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)
Tomatoes | BLANCH | LIQUOR | SIZE | PROCESS OR
| | | JAR | BOIL
-----------------------------------------------------------
| 1 min. | No water |Quart | 30 min.
| | | |
Tomatoes | 1 min. | No water | Pint | 25 min.
| | | |
String beans | | | |
(very young |3-5 min. | Brine[1] |Quart |1 hr. 15 min.
and tender) | | | |
| | | |
Sweet potatoes| Cook ¾ | 2 |Quart | 3 hrs.
| done |tablespoonfuls| |
| | water | |
| | | |
Sauerkraut | | Brine[1] |Quart | 40 min.
| | | |
Baby beets | Cook ¾ | Hot water |Quart |1 hr. 40 min.
| done | | |
| | | |
Baby beets | Cook ¾ | Hot water | Pint |1 hr. 20 min.
| done | | |
| | | |
Soup mixture |Boil down| |Quart | 1½ hrs.
| thick | | |
| | | |
Apples | 1 min. | No. 1 sirup |Quart | 15 min.
| | | |
Berries | 1 min. | No. 1 sirup |Quart | 13 min.
| | | |
Figs | | No. 3 sirup |Quart | 30 min.
| | | |
Peaches |1-2 min. | No. 2 sirup |Quart | 25 min.
| | | |
Pears | 1 min. | No. 3 sirup |Quart | 25-35 min.
| | | |
Cherries | | No. 3 sirup |Quart | 30 min.
| | | |
[Footnote 1: Brine is made of 2½ ounces (1/3 cup) of salt to 1 gallon
of water. To make sirups recommended, boil sugar and water together in
proportions given below:
Sirup No. 1, use 14 ounces to 1 gallon water.
Sirup No. 2, use 1 pound 14 ounces to 1 gallon water.
Sirup No. 3, use 3 pounds 9 ounces to 1 gallon water.
One pint sugar is one pound.]
TIME-TABLE FOR PRODUCTS IN GLASS
The following vegetables should be processed the same length of time
on each of three successive days:
| | |SIZE |PROCESS OR BOIL ON
| BLANCH | LIQUOR |JAR | EACH OF THREE
| | | | SUCCESSIVE DAYS
-----------------------------------------------------------------
Corn |2 min. on cob|Water, salt |Pint | 1½ hr.
| | and sugar | |
| | | |
Garden peas|1 to 4 min. |Water, salt |Quart| 1½ hr.
| | and sugar | |
| | | |
Asparagus |1 min. |Brine[1] |Pint | 1 hr. and 20 min.
| | | |
Asparagus |1 min. |Brine[1] |Pint | 1 hr.
| | | |
Lima beans |2 to 4 min. |Brine[1] |Pint | 1 hr. and 25 min.
| | | |
Okra |3 min. |Brine[1] |Quart| 1½ hr.
| | | |
Okra |3 min. |Brine[1] |Pint | 1 hr. and 15 min.
| | | |
Squash | |Cook done |Quart| 1¾ hr.
| | | |
Squash | |Cook done |Pint | 1 hr. and 25 min.
| | | |
Pumpkin | |Cook done |Quart| 1¾ hr.
| | | |
Pumpkin | |Cook done |Pint | 1 hr. and 25 min.
| | | |
Spinach |4 min. |Brine[1] |Quart| 1½ hr.
| | | |
Spinach |4 min. |Brine[1] |Pint | 1 hr. and 15 min.
[Footnote 1: Brine is made of 2½ ounces (1/3 cup) of salt to 1 gallon
of water.]
TIME-TABLE FOR PRODUCTS IN TIN
(Hot-Water Canner)
| | |NO.|EXHAUST|PROCESS
|BLANCH | LIQUOR |CAN|MINUTES|OR BOIL
Tomatoes |1 min. | No water | 3 | 3 | 25 min.
| | | | |
Tomatoes |1 min. | No water |10 | 5 | 1 hr.
| | | | |
String beans |3-5 min. | Brine[1] | 3 | 3 1 hr.
| | | | |
String beans |3-5 min. | Brine[1] |10 | 3 | 2 hrs. and
| | | | | 20 min.
| | | | |
Sweet potatoes |Cook ¾ |2 tablespoonfuls| 3 | 3 | 3 hrs.
| done | water | | |
| | | | |
Baby beets |Cook ¾ | Brine[1] | 3 | 3 | 1½ hrs.
| done | | | |
| | | | |
Soup mixture |Boil down| | 2 | 3 | 1 hr.
| thick | | | |
| | | | |
Apples |1 min. | No. 3 sirup | 3 | 3 | 8 min.
| | | | |
Berries |1 min. |No. 4 sirup | 3 | 3 | 10 min.
| | | | |
Berries |1 min. | No. 4 sirup |10 | 3 | 32 min.
| | | | |
Figs | | No. 4 sirup | 2 | 3 | 25 min.
| | | | |
Peaches |1 min. | No. 4 sirup | 3 | 3 | 20 min.
| | | | |
Pears |1 min. | No. 4 sirup | 3 | 3 | 20 min.
| | | | |
Pears |1 min. | No. 4 sirup |10 | 3 | 35 min.
[Footnote 1: Brine is made of 2½ ounces (1/3 cup) of salt to 1 gallon
of water. To make sirup recommended, boil sugar and water together in
proportions given below.
Sirup No. 1, use 14 ounces to 1 gallon water.
Sirup No. 2, use 1 pound 14 ounces to 1 gallon water.
Sirup No. 3, use 3 pounds 9 ounces to 1 gallon water.
Sirup No. 4, use 5 pounds 8 ounces to 1 gallon water.
Sirup No. 5, use 6 pounds 13 ounces to 1 gallon water.
One pint sugar is one pound.]
TIME-TABLE FOR PRODUCTS IN TIN
The following vegetables should be processed the same length of time
on each of three successive days:
| | |NO.|EXHAUST|PROCESS OR BOIL ON
| BLANCH | LIQUOR |CAN|MINUTES|EACH OF THREE
| | | | |SUCCESSIVE DAYS
Corn |2 min. on |Water, salt| 2 | 10 |1 hr. and 15 min.
| cob | and sugar | | |
| | | | |
Garden peas |1 to 4 min.|Water, salt| 2 | 3 | 1 hr. and 15 min.
| | and sugar | | |
| | | | |
Asparagus |1 min. | Brine[1] | 3 | 3 | 1 hr.
| | | | |
Asparagus |1 min. | Brine[1] | 2 | 3 | 50 min.
| | | | |
Lima beans |2 to 4 min.| Brine[1] | 2 | 3 | 1 hr. and 10 min.
| | | | |
Okra |3 min. | Brine[1] | 3 | 3 | 1 hr. and 10 min.
| | | | |
Okra |3 min. | Brine[1] | 2 | 3 | 50 min.
| | | | |
Squash | | Cook soft | 3 | 3 | 1½ hr.
| | and creamy| | |
| | | | |
Squash | | Cook soft | 2 | 3 | 1 hr. and 10 min.
| | and creamy| | |
| | | | |
Pumpkin | | Cook soft | 3 | 3 | 1½ hr.
| | and creamy| | |
| | | | |
Pumpkin | | Cook soft | 3 | 3 | 1 hr. and 10 min.
| | and creamy| | |
| | | | |
Spinach |4 min. | Brine[1] | 3 | 3 | 1 hr. and 15 min.
| | | | |
Spinach |4 min. | Brine[1] | 2 | 3 | 1 hr.
[Footnote 1: Brine is made of 2½ ounces (1/3 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
| | |TEMPERATURE,| |
|VEGETABLE |PROCESS,|DEGREES |PRESSURE|
| |MINUTES |FAHRENHEIT |POUNDS |
|Asparagus |30 |240 |10 |
|String beans, No. 2|45 |240 |10 |
|String beans, No. 3|55 |240 |10 |
|Beets |30 |228 | 5 |
|Corn |80 |250 |15 |
|Okra |30 |240 |10 |
|Peas |45 |240 |10 |
|Soup, concentrated | | | |
| vegetable |30 |228 |10 |
|Spinach |30 |228 |15 |
|Sweet potatoes |70 |250 |15 |
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.