Sensory Evaluation of Cheddar Cheese

i. Desirable Attributes of Cheddar Cheese

i) Colour: The colour of Cheddar cheese should be uniform throughout. The most desired colour is very light straw for the natural colour cheese or deep straw or yellow orange for the medium coloured cheese. The cheese should be translucent, that is, it should appear as if one could actually see into the cheese for a short distance.

ii) Finish and Appearance: Cheese with a desirable finish should show flat, parallel ends; square, even edges; an evenly-folded, neat, close fitting bandage or wrapper free from wrinkles; a clean, thin, uniform, close-adhering coating of paraffin, showing no blisters or scales; and freedom from cracks, mold, rot spots, or soiled areas.

iii) Body and Texture: The desired body and texture of cheddar cheese is that which yields a full, solid, close-knit plug possessing smoothness, meatiness, waxiness and silkiness and which is entirely free from gas holes. Such cheese slices well.

iv) Flavour: High quality American Cheddar Cheese has a characteristic cheddar flavour, described as clean, fine, nutty and pleasantly sweet.

ii. Score Card of Cheddar Cheese

The weightage given to different attributes is given in the score card (Table )

Score card for Cheddar Cheese

iii. Scoring Technique of Cheddar Cheese

i) Tempering Cheese: Cheese should be kept in a room at 10-15.5oC for a sufficient of time to secure a uniform temperature throughout all parts of the cheese. A plug taken from warm cheese appears weak bodied while a plug from cold one will appear brittle or corky. Hence, to know the true characteristics of cheese, tempering is must before scoring.

ii) Sampling: It is done with a cheese trier. The edges of a cheese trier are sharper than a butter trier. A trier that cuts a larger plug has an advantage over one of small diameter because it is much easier to detect the degree of openness and the colour defects on the larger plug. Cheese trier is inserted in the middle of the cheese block, rotated at 180o and withdrawn. After drawing a plug of cheese, break the upper 2 cms and put in the hole again from where the plug was drawn.

iii) Sequence of observations

a) Aroma: Immediately after withdrawing the plug of cheese from the block pass it slowly under the nose and inhale strongly to ascertain the aroma. Then examine the remaining plug carefully. Make mental record of all these observations.

b) Colour: Note whether the colour is bright, clear or dull; whether it is uniform, free from mottles or light and dark portions, or it has seams or faded areas surrounding the mechanical holes.

c) Openness: Observe the nature and extent of openness in the cheese. Note whether the holes are regular, angular, rounded, large, or small. Observe also the luster or shine of their inner surfaces and note if they are dry or wet.

d) Body and texture: Hold the ends of the plug by the fore-fingers and the thumbs of the two hands and bend the plug slowly into a semi-circle, observing when it breaks and the nature of the break. Observe carefully whether the plug shows a resistance towards bending and finally breaks suddenly, or bends one half of one third and eventually tears apart slowly.Take one of the broken pieces between the thumb and the fingers and work it up into a uniform mass, observing its resistance to the pressure of the thumb and the fingers. Spread the mass thinly over the palm of the hand with the thumb and observe whether the mass feels smooth, silky, waxy and fine or whether it is sticky, pasty, mealy or crumbly. Reassemble the particles, compress them into a ball, noting meanwhile the response of the cheese to its manipulation. Also note the behaviour of cheese while biting, chewing, mastication and swallowing.

v) Flavour: Place the worked mass (ball) under the nose and observe the aroma.Compare this aroma with that noted when the sample was first removed from the cheese block. Place a small portion of the unworked plug into the mouth, chew it up to the semi-solid state, roll into the mouth, expectorate and note the flavour. Rinse the mouth occasionally with lukewarm saline water (1%), which cleans the mouth satisfactorily to the previous cheese flavours.

iv. Undesirable Attributes of Cheddar Cheese

a) Colour: Some of the commonly found colour defects in cheese are: acid cut (bleached/faded); atypical colour specks (white or black, rust, etc.); mottled and seamy (uneven/wavy). White specks observed in highly ripened cheese are not considered as a defect.

b) Finish and appearance: The judge may look of huffed, uneven size and edges of black, blistered/cracks, light spots, molds, rough and soiled surface defects as these may be correlated with some body and texture and flavor defects in cheese.

c) Body defects: Corky (dry/hard), crumbly, curdy (rubbery), greasy, pasty,spongy, weak (soft) and short.

d) Texture defects: Mealy/grainy (gritty), gassy, sweet curd holes and open.

e) Flavour defects: High acid/sour, bitter, flat, moldy/yeasty, rancid, fruity, whey taint, unclean, tallowy, etc.