Measuring Alcohol Degree - Selecta DE-1626 Manual De Instrucciones

INSTRUCTION MANUAL CODE 80191 REV D JAN/2020
Alcoholimeter reading
Check that the output of the tube
remains immersed under the water
level.
J
.P. SELECTA s.a.u.
11 Measuring the alcohol degree
11.1 Alcoholometer
The volumetric alcohol degree (written as %Vol) is defined as the number of litres of
Etanol and his homologous (Metanol,etc...) content in 100 litres of wine (or alcoholic
drink in general), all measured at room temperature of 20ºC.
The determination basis is easy: the alkalized sample is distilled and the alcohol % is
measured by means of special graduated aerometers named alcoholometers.
There are other methods to measure the alcohol contend on the distilled (hydrostatic
scale, refractometer,...) but the alcoholometer is the more accurate and repetitive
method.
To obtain accurate results, you must work with a method that considers all factors
that could have influence on the volumetrics and on the alcohol losses.
A complete method is presented here. It could be simplified according to laboratory
requirements.
11.1.1 Material
• Cylinder 250 ml (30cm high)
• Alcoholometers (see «accessories» on Chapter 1).
• Thermometer 0-35ºC resolution 0.5ºC.
• 200ml Calibrated flask (certified) with stopper.
• Bath or oven to work at 20ºC.
11.1.2 Reagents
• Calcium Hydroxide 2 mol/l:
• Anti-foam liquid silicone
• Distilled water.
11.1.3 Production of distilled
In order to not have a negative effect on the results, room temperature must be
20±3ºC.
Material preparation
Store all the material that will be used at 20±0.5ºC (cylinder, alcoholometers, cali-
brated flask, wine, samples..)
Removing CO
If the sample is a young or sparkling wine, proceed to remove the CO
sample or with a ultrasonic bath.
Distilling
• Fill the 200ml calibrated flask up to his mark with the sample. Remove bubbles
(all at 20ºC).
• Pass the content to the Ø80 distillation tube.
• To be sure that all the sample has been passed to the distillation tube, clean 2
or 3 times the calibrated flask with around 10ml of distilled water and add it to the
distillation tube.
• Add around 10ml of calcium hydroxide solution.
• Add some drops of anti-foam silicone solution.
• Use the same calibrated flask to collect the distilled.
• Add around 10ml of distilled water on the calibrated flask and place it on the
DE-1626. Check that the output of the tube remains immersed under the water level
(see figure).
• Start distillation.
levelling
• Once the distillation is finished, add some drops of distilled (see 5.4) up to near
(without arrive) the 200ml mark.
• Put the top on the flask and let it on the 20ºC bath or cabinet for at least 3h.
• Add distilled water at 20ºC until the 200ml mark.
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