CHAPTER X

INTERMITTENT CANNING OR FRACTIONAL STERILIZATION

In some parts of the United States, particularly in the South, such vegetables as corn, beans, peas, squash, spinach, pumpkin, etc., are canned by what is known as the fractional sterilization, or the so-called Three Days Process.

Southern canning experts have had trouble with certain vegetables, such as those named, when they canned these vegetables in the wash boiler by the cold-pack or one period method. They say that the climatic conditions are so different in the South that what is possible in the North is not possible in the South.

The vegetables are prepared, blanched, cold-dipped and packed as in the cold-pack method and the filled cans or jars are processed in the wash boiler or other homemade outfit a given length of time three successive days.

After each day's processing the cans should be cooled quickly and set aside, until the next day.

The method is as follows:

Process or sterilize glass jars for the required number of minutes on the first day, remove from canner, push springs down tightly as you remove the jar from the canner.

On the second day raise the springs, place the jar in the canner, process or boil for the same length of time as on the first day. Remove from the canner and seal tightly. Set aside until the third day, when the process should be repeated.

For this canning a good spring-top jar is good, although the Mason jar type of top will serve for one year; after one year of use it is advisable to fit old Mason jars and similar types with new tops.

If using the screw-top jars, such as the Mason, do not disturb the seal at the second and third processing unless the rubber has blown out.

This method is only necessary when depending upon boiling water or condensed steam to do the work.

A steam-pressure canner or pressure cooker is used in the South and many other places to avoid bothering with vegetables three successive days.

The steam canner or pressure cooker soon pays for itself in time, energy, and fuel saved as the vegetables may be canned at high pressure in one processing.

The following time-tables are those used in the South and will tell you exactly how long to blanch and process all products. The preparation of vegetables and fruits is the same as in the one-period method, but the time of blanching and sterilizing differs as the time-table indicates.

TIME-TABLE FOR PRODUCTS IN GLASS

(Hot-Water Canner)

TomatoesBLANCH 1 min.LIQUOR No waterSIZE JAR QuartPROCESS OR BOIL 30 min.
Tomatoes1 min.No waterPint25 min.
String beans (very young and tender)3-5 min.Brine[1]Quart1 hr. 15 min.
Sweet potatoesCook ¾ done2 tablespoonfuls waterQuart3 hrs.
SauerkrautBrine[1]Quart40 min.
Baby beetsCook ¾ doneHot waterQuart1 hr. 40 min.
Baby beetsCook ¾ doneHot waterPint1 hr. 20 min.
Soup mixtureBoil down thickQuart1½ hrs.
Apples1 min.No. 1 sirupQuart15 min.
Berries1 min.No. 1 sirupQuart13 min.
FigsNo. 3 sirupQuart30 min.
Peaches1-2 min.No. 2 sirupQuart25 min.
Pears1 min.No. 3 sirupQuart25-35 min.
CherriesNo. 3 sirupQuart30 min.

[1] Brine is made of 2½ ounces (⅓ cup) of salt to 1 gallon of water.

To make sirups recommended, boil sugar and water together in proportions given below:

TIME-TABLE FOR PRODUCTS IN GLASS

The following vegetables should be processed the same length of time on each of three successive days:

BLANCHLIQUORSIZE JARPROCESS OR
BOIL ON EACH
OF THREE
SUCCESSIVE DAYS
Corn2 min. on cobWater, salt and sugarPint1½ hr.
Garden peas1 to 4 min.Water, salt and sugarQuart1½ hr.
Asparagus1 min.Brine[1]Pint1 hr. and 20 min.
Asparagus1 min.Brine[1]Pint1 hr.
Lima beans2 to 4 min.Brine[1]Pint1 hr. and 25 min.
Okra3 min.Brine[1]Quart1½ hr.
Okra3 min.Brine[1]Pint1 hr. and 15 min.
SquashCook doneQuart1¾ hr.
SquashCook donePint1 hr. and 25 min.
PumpkinCook doneQuart1¾ hr.
PumpkinCook donePint1 hr. and 25 min.
Spinach4 min.Brine[1]Quart1½ hr.
Spinach4 min.Brine[1]Pint1 hr. and 15 min.

[1] Brine is made of 2½ ounces (⅓ cup) of salt to 1 gallon of water.

TIME-TABLE FOR PRODUCTS IN TIN

(Hot-Water Canner)

BLANCHLIQUORNO. CANEXHAUST
MINUTES
PROCESS
OR BOIL
Tomatoes1 min.No water3325 min.
Tomatoes1 min.No water1051 hr.
String beans3-5 min.Brine[1]331 hr.
String beans3-5 min.Brine[1]1032 hrs. and 20 min.
Sweet potatoesCook ¾ done2 tablespoonfuls water333 hrs.
Baby beetsCook ¾ doneBrine[1]331½ hrs.
Soup mixtureBoil down thick231 hr.
Apples1 min.No. 3 sirup338 min.
Berries1 min.No. 4 sirup3310 min.
Berries1 min.No. 4 sirup10332 min.
FigsNo. 4 sirup2325 min.
Peaches1 min.No. 4 sirup3320 min.
Pears1 min.No. 4 sirup3320 min.
Pears1 min.No. 4 sirup10335 min.

[1] Brine is made of 2½ ounces (⅓ cup) of salt to 1 gallon of water.

To make sirup recommended, boil sugar and water together in proportions given below.

TIME-TABLE FOR PRODUCTS IN TIN

The following vegetables should be processed the same length of time on each of three successive days:

BLANCHLIQUORNO. CANEXHAUST
MINUTES
PROCESS OR
BOIL ON EACH
OF THREE
SUCCESSIVE DAYS
Corn2 min. on cobWater, salt and sugar2101 hr. and 15 min.
Garden peas1 to 4 min.Water, salt and sugar231 hr. and 15 min.
Asparagus1 min.Brine[1]331 hr.
Asparagus1 min.Brine[1]2350 min.
Lima beans2 to 4 min.Brine[1]231 hr. and 10 min.
Okra3 min.Brine[1]331 hr. and 10 min.
Okra3 min.Brine[1]2350 min.
SquashCook soft and creamy331½ hr.
SquashCook soft and creamy231 hr. and 10 min.
PumpkinCook soft and creamy331½ hr.
PumpkinCook soft and creamy331 hr. and 10 min.
Spinach4 min.Brine[1]331 hr. and 15 min.
Spinach4 min.Brine[1]231 hr.

[1] Brine is made of 2½ ounces (⅓ cup) of salt to 1 gallon of water.

You will notice in the time-table for tin, that there is a column for "Exhausting." After the can is packed and capped it is placed in the canner of boiling water to within 1 inch of the top of the can where it remains the number of minutes, usually three, indicated on the time-table. This is done to force the air from the can through the little hole left open in the top, and is called exhausting. Cans that are not exhausted frequently bulge after processing and are looked upon with suspicion. Cans exhausted too long frequently cave in at the sides. The time-table should be used carefully and followed strictly in this part of the process. Tin cans do not require exhausting in the Northern and Western states.

TIME-TABLE FOR CANNING VEGETABLES STEAM PRESSURE

VEGETABLEPROCESS,
MINUTES
TEMPERATURE,
DEGREES
FAHRENHEIT
PRESSURE
POUNDS
Asparagus3024010
String beans, No. 24524010
String beans, No. 35524010
Beets302285
Corn8025015
Okra3024010
Peas4524010
Soup, concentrated vegetable3022810
Spinach3022815
Sweet potatoes7025015

Corn, lima beans and peas should never be packed in larger container than No. 2. Corn is cut from cob after blanching.

The brine used is made of 2½ ounces salt to 1 gallon of water, except for asparagus, which contains 4 ounces to 1 gallon.

Beets and rhubarb when packed in tin must be put in enamel-lined cans.

Process pints as for No. 2 cans; quarts as for No. 3 cans, adding 10 minutes to each period.

String beans when more mature should be processed at 15 pounds pressure for 30 minutes for No. 2, and 45 minutes for No. 3.