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DETERMINING ALCOHOL % VOL THROUGH DISTILLATION METHOD

Required Material

 

-                   VOLUMETRIC FLASK  250 ML W/ STOPPER

-                   SPHERICAL FLASK W/ ROUND BOTTOM 1000 ML 29/32

-                   VIGREUX COLUMN 250 MM 29/32

-                   BENT DOUBLE PIECE 200 MM 29/32

-                   COIL CONDENSER 300 MM 29/32

-                   MEASURING CYLINDER % VOL. 37x360

-          1          THERMOMETER ENCLOSED SCALE RL -10+35 :5

-                   ALCOHOLOMETER 10 -20% OIML

-                   BUNSEN BURNER 13 MM BUTANE

-                   TRIPOD STAND DUR-AL 700X12 MM

-                   CLOSED RETORT RING WITH BOSS HEAD 100 MM

-                   UNIVERSAL CLAMP WITHOUT BOSSHEAD

-                   BURETTE CLAMP WITH BOSSHEAD

-                   GAUZE IRON WIRE WITH CERAMIC FIBRE 14x14 CM

-                   PLASTIC CLIP R-29 RED

-     2          SILICONE TUBE 7X11

 

Fundamentals

 

The alcohol % vol equals the number of liters of absolut etilic alcohol, contained in 100 liters of wine, measured both volumes at the same temperature, and expressed with a precision of 0,1º % vol.

It is determined by simple distillation, of the neutralized liquid, and measured the density of the distilled liquid through areometry.

 

Operative Technique:

 

1. Measure 250 mL of wine with the volumetric flask. Introduce the measured wine in the 1000 mL spherical flask and rinse with 10 mL of distilled water the 250 mL flask and throw them in the distillation flask. Repeat this step 2-3 more times.

 

2. Neutralize the wine sample to analyse with 10 mL of Calcium Oxide solution. Prepare the solution with very precaution with 120 gr. of Calcium Oxide per liter of distilled water.

 

3. Set the distillation flask over the closed retort ring with the iron gauze. Joint it with the vigreaux column and this one with the coil condenser through the double bent. Use the same 250 mL volumetric flask as collector of the distillated sample.

 

4. Set the Bunsen burner under the spherical flask and light it on. Verify the distillation taking care in cooling water being always cold.

 

5. Proceed to the distillation till collecting nearly to the mark of 250 mL (about 2-3 cm below). Light the Bunsen burner of and fill the volumetric flask with distilled water till the mark to obtain the same volume as before.

 

6. Pour the distilled liquid to the 250 mL measuring cylinder, cover it and stirr it.

 

7. Measure the temperature, then dive the 10-20 % alcohometer into the liquid and calibrate it to 20ºC, procuring it to be clean and dry, and let it float.

 

8. When the alcohometer is floating in rest without touching the glass of the measuring cylinder and all air bubbles have been disappeared, read below the meniscus that forms the liquid.

 

Observations

 

In case of distilling wines that has not already finish fermentations or haven't been filtered correctly or that contain carbon dioxide, liable to do foam when boiling them, pour to the wine, before distilling it, some drops of antifoaming silicone.

 

 

TABLES

 

Consult the temperature correction tables in the section Tables à Alcohometric Corrections

 

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