THE OLIVE IN PALERMO. 679 



To the paste or mash from which the virgin oil has been extracted, 

 the pips, previously removed, are added, boiling water is poured on 

 pressure again applied, and another and inferior grade of oil expressed. 

 The operation repeated a third time produces a still more inferior grade 

 of oil, used mostly in the arts. 



In all these operations absolute cleanliness is indispensable ; mills, 

 presses, and utensils should be frequently washed in a solution of lye, 

 as the slightest contact with rancid matter will impart a disagreeable 

 odor to the oil. 



In some districts the crushing-mill is dispensed with, the only ma- 

 chinery used being a small screw-press. In such case the sack of olives 

 is placed on the bed of the press, trampled down by men, and then the 

 pressure applied, and the so called "virgin oil " produced. The tramp- 

 ling is repeated, water added, and pressure renewed, and so on, repeat- 

 ing all the operations until nothing remains but the shells of the pips 

 and the dry pulp of the olives. The oil obtained by this method is more 

 dense and mucilaginous than the other. Leaving the press the oil is 

 poured into glazed earthenware jars, well washed with cold water (to 

 which is added a little vinegar) and wiped dry with clean cloths. The 

 best form for these jars is that of a frustrum of a cone reversed. In 

 some cases vessels hollowed out of calcareous stone are used, after be- 

 ing thoroughly cleansed with lime water. These jars or vessels are 

 placed in dry cellars, cool in summer and'sufficieutly warm in winter to' 

 prevent congelation of the oil, as this impedes the deposition of the 

 lees (morchia). 



The winter temperature of these cellars should be from 15 to 18 

 centigrade (59 to 64.4 Fahrenheit). In June the oil should be clear,- 

 and can be poured off into other vessels. 



This first pouring off is the " superfine oil " (olio sopraffino). From 

 what remains in the jars a second pouring off or decanting takes place 

 a month later, and this produces the "fine oil" (olio fino), and in 

 August still another decanting from the bottom brings forth the third 

 grade, called "fat oil" (olio grasso), used in manufactures. 



The purification of the oil and deposition of the lees, or morchia, may 

 be accelerated by washing or rinsing with pure water or a solution of 

 alum. The color of the oil may be bleached, or clarified, by a solution 

 of sulphuric acid and water, in the proportion of 20 to 24 parts of water 

 to 1 of acid. There should be a quarter of an ounce of acid to each 

 pound of oil. The mixture must be placed in a vessel and agitated 

 until it becomes milky, the agitation repeated several times during the 

 first twenty -four hours, and then left quiet for eight days to settle. 

 The oil may then be decanted, and will be found extremely clear and 

 limpid. This process also destroys any bad odors that may linger about 

 the oil, though for this purpose vinegar or alcohol seems better. 



Preparinfj for market. For pickling the largest and most fleshy olives 

 aie selM't(Ml. They should be immersed in pure water for five or six 

 15GA 19 



