How to Test for Tartaric Acid

If you are a winemaker, and you want to produce a wine that has the right level of acidity—so it has a longer shelf life—you need to know how to test for tartaric acid. Knowing this important procedure will help you to add just the right amount of sodium hydroxide during your wine-making process.

Tartaric Acid

Tartaric acid comes from plants (and from the juice of grapes) and is used in many processes (food and medications), as well as wine making. In fact, it is a critical component in the wine-making process. And according to Wine Perspective.com, wine that doesn’t have enough tartaric acid is going to produce a flat, dull taste, and wine that has too much in it will taste sour and tart. Hence, the need to test for tartaric acid.

Wine Making and Testing

Testing for tartaric acid is an important step in the wine-making process, and according to More Wine-making.com, the acidity of the wine doesn’t just determine its taste; it also determines if the end product produced will be long-lasting too. Preferred wine acidity levels vary by wine and personal taste, but guidelines are available to assist winemakers with appropriate base concentration levels to work from.

Testing Tools

The tools needed to test for tartaric acid in the wine-making process include a 12 mL plastic syringe, a reaction vial with cap, some distilled water, a 4-ounce bottle of 0.1N sodium hydroxide (NaOH), and a phenolphthalein indicator in a glass bottle with a dropper. In addition, a portion of the wine to be tested is also needed.

Testing Procedure

Draw 5 mL of the wine with the plastic syringe and put this amount into the reaction vial. Add enough distilled water to the vial to bring the liquid level up to two-thirds full. Now, add three drops of phenolphthalein. After cleaning the syringe (and drying it thoroughly), use it to draw 10 mL of sodium hydroxide, but add only 0.5mL of it to the vial at a time, capping the vial and shaking it well before uncapping and repeating the process.