Understanding the wine data columns

The data-set is related to white variants of wine

1. fixed acidity : most acids involved with wine or fixed or nonvolatile (do not evaporate readily)

2. volatile acidity_ : the amount of acetic acid in wine, which at too high of levels can lead to an unpleasant, vinegar taste

3. citric acid : found in small quantities, citric acid can add ‘freshness’ and flavor to wines

4. residual sugar : the amount of sugar remaining after fermentation stops, it’s rare to find wines with less than 1 gm/liter and wines with greater than 45 grams/liter are considered sweet

5. free sulfur dioxide : the free form of SO2 exists in equilibrium between molecular SO2 (as a dissolved gas) and bisul-fite ion; it prevents microbial growth and the oxidation of wine

6. total sulfur dioxide : amount of free and bound forms of S02; in low concentrations, SO2 is mostly undetectable in wine, but at free SO2 concentrations over 50 ppm, SO2 becomes evident in the nose and taste of wine

7. density : the density of water is close to that of water depending on the percent alcohol and sugar content

8. pH : describes how acidic or basic a wine is on a scale from 0 (very acidic) to 14 (very basic); most wines are between 3–4 on the pH scale

9. sulphates : a wine additive which can contribute to sulfur dioxide gas (S02) levels, which acts as an antimicrobial and antioxidant