Page 185 - Agriculture_Form_3

Agriculture for Secondary Schools

Procedure for making yoghurt
Step 1: Boil and cool the milk
(a) Strain the fresh milk through a clean cloth to remove dirt or visible
particles.
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(b) Boil the milk in a clean saucepan for 5 - 10 minutes while stirring
constantly with a clean cooking paddle or ladle to prevent milk from
sticking to the bottom and forming a layer (milk skin) on the surface.
(c) Cool the milk immediately after boiling to a temperature of 40 - 45 ℃.
Check the temperature using the same method learnt in the mala making
procedure.

Step 2: Add the Starter
(a) Add 2 - 3 tablespoons of plain yoghurt or starter culture for every litre
of milk.

(b) Stir gently with a clean spoon to mix thoroughly.

(c) Do not add the starter if the milk is still hot, as this will kill the live
bacteria.

Step 3: Ferment the milk
(a) Pour the mixture into a clean fermentation container with a tight-fitting
lid or a clean cloth tightly wrapped over the top.

(b) Place the container in a warm, undisturbed place (e.g., inside a covered
box or near a warm stove) for 6 - 8 hours.
(c) Do not disturb the container during fermentation.

Step 4: Check and store the yoghurt

(a) After fermentation, the milk should have thickened and developed a
slightly sour taste and pleasant smell.
(b) If not fully set, leave it in a warm place for a few more hours.

(c) Once ready, store the yoghurt in a cool place or refrigerator. It can stay
fresh for up to 7 days.

(d) If refrigeration is not available, yoghurt can be stored for a shorter time
(up to 2 - 3 days, depending on the ambient temperature) in evaporative
coolers or zero-energy cooling chambers (ZECCs).

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