Using an eyedropper, put 10 drops of the wine sample in a small test tube and then drop in one tablet. The tablet and wine sample will cause a “boiling” reaction and color change. Carefully observe the color change during the reaction, making sure not to shake the test tube during this time or for 15 seconds after the boiling effect has stopped.
If the color changes rapidly from bright orange to a dark or greenish brown, then the wine sample contains more than one percent residual sugar and a second test with a diluted wine sample is required. Otherwise, after the 15-second waiting period, gently shake the test tube and compare the color of the sample to the color chart to determine the corresponding sugar concentration measurement.
This procedure, from Pambianchi's column in WineMaker magazine, can be easily misleading. I asked WineMaker to publish a correction but they haven't.
The problem is that you aren't told how to get from the observed color change to the sugar reading. The Clinitest Kit comes with two color charts: one for use with a 5-drop method and the other for use with a 2-drop method. But this procedure calls for
10 drops. What do you do?
The answer, provided by Fallbright, Vinquiry, and others is to use the color chart for the 2-drop method but divide the obtained value by 5. For example, the color Dark Brown (5th from left) is 2% on the 2-drop color chart. If you get that color with 10 drops, divide 2% by 5 to get an actual sugar reading of 0.4%.
The 10-drop method is for wines with less than 1% RS. A conversion chart, along with instructions for wines from 1% - 5% and for wines over 5%, was available last I checked from Fallbright, 10110 Hyatt Hill Rd., Dundee, NY 14837.