Volatile acidity (GARCIA-TENA)

1. The Volatimeter unit is turned on and cold water is circulated through the coolant. The light on the switch lights up to indicate that the appliance is on.

2. Place the 5.1 ml measuring cylinder under the coolant.

3. Measure 11 ml of the wine sample and pour into the distillation flask together with 1-2 granules of silicone pumice.

4. Place the flask on the round joint from the double bend holding it with the metal clamp and rotate until it is placed on the heater, previously heated

5. After a few moments the boiling begins and when 5.1 ml have been collected in the cylinder (#1) it is removed and then the 3.2 ml cylinder (#2) is placed, without losing any single drop. In the case of using a Tenamátic GAB, the change of cylinders are carried out automatically without the attention of the user.

6. Once the distillation is finished, first remove the cylinder and then the flask, taking it by the clamp and turning it forward. The blue clip must not be touched. If other analysis are to be carried out, the Volatometer will not be disconnected so that the heater remains hot.

7. The distillate from the 3.2 ml cylinder is transferred to a 100 ml erlenmeyer flask to which a few drops of phenolphthalein solution are added and it is titrated with N/49 Sodium Hydroxide until a persistent pink color.

8. For a more perfect titration, a portion of the liquid is poured from the Erlenmeyer flask into the 3.2 ml cylinder and returned to the erlenmeyer flask. If there has been discoloration add a few more drops of reagent. record the milliliters spent (N).

9. Multiply the N milliliters spent in the burette by the factor 0.366, thus obtaining the Real Volatile Acidity expressed in grams per liter of Acetic acid.

N x 0.366 = g / l Ac. acetic.