Monday, March 23, 2009

Using an Acid Test Kit to Measure Wine Acidity

A simple and inexpensive way to measure the acidity level (TA) is to purchase a home wine making acid test kit from the BlueStem Winery web site. This acid testing kit uses a titration method to determine the acid level present. Without teaching a lesson in high school chemistry, titration testing involves the addition of a reagent (in this case it is sodium hydroxide) to a mix of your wine and a color indicator (phenolphtalein).

A wine sample (15ml) is drawn and placed in a test tube. Three drops of the color indicator are drawn and added to the wine sample. Swirl the test tube until the wine and indicator are thoroughly mixed.

Next a syringe is used to draw 10ml of the reagent. The reagent is added to the test tube containing the wine/color indicator at the rate of 0.5ml. After each addition the test tube is swirled to mix the reagent with the wine/color indicator. As the drops are added the color of the mix in the test tube will change. White wines will turn pink, red wines will turn gray/black. As the test tube is swirled the color change disappears. Keep adding the 0.5ml droplets until, when swirled, the wine/indicator mix does not go back to its original color. Each milliliter of reagent used indicates an acidity level of 0.1% TA. Correct acidity levels for various types of wines was presented in my just prior blog entry.

BlueStem Winery is a wine making and homebrew supply retailer located in Parkersburg, Iowa and on the web. BlueStem features a comple line of beer brewing and wine making equipment plus an excellent assortment of our own BlueStems Best home brewing ingredient kits and an extensive inventory of both Cellar Craft and WinExpert wine kits. You can expect that you will not be treated like a purchaser at a big box home brew equipment retailer. We offer beer ingredients, brewing equipment and beer brewing kits at reasonable prices but our time and advice provided in any quantity free of charge. We take the time to see you through any winemaking or homebrew problem.

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