pH IN WINE
by Professor Hrayr Berberoglu.

2004


Many modern style wines sport back labels providing in-depth information about grape variety(ies) in the blend, alcohol content, TA (titratable acidity), pH, harvest date, taste description etc. Most people understand all except maybe the pH which appears at first confusing. It is an important component and warrants wider understanding of its nature and function in wine making. Wine enthusiasts will be able to better assess their beloved drink. pH is a close relative of acidity, specifically the total titratable acidity, and also measures the concentration . It measures the relative strength of acids in wines and is a function of the pH of must, which in turn depends on grape variety, soil composition, and viticultural practices.

Soils rich in potassium yield fruit with high pH. Similarly, grapes harvested during heavy rainfalls result in high pH musts.

A wine with lower pH is darker, more stable during aging, possesses more fruit but less complexity and body than a high pH product. Low pH wines mature slower, and are less prone to spoilage. Acid-containing solutions are measured on a scale of 0 to 14. The middle of the scale is neutral. The lower pH there is, the more acid the liquid contains. In wines, the acidity ranges approximately 3 - 4, thus fractions make a big difference in both the appearance and taste. The pH is closely related to TA and both are interdependent. A low pH wine tastes tart; on the other hand a high pH wine oxidizes faster and fails to mature well.

Free sulphur dioxide protects the wine from oxidation and other types of spoilage. Most, if not all wines contain SO2, some more than others. Some consumers are very sensitive to SO2; some are even allergic. Molecular SO2 is the active component of free SO2 and its effectiveness depends on the level of pH in the wine.

 
Winemakers routinely measure and adjust both TA and pH by:
·	Adding tartaric acid to raise TA and lower pH
·	Blending low and high pH wines to achieve a balance
·	Adding potassium bicarbonate to remove some acidity and increase pH
·	Induce ML (malolactic fermentation) to raise pH
·	Cold stabilization to reduce acidity and increase pH
·	Adding water to lower acidity and increase pH
All of the above would be of little interest to a wine enthusiast, but having some knowledge of chemistry allows one to evaluate and taste wine better. Such knowledge will also enable a wine enthusiast or sommelier to make better buying decisions.

At lower pH, red wines have a brighter colour. They are fruitier, younger tasting for their age, slower to mature, less complex, and slower to spoil. Higher pH red wines are brownish to brown, taste less fresh, show less fruit, tend to be complex, age faster, spoil easier, and possess a fuller body.

This is why the term "balanced" as a wine descriptor means so much to a knowledgeable interlocutor.

pH values in styles of wine 

Style of wine        pH range of must and wine
Dry white            3.1 to 3.4
Dry red              3.3 to 3.6
Sweet white          3.1 to 3.2
Hrayr Berberoglu took early retirement after lecturing on restaurant management and conducting wine, beer and spirits seminars for over a quarter of a century.

Now he consults and writes to increase wine, beer and liquor awareness. He conducts seminars and would be pleased to consider your requests. To peruse the list of his published books and order please contact him at hirayrberberoglu_3@sympatico.ca

Hryar Berberoglu www.littlefatwino.com