Aim of this project

To find out which chemical properties influence the quality of red wines using the given dataset wineQualityReds.csv.

Overview of the given dataset

The given dataset contains 1,599 red wines with 11 variables on the chemical properties of wine. Atleast 3 wine experts rated the quality of each wine, providing a rating between 0 (very bad) and 10 (very excellent).

Attribute information:

Input variables (based on physicochemical tests):

1 - fixed acidity (tartaric acid - g/dm^3)

2 - volatile acidity (acetic acid - g/dm^3)

3 - citric acid (g/dm^3)

4 - residual sugar (g/dm^3)

5 - chlorides (sodium chloride - (g/dm^3)

6 - free sulfur dioxide (mg / dm^3)

7 - total sulfur dioxide (mg / dm^3)

8 - density (g/cm^3)

9 - pH

10 - sulphates (potassium sulphate - (g/dm3^)

11 - alcohol (% by volume)

Output variable (based on sensory data):

12 - quality (score between 0 and 10)

13 - Missing Attribute Values: None

Description of attributes:

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 gram/liter and wines with greater than 45 grams/liter are considered sweet

5 - chlorides: the amount of salt in the wine

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

7 - 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

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

9 - 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

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

11 - alcohol: the percent alcohol content of the wine

Output variable (based on sensory data): 12 - quality (score between 0 and 10)

References

1. Udacity forum
2. IMPORTANCE OF PH IN WINE MAKING
3. Linear regression algorithm | Edureka
4. ggplot2 graphs reference
5. R Graphics Codebook by Winston Chang