ECONOMY TEST FOR TITRATABLE ACIDITY (TA) TEST KIT No. 2
(For more accurate results than Test Kit No. 1) Items Required
Retort Stand, Economy: 200 x 120m, 60cm Rod
Bosshead (Standard) CLAMP (H/DUTY) – 4 PRONG
BURETTE, ST. BORE, CLASS B – 25ML
Filter Funnel. Plastic – 40mm
Beaker, Squat, Grad. Pyrex – 250ml
Phenolphthalein Indicator, 1% – 50ml
Sodium Hydroxide 0.10M – 500ml
Charcoal, activated – 40g
Filter Paper, Economy, No.1 – 150mm
Filter Funnel, Plastic – 100mm
Stirring Rod, Glass: 30cm x 7mm
Erlenmeyer Flask, Grad.Pyrex – 250ml
10ml Pipett,e Volumetric, A, Glass
Method – Red Wine
1. Pour 50ml of red wine into a 250ml glass beaker. Add 1 teaspoon of activated carbon.
Mix thoroughly. Leave to stand for 5-10 minutes.
2. Fold a No.1 filter paper (150mm) into quarters and place in a 100mm filter funnel located in a 250ml erlenmeyer flask. Pour the carbon/red wine mixture
into the filter funnel containing the filter paper.
3. The filtered wine should be clear. If a red or pink colour still occurs then add the filtered wine back into the filter funnel until the filtered wine is clear.
4. Use a 10ml bulb (volumetric) pipette to add 10ml of the clear filtered wine to a 250ml erlenmeyer (conical) flask plus approx. 30ml distilled water.
5. Add 3 drops of Phenolphthalein Indicator to the 250ml flask.
6. Now place a 40mm plastic funnel in the top of the 25ml burette* (make sure that the nylon stopcock is closed) and pour 0.10M Sodium Hydroxide into the
burette (almost to the top of the burette – the actual level is not important)
Note the initial volume of 0.10M Sodium Hydroxide(0.10M NaOH) in the graduated stem of the 25ml burette) * (Note: the 25ml burette should be held firm in 4 prong clamp, connected to a bosshead which is connected to the 60cm rod of the retort stand)
7. Now open the stopcock of the 25ml burette and slowly add the 0.10M sodium hydroxide to the 250ml flask while gently stirring the flask. As the sodium
hydroxide is added, the colour of the phenolphthalein indicator will become an increasingly purple colour before disappearing to the colour of water. The
end point (ie end of the titration) is reached when one drop of the 0.10M sodium Hydroxide added from the burette, changes the colour of the solution in
the 250ml flask, from a clear, water colour to a faint, permanent, pink/purple colour.
(Note: This faint pink/purple colour should remain for about 45 seconds, otherwise add another drop of the sodium hydroxide from the burette until a
faint, pink/purple colour is obtained.)
the final volume of 0.10M Sodium Hydroxide (0.10M NaOH) remaining in the 25ml burette.
Subtract the initial volume 0.10M NaOH from the final volume of 0.10M NaOH in the 25ml burette.
8. The Titratable Acidity is calculated as follows:
Titratable Acidity (TA) = [Final volume – Initial volume of 0.10M NaOH ] x 0.75 = grams /litre of tartaric acid present in the wine
Example: The Initial volume of 0.10M NaOH in the 25ml burette = 1.0ml
The Final volume of 0.10M NaOH in the 25ml burette = 9.0ml
Titratable Acidity(TA) = 9.0ml – 1.0ml = 8ml x 0.75 = 6g/Litre of Tartaric acid
Method – White Wine
Proceed from Step No. 4