WATER/CHEMICAL SECTION IN BREWERY COMPANIES – WHAT DO THEY DO?

1.            PH TEST

     This measures the level of acid and alkaline in the water.

 Procedure:

1.      Rinse the PH electrode with the sample twice

2.      Place the PH electrode in the sample and allow beating

3.      When stop beating, read off the result.

2.          FREE CHLORINE

Apparatus:

 spectrophotometer, DPD chlorine reagent.

Procedure:

1.      On the spectrophotometer, press 80 and ENTER

2.      Dial to 430.

3.      Insert the cell rinser into sample compartment.

4.      Fill 10mls cell with sample (i.e. blank). Place it into the cell holder and close the light shield. Then press “ZERO”.

5.      Fill another 10 ml with sample and add one sachet of DPD free chlorine powder and shake for 20 seconds.

6.      Place the sample into cell holder, close the light shield and press ”READ”

7.      Then take the final reading.

SPECTROPHOTOMETER

3.          PHENOLPHTHALIEN ALKALINITY

     Procedure:

1.      Measure 100mls of sample and pour into a flask using a measuring cylinder.

2.      Add 3-5 drops of phenolphthalein and shake.

3.      If the colour remains, then the titre value is 0.

4.      If the colour changes to rose pink, then titrate to get titer value with 0.1N HCl until it turns colouless. Then read off.

4.   METHYL ORANGE ALKALINITY

Procedure:

1.      Measure 100mis of sample and pour in a flask.

2.      Add 5 drops of methyl orange.

3.      NB. If changes to orange or yellow colour , titrate  with 0.1N HCl till it changes to rose pink. Then take your titre value.

5.   TOTAL HARDNESS

Procedure:

1.      Measure 100mls of the sample into a conical flask

2.      Add the titre value of 0.1N HCl acid of the methyl alkalinity

3.      Add 4mls of ammonium buffer into the flask

4.      Add little quantity of Eucrom black into the flask (the colour changes to purple)

5.      titrate with 0.2N EDTA(the colour changes from purple to blue)

6.      Then read off from the burette. (Multiply the titre value by 1.12 to convert it to °G)

 6.    CALCIUM HARDNESS

  Procedure:

1.        Measure 100mls of the sample into the conical flask

2.        Add the titre value of 0.1N HCL acid of methyl alkalinity

3.        Add 1 ml of KOH into the flask

4.        Add little quantity of muroxide(the changes to pink)

5.        titrate with 0.2N EDTA(the colour changes from pink to purple)

6.        Read off from the burrette and multiply by 1.12

7.   MAGNESIUM HARDNESS

         The difference between the total hardness and calcium hardness gives the value for magnesium hardness.