346 CALIFORNIA FRUITS I HOW TO GROW THEM 



pulp is put in each cloth, so that when the cloth is folded back it makes 

 a cheese about three feet square and three inches thick. Ten or more 

 of these cheeses are placed one above the other, with slats between, and 

 the pressure applied gently at first. From the liquid which runs out 

 first is made the very finest oil, known as "virgin oil." The pressure is 

 then increased very gradually until the full power of the machine is 

 reached. This presses out the second quality of oil, which is generally 

 mixed with the first. After obtaining all the oil possible by the first 

 pressure the "cheese" is taken out, thoroughly broken up in hot water, 

 and again pressed. This yields the third quality, which is very much in- 

 ferior to the first and second. Sometimes the "cheese" from the first 

 pressing is thoroughly broken up with cold water and pressed again 

 before being treated with hot water. In this way a little oil is obtained 

 that differs a little from the second quality, and may be mixed with it. 

 After this a certain amount of oil still remains in the "cheese," but it 

 can be extracted only by very powerful hydraulic presses, or by chemical 

 means, and then is of very inferior quality, and suitable only for burning 

 or for soap making. 



Settling and Clarifying. The liquid from the press is dark col- 

 ored, and it is conducted into a receptacle for settling. Much of the 

 foreign matter quickly separates, the oil appearing on the top. The oil 

 is removed to other receptacles in which it can stand from two to five 

 months for perfect separation of undesirable sediment. These settling 

 tanks may be of well-tinned metal, or of cement lined with glass or other 

 impervious substance. The first settling is conveniently made by means 

 of a funnel-shaped apparatus, which by its conical shape facilitates the 

 rapid deposition of sediment. After standing for twenty-four hours 

 in this apparatus the major part of the sediment is deposited and can 

 be drawn off at the bottom. It is well, before running the oil into the 

 settling tanks, to pass it through two or three inches of cotton wool. 

 This is accomplished by means of a funnel with a perforated, horizontal 

 cross partition, upon which the cotton is placed. It takes, generally, 

 about one month for the oil to settle sufficiently in the first tank, after 

 which it should be drawn off carefully into the second, and so on until 

 it is sufficiently bright. Three rackings are usually sufficient. 



Olives are sometimes ground and pressed in portable cider mills or 

 ground in barley crushers for oil manufacture on a small scale. As the 

 above description shows, oil making is a simple process, and may be 

 carried on at home with rude devices. It is, however, a process requir- 

 ing care and cleanliness, and intelligent personal attention. 



PICKLING THE OLIVE 



Olives are pickled in a green state, as is the case with the imported 

 olives ; or in a ripe state, as largely undertaken in California. No one 

 had any conception at first of the difficulties attending the production 

 of pickled ripe olives which would have the keeping quality demanded 

 in an article of commerce. It is now clearly seen that treating olives to 

 extract the bitterness and to secure firmness, good flavor and keeping 



