Have you ever wondered what the technical notes have to do with a wine? You'll often see numbers relating to pH and TA (total acidity) on a sheet of winemaker notes for a given wine. But what does that stuff mean and what does it have to do with the wine?
Good questions. For the non-chemists among us -- and I certainly put myself in that category -- the Wine Spectator has a simple explanation on their site that is a good starting point. Here's what they have to say:
PH is the measure of the degree of relative acidity versus the relative alkalinity of any liquid, on a scale of 0 to 14, with 7 being neutral. Winemakers use pH as a way to measure ripeness in relation to acidity. Low pH wines will taste tart and crisp, while higher pH wines are more susceptible to bacterial growth. Most wine pH's fall around 3 or 4; about 3.0 to 3.4 is desirable for white wines, while about 3.3 to 3.6 is best for reds.
TA, or "total acidity," is another way of looking at similar things, this time measuring acidity by volume. How do they relate? The higher the pH, the lower the acidity, and the lower the pH, the higher the acidity. Most table wines will have a total acidity of about 0.6 to 0.7 percent.
While these numbers might mean something to chemists and wine geeks, it's important to remember that the way a bottled wine tastes is about the relationship of things like pH and TA to other factors like alcohol, tannin, extract and sweetness. There's no chemical formula to make great wine—not yet, anyway.
Acids have a part to play in winemaking and winetasting.
Acids in grapes are most present just before veraison, and since acids decrease as sugar levels rise, wines from cooler climates tend to have a higher acidity than wines from warmer regions. In the winery, acids in the wine play a role in fighting off bacteria and winemakers will sometimes add acid to help with this naturally occurring process.
When tasting a wine, acids help give the wine structure and provide a sharpness and definition to flavors. But a wine that has too much acid will taste sour and sharp, while a wine that has too little acid will taste flat and flabby with less defined flavors.
As in all things when it comes to winemaking --and you could argue, in life as well-- a healthy balance is key