Chapter XXV
).
In buying these units don’t be “pulled in” by salesmen talk. Watch for compactness, durability, cleanability, lack of danger in use, replaceable parts, and ease of manipulation. In the use of motors the attachment must be so made that the connections will not be catching in gearing, etc. Above four quarts, hand work is heavy and we would advise turning the freezer by a motor.
In the non-turning freezer, the chamber for the ice and salt is separated from the can so that the freezing mixture cannot enter the ice-cream.
It is cheaper to buy ice-cream, the home-made kind tastes far better. When you buy ice-cream, it is wise to watch the containers in which it comes, and to know where it is made. The Government is very particular, but slight slips in the ice-cream organizations can breed the most dangerous of bacilli. At home you can watch everything; above all, cleanliness of ingredients.
FREEZING MIXTURE
The greatest of all the science of ice-cream making is the mixture of ice and salt. Most cook books say three parts ice to one of salt for home use. For hardening after it is frozen eight parts of ice to one of salt, and the mixture must cover the can entirely, top and sides.
Of course, the ratio of ice to salt regulates the freezing. The United States Government Bulletins are full of these ratios if you want to look up this matter.
On this subject Bowen of the United States Department of Agriculture in Bulletin 98 says:
“When two solid bodies, as salt and ice, mix to form a layer, a certain amount of heat becomes latent, called the latent heat of solution. Since this latent heat is taken from the mixture itself the temperature falls correspondingly. The temperature obtained by a salt and ice mixture depends on relative proportions of the mixture and to less extent on the salt at which the heat is supplied from the outside, the size of the ice lump and salt particles and the amount and density of the resulting brine. Hence it is impracticable to give other than approximate temperatures with fixed ratios of salt and ice.”
It usually takes thirty minutes at least to freeze a gallon of ice-cream.
FREEZERS
Electric freezers come from about $75 up and can be had for alternate (A. C.) or direct (D. C.) current.
The advantage of the freezer with its own directly-connected motor, rather than a motor which has to be connected, is readily apparent to those who have suffered the annoyance of belting, pulleys, and countershafts. Being self-contained, such an outfit may be readily located at will; to operate merely requires securing it in place and connecting the wires. You have, therefore, no belts with attendant annoyance and expense, no countershaft with its necessity for continued attention and causing vibration, nor is there dirt and oil being thrown here and there. In addition to the mechanical advantages secured by the motor-driven ice-cream freezer unit, there are had by its use cleanliness and increased space.
Every freezer should be so made that the action of scrapers and dasher is continuous. Some freezers have a device in which the scrapers are hung on the dasher so their lower ends rest on the bottom of the can, and the friction between ends of scrapers and can bottom when in motion moves the scrapers against the side of the can, and holds them there positively and continuously.
TUBS
The tubs should be strong and if possible bound with welded wire hoops or metal bands. If the tub is metal this is unnecessary. Tubs are made of pine, white cedar, etc. The zinc tub is a good substitute for the wooden tub, but the wooden one is good if made water tight and smooth and easy to clean. All parts of the freezer should be non-rustable, especially the can.
The best cans are made with drawn-steel bottoms. They do not leak, do not fall out, as may happen with those having the tin plate or cast bottoms.
The best bodies of the can are made of heavy tin plate. The top of can is strongly wired and turned over, while the bottom of can is made to fit over and under the drawn steel bottom.
All gears must be completely covered so that neither ice nor salt can get in the cogs nor the fingers be caught and injured. Some freezers have gearing enclosed in a box-like fixture.
The inside parts touching the cream should be of harmless metal, generally of pure block tin. All outside parts should be smoothly finished, galvanized usually.
The ice space between the can and the tub must be so arranged as to use the least amount of ice and salt, and freeze as quickly as possible.
The cross bars which connect the handles and cover and clamp on the opposite side are often a source of agony. These must be simple in operation. Some freezers have a clamp, some a key. This is a matter of choice and manufacturer. Some cross bars are hinged and others are dove-tailed.
Freezers are supplied with fly wheel instead of cranks to turn. The fly wheel costs a little more but it is far more convenient, as it requires less turning.
Some freezers have a glass peep hole in the cover of can so one can see the progress of the freezing and obviate loss of time and cold by opening the can.
Scrapers are made of rolled steel bars ground straight and fine to fit can and to insure clean scraping of the cream, so that all parts of the mixture are being frozen continuously.
The dashers and beater are usually of malleable iron heavily coated with pure block tin. Generally (and better so) there is one scraper for the bottom of the can and two metal scrapers for side.
BUYING FREEZERS
The same principals hold in buying freezers as any other culinary utensil. They must be seamless, smooth, easily cleaned, non-dangerous, non-corrosive, non-chipping, and be made by a reputable manufacturer.
Besides the freezer must have ease in running, quick freezing, economy, convenience, and give practical results.
Freezers are equipped with best standard motors. The motors should be so placed as to eliminate danger of motors burning out or being injured by careless handling of the ice and salt.
In ordering a motor outfit include the following--your voltage, Direct or Alternating Current; if Alternating what Cycle and Phase. (See
## Chapter I ).
Buy a freezer with thought. All machinery pays better when the best is bought and close attention has been given to the purchase.
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