MILDURA RESEARCH COMMITTEE. 
(almost imperceptible) appear on a fair proportion of the berries. If 
fruit be not cracked, the process of drying is prolonged; if over-cracked, 
the exposure of sugar results. In the latter case, the keeping qualities 
of the fruit are probably affected, as granulation and massing are more 
likely to result when the sugar of separate berries can be brought into 
close contact. An additional fault in over-cracked fruit is the lability 
to collect, dust on the exposed sugary surfaces while on the drying 
green. In the case of perfectly cured berries, this dust is largely 
removed in the process of stemming and grading. The raising of dust 
on the drying green appears to be inevitable, since heavy loads of fruit 
are brought in at frequent intervals. Much good, however, could be 
done by erecting the separate portions of the drying plant in such 
positions that a minimum of traffic takes place in the immediate vicinity 
of the racks. The procedure adopted by the experimentalist was to 
immerse a dip-tin of sultanas for two seconds. It is inevitable by this 
method that the bunches in the bottom of the bucket receive a slightly 
longer immersion than those on the top. This difficulty was overcome 
to some extent by inclining the tin, introducing the end into the solution, 
and passing the tin through the liquid in the form of a curve. This 
practice is adopted by the majority of dip men.° In this set of experi- 
ments, the following course was adopted with each sample:—A weak 
solution of caustic soda (1 in 60) was prepared, and the solution was 
strengthened, as required, by adding an amount’ of caustic soda cal- 
culated to reduce the water relatively by 5 gallons to each 1 lb. of 
caustic soda. Trials were made at each strength, and the additions 
were continued until the berries became over-cracked. Maximum and 
minimum concentrations were recorded, representing the range in 
concentration within which results were adjudged as satisfactory. All 
dipping was done at boiling point. The figures obtained were as 
follow :— 
Baumé Reading (as gallons of water to 1 Ib. of caustic soda, measure of 
ripeness). (Commercial 99 per cent.) DS 
(a) Virst Cracking. (b) Approaching Over-cracking. 
12.1 a 60 = 40 
13.2 " 50 43 35 
IBN ecu ae 45 ne 35 
14.15. 40 ie Bento TU 
14.2 sept 40 x, 30 
14.75 ms 30 ef 20 
Results show that there is a considerable range for a satisfactory dip 
at each stage of ripening. The cracks in the berries increased in num- 
ber rather than in size, as the dip was concentrated over the ranges 
given above. Variation in the lower figure will naturally occur accord- 
ing to the variations in the judgments of investigators. In the case of 
these experiments, the dip was held to be too strong when long trans- 
verse cracks appeared. The minimum concentration (set a) can safely 
be taken as a guide to a commencing dip. In field practice there is ap- 
parently no advantage in maintaining an exact concentration for each 
stage of ripeness. It will be sufficient to keep within the limits men- 
tioned above. : ee, 5; 
627 
