10 March, 1917.] Sideliyhts on the Olive Oil Industry. 159 



available. In a wider sense, were there large olive groves, the itinerant 

 friiif-pickers would be enabled to have more constant labour, since they 

 could continue their work after picking the late summer crops of grapes 

 and other fruits, by picking the early varieties of olives during 

 autumn, and the lat« varieties at winter time. This leads to the 

 thought that the early varieties of olives should be planted in the one 

 block, and the later in another, and so facilitate cultivation, and cheapen 

 the cost of labour in picking. Another practic^ point gained by 

 experience is, that it is much cheaper and less irksome to pick large- 

 fruited varieties. It is one of those points where the human as well as 

 the practical elements play a part. It is often said that the large 

 varieties contain less oil. This may be true of many of the large 

 varieties, but at the college, where some ten or more growers send their 

 olives to be treated, the highest percentage of oil extracted is from a 

 large olive grown at Mooroopna, and introduced, I believe, by Mr. John 

 West over twenty years ago. Unfortunately, the name of the variety is 

 not available. The fruit when green has an acrid bitter taste. As it 

 ripens, it becomes a yellowish-green, then streaks of purple appear, and 

 ultimately the whole fruit becomes dark-purple, and finally black when 

 fully matured. The pulp when ripe varies from a light to a dark-purplo, 

 and in some instances it is quite black. As the fruit ripens it loses most 

 of its bitter taste, and a few varieties are relatively sweet. In cold 

 climates the olive is often sufficiently ripe for picking when yellow. The 

 size of well-grown fruit varies from | to li inches long, according to 

 the variety. The stone varies in size in different varieties of otherwise 

 similar dimensions. As the oil from the kernel is not as good as that 

 from the pulp, the small-stoned varieties with relatively more pulp are, 

 generally speaking, the better for commercial purposes, and, especially 

 so for pickling. The shape and size of the stone give an indication of 

 the name of a variety, as also do the shape and size of the leaf and the 

 form of growth of the tree. 



The proper time to pick the olives for oil extraction is just as they 

 are ripe. They then have the maximum amount of good oil. As they 

 become over ripe the percentage of oil present is less and of an inferior 

 quality. Practically just as they become purple is the best time to pick 

 the fruit, hut in order to cope with a large area it is well to start when 

 the bulk of the berries on the trees are purple. The oil made from such 

 olives is more limpid, or what the trade terms thin, in contrast to a 

 fat or thick oil, in which there is a higher percentage of stearine to 

 olein or true oil. Every one who has seen olive oil in cold weather will 

 have noticed the white solid matter thrown down. This is the stearine, 

 and its presence is an indication that the oil is olive oil, or that the 

 greater percentage of it is so. The stearine quickly dissolves when 

 warmed. The higher the percentage of olein present the better the oil. 

 The colour of the oil is an important matter in the commercial world. 

 The colour depends on various conditions, viz. : — the state of maturity 

 of the fruit, the variety, the season, and the soil. Olives picked over 

 ripe give a dark-yellowish, unattractive oil. whilst those picked just ripe, 

 or a little before, give a lighter coloured, limpid, and attractive oil, with 

 a tinge of green in it. Heavy soils produce a darker, and generally 

 inferior oil to those of a good loamy texture. With plenty of lime in 

 the soil the oil is lighter in colour, bright, and more attractive. 



