity (TA) measures total available hydrogen ions in solution. This measurement includes both the free hydrogen ions and the undissociated hydrogen ions from acids that can be neutralized by sodium hydroxide. Although generally considered a simple parameter, titratable acidity is actually a reflection of complex interactions between the hydrogen ions, organic acids, organic acid-salts, and cations in solution. Results of this test are reported in terms of Sulfuric Acid, which is the standard reporting convention for TA in the European Union.