The first process of the oil mill is the crushing of the olives. The
crushing machine generally used consists of a circular tub or trough
of stone or bricks, covered with cement, having a stone floor, on which
revolves a heavy stone wheel, or an axle, one end of which is attached to
and works on a pin or pivot set in the centre of the trough. This
mill-wheel crushes and grinds as it rolls over the rolls, while olives
are constantly pushed by a scraper into its path. This may be worked
by hand, by horses, by oxen, by steam or water power. The stone
should be non-porous lest it absorb oil, which may become rancid.
During the process of crushing, pressing, depositing and clarify-
ing, too extreme cold chills the oil and checks its flow. In cold weather
it is desirable to have moderate artificial heat in the mill. When clari-
fied the oil should be put in a cool place and in cool receivers, like tanks
of tiles, bricked, lined with marble or glass. The Italian terra-cotta
lined tanks are the best. The Italians use wooden tanks lined with
tin and also brick tanks lined with a fine cement. Wood is not desir-
able ; the oil which soaks into it is liable to turn rancid. Wood alone
lacks the coolness required.
Sufficient pure water and extreme cleanliness are the essentials of oil
production for table use. All the different parts of the machine must
be kept clean by constant washing with hot water and soda. Smoke
from fires must be prevented and smoking must be forbidden in the
mill because oil absorbs odors and flavors readily.
To keep oil in good condition needs great care and attention. The
clear oil ought to be separated from the turbid at once, for the longer
the oil remains on the lees the more apt it is to contract a rancid or
bad odor. When the oil has been decanted or turned off several times,
as the needs may be, filtered through dry moss, carded cotton, sand,
LABORATORY cook BOOK. 67
plaster, charcoal, etc., it must be stored in a place which is sheltered
both in summer from the heal and in winter from the cold.
If the earth is very rich and the growth of the trees is exceedingly
rank or strong, this forced vegetation will produce fruit that will im-
part a peculiar taste to the oil, and in a short time it will become
so rancid that its market value will be greatly depreciated. When
a very dry season occurs with frequent and intensely hot winds, the
growth is checked, the stem of the fruit is dried and berries get hard,
dry and shriveled. In this case the oil acquires a peculiar woody
flavor.
The oil will most readily absorb any odor to which it may be ex-
posed, and when this is derived from tobacco smoke, onions, etc., it
lowers its value. A smoky chimney in the neighborhood of the room
where the oil is being made or any lack of cleanliness will injure the
oil greatly. Many things contribute to the rancidity in olive oil, such
as excessive heat, contact with the air, contact with metals that can
be dissolved by the natural acids of the oil.
Page 38
Presented as published in 1914. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
The first process of the oil mill is the crushing of the olives. The crushing machine generally used consists of a circular tub or trough of stone or bricks, covered with cement, having a stone floor, on which revolves a heavy stone wheel, or an axle, one end of which is attached to and works on a pin or pivot set in the centre of the trough. This mill-wheel crushes and grinds as it rolls over the rolls, while olives are constantly pushed by a scraper into its path. This may be worked by hand, by horses, by oxen, by steam or water power. The stone should be non-porous lest it absorb oil, which may become rancid.
During the process of crushing, pressing, depositing and clarifying, too extreme cold chills the oil and checks its flow. In cold weather it is desirable to have moderate artificial heat in the mill. When clarified the oil should be put in a cool place and in cool receivers, like tanks of tiles, bricked, lined with marble or glass. The Italian terra-cotta lined tanks are the best. The Italians use wooden tanks lined with tin and also brick tanks lined with a fine cement. Wood is not desirable ; the oil which soaks into it is liable to turn rancid. Wood alone lacks the coolness required.
Sufficient pure water and extreme cleanliness are the essentials of oil production for table use. All the different parts of the machine must be kept clean by constant washing with hot water and soda. Smoke from fires must be prevented and smoking must be forbidden in the mill because oil absorbs odors and flavors readily.
To keep oil in good condition needs great care and attention. The clear oil ought to be separated from the turbid at once, for the longer the oil remains on the lees the more apt it is to contract a rancid or bad odor. When the oil has been decanted or turned off several times, as the needs may be, filtered through dry moss, carded cotton, sand, plaster, charcoal, etc., it must be stored in a place which is sheltered both in summer from the heat and in winter from the cold.
If the earth is very rich and the growth of the trees is exceedingly rank or strong, this forced vegetation will produce fruit that will impart a peculiar taste to the oil, and in a short time it will become so rancid that its market value will be greatly depreciated. When a very dry season occurs with frequent and intensely hot winds, the growth is checked, the stem of the fruit is dried and berries get hard, dry and shriveled. In this case the oil acquires a peculiar woody flavor.
The oil will most readily absorb any odor to which it may be exposed, and when this is derived from tobacco smoke, onions, etc., it lowers its value. A smoky chimney in the neighborhood of the room where the oil is being made or any lack of cleanliness will injure the oil greatly. Many things contribute to the rancidity in olive oil, such as excessive heat, contact with the air, contact with metals that can be dissolved by the natural acids of the oil.