Sensory Evaluation of Dahi

i. Desirable Characteristics and Defects of Dahi

i) Colour and appearance: The colour of dahi ranges from creamy yellow for cow to creamy white for buffalo dahi. It should be pleasing, attractive and uniform without showing any sign of browning and visible foreign matter. Dahi should have smooth and glossy surface without appearance of any free whey on sides or top. A cream or malai layer on the top is indication of wholesomeness and purity, hence desirable.

ii) Flavour: A pleasant, sweetish aroma and a mild clean acid taste are looked for in dahi. It should be free from any off flavour. A good diacetyl flavour is always desired in dahi. Skim milk dahi lacks the natural rich flavour and considered as flat. Dahi shall not show any sign of bitterness, raw, yeasty, cheesy, sharp, and unclean off flavours.

iii) Body and texture: Good dahi is a weak gel like junket when made from whole milk. The body should be firm, homogenous and free from gas holes/ bubbles. On cutting it should appear clean/sharp. The surface should be smooth, preferably with a creamy layer. Defects like grainy/lumpiness, ropy, shrunken, thin and wheying off should be absent in dahi.

iv) Acidity: Generally acidity in the range of 0.75 to 0.85%, as lactic acid is appropriate for good quality dahi. Excessive acidity imparts too much sourness/ sharp/ astringent taste to the product, whereas low acidity in dahi is considered as raw/bland.

ii. Score Card of Dahi

The following score card is suggested for sensory evaluation of dahi (Table)

Score Card for dahi

iii. Scoring Technique of Dahi

i) Temper dahi to about 10-15oC for proper judging.

ii) Note the condition of container/package for fullness, cleanliness and general appearance.

iii) Remove the closure lid of the package and immediately observe the aroma by inhaling the product. Simultaneously, examine the appearance of dahi for uniformity of colour and presence of visible extraneous/foreign matter.

iv) Cut the curd by using a knife or spoon and observe for the firmness and evenness of cut. Also observe the interior of dahi mass for smoothness, presence of air/gas holes and free whey.

v) Place a spoonful of dahi in the mouth. Ascertain the taste and aroma of product. While manipulating in mouth also note the tactual properties on the tongue and between teeth for grittiness/graininess..

vi) Note whether the acidity level is pleasant and typical to the product.

vi) Finally rinse your mouth with water.