Winegrowers Supplies  -  Laboratory apparatus for testing - juice, wine and cider


Sulfacor
: equipment for determination of total acidity, free SO2 and total SO2, using 10 ml of juice/wine per test (click on the above for instructions in English):-
    
    Glass titration cylinder for measuring total acidity and SO2,
      Blaulauge (blue alkali solution) for measuring total acidity (250ml),
      Purple iodine solution for measuring SO2* (250ml),

    Glass 'measuring/mixing' cylinder for total SO2,
      and additional pair of solutions for total SO2 (250ml each),

* The iodine solution has a 'best before date' on it (usually 2 to 3 months ahead), although we have found it to be sufficiently accurate after 12 months, if kept re-sealed, cool and in the dark.
The acidity solution has a life of a couple of years, and the total SO2 solutions last indefinitely.


Acidometer Set
: with a much taller (slightly narrower) cylinder, for much more accurate reading of total acidity and free SO2
, also suitable for acidity of red wines:-

Contents: graduated titration cylinder, with Blaulauge (blue alkali solution) 250 ml, dropper cap, litmus paper, 32.00

       extra Blaulauge (blue alkali solution) for measuring total acidity (250ml), 10.50

This scale is 0 to 15 grams/litre over a height of 13.5 cms. The Sulfacor cylinder scale is also 0 to 15 gm/l but only over a height of 7.5 cms.

The test procedure and chemicals are the same for Sulfacor and Acidometer.

First, the titration cylinder should be rinsed with the juice or wine, then filled up to the '0' mark on the graduated cylinder.
The drink to be tested must be free from carbonic acid; shake it several times to remove CO2.
The Blaulauge is then added drop by drop and mixed by tilting the cylinder (top covered with the thumb). The drops of solution will eventually neutralise the acid. When it reaches neutral the colour changes to dark green, and if another drop is added then to blue. When it's dark green (slightly bluish) the scale shows the total acid content in grams/litre.

Using the litmus paper for exact measurement, especially in dark juices/wines:-
To ascertain the precise point of colour change, put one drop on the (neutral) litmus paper. Continue titration and repeat until the litmus paper does not change colour (red = acid still present, blue = too much solution has been added). The scale is then read off carefully, showing the acidity content in grams/litre.

       100 ml Jodlosung ** (Iodine solution) for testing free SO2, 8.25

The Acidometer titration cylinder also has a scale for SO2, alternatively the Sulfacor cylinder can be used.

**This iodine solution has a date of production stamped on the label. Storage for best results is 6 months if stored in a cellar (6 to 12C) or fridge (below 6 C), but only 2 months if in a warmer room.


Sample taker from barriques, carbuoys or tanks, 13.20

Must hydrometer: (0 to 130 Oe) with built in thermometer for temperature correction, 23.25

Temperature correction:-
The temperature is read off the thermometer scale inside the hydrometer.
This hydrometer is (like most) calibrated at 15 C (= 59 F); some others are calibrated at 15.6 C (= 60 F) or 20 C (= 68 F).
Higher temperatures thin the liquid slightly and result in lower readings than you'd get at the calibrated temperature.
Examples of the correction to apply to the specific gravity reading:-

Temp (C) Temp (F)   Density   Correction in Oe
________ ________    _______   ______________
   0            32           0.99987     subtract 0.74
 3.98          39.16       1.00000     subtract 0.87
   5            41           0.99999     subtract 0.86
  10           50            0.99973     subtract 0.6
  15           59            0.99913           0
  18           64.4         0.99862      add 0.51
  20           68           0.99823       add 0.9
  25           77           0.99707       add 2.06
  30           86           0.99567       add 3.46
  35           95           0.99406       add 5.07

The correct way to use a hydrometer is to spin it gently in the grape juice, or wine, for which the specific gravity is to be measured. Twisting the hydrometer removes most of the air bubbles from its surface which can otherwise invalidate the measurement. Do not drop the hydrometer into a container from a height, or it's likely to be broken. A graduated cylinder is normally used for this purpose:-

Glass cylinder (trial jar)  370 mm tall, 250 ml graduated, 14.25


Ebulliometer
:

    for testing alcohol in wine or cider, 599.00

 

Secondhand:-

Alla (France) hydrometer with scales (at 20 C), 10 :-
   Specific gravity, 0.980 to 1.150
   Potential alcohol by volume, 0 to 15%
Not as precise as the Zeal ones but gives a good idea of how the fermentation is progressing.

Accurate thermometer, made by Youngs, - 10 to + 110 C, 76mm immersion, 6.
This can be used to calculate the correction to be applied for temperature.

Also beakers, boiling flasks, conical flasks, volumetric glassware, reagent bottles, funnels, condensers, pipettes and other pieces of laboratory glassware - details and prices on request.


Prices shown are exclusive of Vat.
Delivery usually will need to be charged at cost.

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