206
Hay-Box and Simmering Processes of Preserving Milk
[Vol. XVIII, Part IV
shorter day, or, the period of storage. In the course of the present investigation, neither at Bangalore
nor at Jhallar there was any instance of the actual curdling of the morning milk. Perhaps this might
have been due to the shorter interval (6.7 hours) of preservation. Experimental data obtained
recently in the Dairy Technology Section of the Indian Dairy Research Institute, Bangalore, show
that if milk is collected in hot and humid season and stored at an elevated temperature varying from
120-140°F., curdling of milk takes place within 8 hours. As in actual practice, the preservation
period in the villages may have to be as long as 12 hours, the hay-box method seems to be of doubtful
utility.
Srinivasan and Banerjee [1946] and Rangappa et al [1946], have recently shown that more than
the quantitative, the qualitative distribution of microflora in milk, prior to its ripening, decides the
nature of fermentation and thereby the quality of the curd on which, in turn, will depend the quality
of butter and butter-milk. In the present methods where the evening's raw milk is added to morn-
ing's processed milk, the significance of initial processing on the quality of the curd or butter or butter-
milk is practically lost because it has been observed that the addition of evening's raw milk invariably
introduces coliform contamination which is absent in morning's processed and preserved milk. The
re-entrance of coliform contamination is indicative of the presence of harmful organism which would
eventually frustrate the use of lactic starter in setting up the desired curd. This is borne out by the
fact that the curd in all the methods has been slightly blown up, and possessed of ropy texture, with
the rising up of the curd separately from the whey. Due to this uncertain course of fermentation,
irrespective of the method, butter-milk (lassi) obtained at Bangalore was uniformly of inferior quality.
According to the opinion of Jhallar workers butter-milk from simmering process was slightly more
palatable than that produced by the hay-box method. In Table II are given the range of acidity in
curd and butter as also of moisture and curd content in butter.
TABLE II
Range of acidity in curd and butter and moisture and curd content in butter
Method
1. Hay-box (just boiled) .
2. Simmering (just boiled)
3. Hay-box (boiled for
10 min.)
4. Simmering (boiled for
10 min.)
Acidity (per cent lactic)
Curd
Bangalore
0.70
to
0.85
0.60
to
0.85
0.80
to
0.85
0.75
to
0.90
Jhallar
0.85
to
0.86
0.81
to
0.86
0.86
to
0.89
0.75
to
0.86
Butter
Bangalore
0.20
to
0.27
0.22
to
0.25
0.21
to
0.31
0.22
to
0 31
1
Jhallar
0.21
to
0.22
0.22
to
0.24
0.21
to
0.22
0.22
to
0.24
Moisture per cent
in butter
Bangalore
19.5
to
20.7
19.0
to
25.0
19.0
to
19.5
19.0
to
20.0
Jhallar
21.8
to
22.2
21.9
to
22.1
22.3
to
23.0
21.1
to
23.6
Curd per cent in
butter
Bangalore
1.9
to
2.1
1.9
to
2.1
1.9
to
2.2
1.9
to
2.1
Jhallar
1.2
to
1.6
1.1
to
1.7
1.1
to
1.2
1.4
to
1.0
Outturn of ghee : Notwithstanding the close liaison in the technological details of manufacture
the differences in the origin of the initial raw material and other environmental factors were bound to
affect the quantitative yield of ghee per unit weight of milk taken at the two centres. As the direct
comparison of the data may prove confusing, it is considered convenient to express the relative yields
by hay-box and simmering methods as the coefficient of the yield from the standard cream-butter
method used both at Bangalore and Jhallar. In Table III, the data have been set out accordingly.