The Importance of pH in Winemaking

Acidity In Wine-Making

Wine acid refers to the acid levels that determine their taste. The acidity of wine includes malic acid, tartar, and citric acid. This acid causes a sour taste in wine and helps maintain its crispness and flavor balance.

Understanding pH

Many winemakers talk about pH and acidity when they discuss wine quality. There are two ways to measure how acidic a wine is: pH and total acidity (TA).

• pH measures the concentration of free hydrogen ions in the wine. It tells if a solution is acidic or basic, measured on a scale from 0 to 14, with 7 being neutral. Most wines have a pH range between 2.8 and 4. The closer the pH is to 3, the better it is for the wine’s stability and taste.
• Total Acidity (TA) measures the total amount of hydrogen ions in the wine, expressed in grams per liter.

Understanding pH and TA is important because they affect the wine’s stability and sensory properties.

The Effects Of pH On Wine Quality

How does pH affect the taste of wine?

In wines, pH is key for longevity, meaning that the higher the pH is, the less stable the wine will be.  For example, red wines are less protected against oxidationWhat is the best way to aerate red wine ... at higher pH levels, the concentration of flavanols increases, and the concentration of anthocyaninsWhat role do Anthocyanins play in wine? ... More decreases. This means bitterness, astringency, oxidation, microbiological risks, and less chemical stability, for example, in the equilibrium with sulfur dioxide, color stability, and effectiveness of bentonite.

As noted previously, pH in wines can influence their overall quality, from their aroma and flavor to their durability and shelf life. By carefully monitoring pH levels throughout the wine-making cycle, winemakers can correctly balance acidity and alkalinity, resulting in delicious and long-lasting wines!

How to Accurately Measure pH in Winemaking

Winemakers use several techniques to measure the pH of wines. One standard method is titration, where a wine is combined with a known amount of alcohol until it neutralizes the acidity. To determine the acidity, the wine must require an adequate solution.

Another way to measure pH is with a pH meter. It’s essential to calibrate the pH meter before using it and to keep it on a stable, clean, and dry table. This is usually done using 4 and 7 pH buffers.

Additionally, winemakers may use wine acid testing kits, which include all the necessary equipment and instructions to measure wine acid. However, a pH meter is the most accurate way to assess the wine’s pH.

My Advice for You

When you buy 1-liter buffer solutions, pour some into small plastic containers. If you suspect contamination, just throw away the liquid in the container, not the whole solution.

• Always keep the electrode clean and inside its specific liquid. If the electrode dries out, you must buy a new one.

• A common mistake is switching between must and wine samples without adequately cleaning the electrode. This will give you incorrect data.

• Temperature is also critical. Adjust the calibration temperature to match your wine’s or must sample temperature. For example, if you calibrate the pH meter at 20ºC (68ºF) and your sample is at 10ºC (50ºF), your results will be wrong.

How Does pH Change Throughout The Winemaking Process?

As grapes ripen, their acid levels decrease, and the pH increases. Too-ripe grapes will have almost no acidity, which is a big challenge in warm weather.

A good winemaker checks the pH levels when sampling grapes before harvest. They also consider sugar, tanninsTannins in Wine Tannins in wine are phen... More, and titratable acidity. These factors change as the grapes ripen and are important for deciding the best time to harvest.

what is the best Ph for Winemaking?

Understanding pH Levels in Wine

The recommended pH ranges vary depending on the type of wine you are making:

• Sweet wines: Less than 3.4
• Red wines: Less than 3.4
• White wines: Less than 3.3
• Sparkling wines: Around 3.2

Keeping the proper pH levels is essential because most bacteria and fungi can’t grow at lower pH levels (3 – 3.6). This helps protect the wine from spoilage.

For example, if the pH levels are closer to 3, malolactic bacteria can’t survive. This is good for making fresh, crisp, young white wines but not for red wines that need malolactic fermentation. That’s why a pH range of 3.4 is suitable for red wines.

Throughout the fermentation phases of wine, the pH changes dramatically. The wine begins at the grape itself. During the alcoholic fermentation, the yeast Saccharomyces cerevisia produces ethanol and several other acids. Among the examples are succinic acid and acids.

What is too low pH for wine must?

A lower-pH wine tastes bitter due to higher acid concentrations. Conversely, a high pH wine may be bland and lack freshness. But remember, pH in wine is the most important factor as it significantly affects bacterial stability and spoilage risk, whereas higher pH micro organisms grow.

What is the pH of fresh wine?

Typical for wines with 3.2 – 3.6 pH ranges will fit. It seems certain wines taste better in one part of the line and in another. White wines are generally more acidic than red wines.

pH corrections 

 It is a key factor to adjust pH as early as possible before the fermentation process begins. pH levels should be adjusted even before the inoculation of yeasts. 

There are different methods to alter pH, depending on what you need. One method may be to blend musts with lower pH levels. Perform trials on small samples before treating the whole tank. This way, you make sure to achieve the desired results. 

The other method, and more common, is a chemical process.

If you have higher pH levels, you will need to add tartaric acid to the wine to lower it. However, adding too much acid can cause small crystals of potassium hydrogen tartrate (KHT) to form in the wine tank or bottle, and it will also decrease the total acidity (TA). Keep in mind that pH will increase during fermentation due to the potassium ions in the grape skins.

If pH levels are increasing, the process is called deacidification. In this case, you can add calcium carbonate or potassium bicarbonate, but only for very small adjustments. The salt produced can be removed during filtration. Another option is to perform a malolactic fermentation, which converts malic acid into lactic acid and increases the pH. This secondary fermentation helps to precipitate tartaric acid.

Advantages that come with maintaining a low pH value in wine

• Stop bacteria from growing

• Balanced alcoholic fermentation

• Control over malolactic fermentation

• Protein stability (even at warm temperatures)

• Effective use of bentonites

• Color intensity

• Lower oxidation risks

• Effective SO2 readings and additions

• Better aging process
  

  

The Last Pour

Several factors like grape variety, climate, soil, ripeness, fermentation, and aging will affect acidity and pH levels. Having the right pH levels in your wine will result in the best aroma, flavor, color, mouthfeel, and longer shelf life. Finding the equilibrium depending on the wine you are producing is easier with healthier and high-quality grapes. Do not hesitate to keep up the good work in the vineyard, and all that hard work will result in a great wine.