Saturday, July 12, 2008

Acidity in Wine: Part 3

Acidity in wine can be measured easily and inexpensively. Our acid titration kit is part number 03-54000 and can be found in the testing section of the BlueStem Winery website (

Titration is simply the process of determining the concentration of a substance in a liquid. When testing wine for acidity you are trying to determine the acid concentration present in your wine sample. Two chemicals are used in this process. The first is Sodium Hydroxide (NaOH) which is the reagent (base) in this test. The second is Phenolphthalein with is used as the indicator. A small amount of the color indicator (the Phenolphthalein) is added to your wine sample. The reagent (NaOH) is then slowly added to the sample until white wines turn pink/red or until red wines turn blue/grey/black.

Using a plastic syringe (included with the testing kit), measure 15cc of wine or juice into the test bottle (also provided). Add three drops of the Phenolphthalein color solution to the sample.

Draw 10cc of the Sodium Hydroxide into the syringe. Avoid contact with your skin as this solution burns.

Add the Sodium Hydroxide in very small increments to the wine sample. Agitate the sample after each addition. Keep doing this addition until there is a slight color change and it remains after agitation. Continue the small additions (continue to agitate after each addition) until a deep, dark color change is noted and it does not diminish with agitation. This indicates that the end point has been reached.

Each 1cc of the Sodium Hydroxide which was required to get to this point indicates 0.1% of acid (expressed as Tartaric) present. If 5cc of the neutralizer was required the acid level is 0.5%.

You can adjust the acid level upward to the desired level by adding one teaspoon of Acid Blend (per gallon of wine) to raise the acid level by 0.15%.

Dispose of the sample used (do not add this back into your wine).

When making wine at home you should always test for acidity levels prior to starting your fermentation. The exception to this would be if you are using one of our Cellar Craft or WinExpert wine kits as the juice concentrate used in these kits has been balanced as part of the manufacturing process.

BlueStem Winery operates a retail store and a web presence from 305 Third Street in Parkersburg, Iowa. BlueStem specializes in providing high quality wine making equipment, ingredients and supplies plus we carry a complete line of homebrew supplies, home brewing equipment and beer brewing ingredients. BlueStem inventories a large selection of wine making kits and features both WinExpert and Cellar Craft kits. We manufacture our own line of homebrew ingredients kits known as BlueStems Best.

Both our WinExpert kits and our Cellar Craft wine kits provide the home winemaking enthusiast with the very best quality wine concentrate kits available on the market.

No comments: