Especialidades JA/Conservación de alimentos/Respuestas
Conservación de alimentos
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Contenido
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1a
1b
1c
1d
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1h
1i
1j
1k
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1m
1n
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2a
Lid safety fuses are thin metal inserts or rubber plugs designed to relieve excessive pressure from the canner. Do not pick at or scratch fuses while cleaning lids. Use only canners that have the Underwriter's Laboratory (UL) approval to ensure their safety.
Replacement gauges and other parts for canners are often available at stores offering canning equipment or from canner manufacturers. When ordering parts, give your canner model number and describe the parts needed.
Follow these steps for successful pressure canning:
- Put 2 to 3 inches of hot water in the canner. Place filled jars on the rack, using a jar lifter. Fasten canner lid securely.
- Leave weight off vent port or open petcock. Heat at the highest setting until steam flows from the petcock or vent port.
- Maintain high heat setting, exhaust steam 10 minutes, and then place weight on vent port or close petcock. The canner will pressurize during the next 3 to 5 minutes.
- Start timing the process when the pressure reading on the dial gauge indicates that the recommended pressure has been reached, or when the weighted gauge begins to jiggle or rock.
- Regulate heat under the canner to maintain a steady pressure at or slightly above the correct gauge pressure. Quick and large pressure variations during processing may cause unnecessary liquid losses from jars. Weighted gauges on Mirro canners should jiggle about 2 or 3 times per minute. On Presto canners, they should rock slowly throughout the process.
- When the timed process is completed, turn off the heat, remove the canner from heat if possible, and let the canner depressurize. Do not force-cool the canner. Forced cooling may result in food spoilage. Cooling the canner with cold running water or opening the vent port before the canner is fully depressurized will cause loss of liquid from jars and seal failures. Force-cooling may also warp the canner lid of older model canners, causing steam leaks. Depressurization of older models should be timed. Standard-size heavy-walled canners require about 30 minutes when loaded with pints and 45 minutes with quarts. Newer thin-walled canners cool more rapidly and are equipped with vent locks. These canners are depressurized when their vent lock piston drops to a normal position.
- After the canner is depressurized, remove the weight from the vent port or open the petcock. Wait 2 minutes, unfasten the lid, and remove it carefully. Lift the lid away from you so that the steam does not burn your face.
- Remove jars with a lifter, and place on towel or cooling rack, if desired.
2b
Boiling water canners are made of aluminum or porcelain-covered steel. They have removable
perforated racks and fitted lids. The canner must be deep enough so that at least 1 inch of
briskly boiling water will be over the tops of jars during processing. Some boiling-water canners
do not have flat bottoms. A flat bottom must be used on an electric range. Either a flat or ridged
bottom can be used on a gas burner. To ensure uniform processing of all jars with an electric
range, the canner should be no more than 4 inches wider in diameter than the element on
which it is heated.
Follow these steps for successful boiling-water canning:
- Fill the canner halfway with water.
- Preheat water to 140° F for raw-packed foods and to 180° F for hot-packed foods.
- Load filled jars, fitted with lids, into the canner rack and use the handles to lower the rack into the water; or fill the canner, one jar at a time, with a jar lifter.
- Add more boiling water, if needed, so the water level is at least 1 inch above jar tops.
- Turn heat to its highest position until water boils vigorously.
- Set a timer for the minutes required for processing the food.
- Cover with the canner lid and lower the heat setting to maintain a gentle boil throughout the process schedule.
- Add more boiling water, if needed, to keep the water level above the jars.
- When jars have been boiled for the recommended time, turn off the heat and remove the canner lid.
- Using a jar lifter, remove the jars and place them on a towel, leaving at least 1-inch
spaces between the jars during cooling.
2c
The USDA does not recommend the use of the steam method or the open kettle method as neither of these processes are guaranteed to eliminate contaminants.
3
Sterilizing
There are at least two ways to sterilize jars:
- Boil them in water for 15 minutes
- Wash them in hot soapy water and then let them soak in bleached rinse water for at least two minutes. Use a quarter cup of bleach for every two gallons of water. Take the jars out of the bath and allow the bleach and water to evaporate for at least 15 minutes.
Boiling them can take a long time because it takes a lot of water to cover the jars completely, and it is difficult to get very many jars in even a very large pot. Then there is the problem of removing the boiling-hot jars from the pot. Because of this, it is often easier to use bleach.
Filling
You can either try to pour or ladle your food into the jars directly (though you risk making a big mess), or you can use a wide-mouth funnel. Most places that sell canning jars will also sell these funnels. The small end of the funnel fits nicely in the mouth of the jar, and the large end is wide enough to make pouring or ladling a lot easier.
Do not overfill the jars. Leave 2 cm or so of space at the top of the jar, though most recipes will actually specify the recommended headroom. If you run out of food before a jar is completely filled, it's OK to just leave it that way and seal it.
Sealing
Place the lid on top of the jar, making sure that the rubber seal on the underside of the lid comes in contact with the mouth of the jar. Then screw the threaded portion of the lid on over it. It only needs to be tight enough to hold the rubber seal to the mouth of the jar. The actual seal occurs because the air inside the jar shrinks as it cools, and this actually pulls the underside of the lid inward. Of course this only works if the food is hot when you pour it into the jar.
Testing Seals
After processing, remove jars from canner and place upright jars on a towel in a draft-free place. DO NOT retighten screw bands or check for seal while the jars are hot. Allow processed jars to cool undisturbed for 24 hours. After 24 hours, check the seals. Sealed lids curve downward and do not move when pressed.
4
Foods that are low in acid have a higher pH level and do not contain enough acid to prevent the growth of botulinum bacteria. These foods are processed at temperatures of 240 - 250 degrees F, attainable with pressure canners.
Low-acid foods include all fresh vegetables with the exception of tomatoes. Fruits and tomatoes are neutral- to high-acid foods.
5
Almost any fruit or vegetable can be canned or frozen, but there are a few exceptions. Summer squash and zucchini are better preserved by freezing than by canning. Salad greens and potatoes do not freeze very well and should be canned instead.
6
6a
Apple Juice
The USDA does not recommend the open kettle method as it does not ensure that the end product is uncontaminated. Rather, use the boiling water method.
- Quality
- Good quality apple juice is made from a blend of varieties. For best results, buy fresh juice from a local cider maker within 24 hours after it has been pressed.
- Procedure
- Refrigerate juice for 24 to 48 hours. Without mixing, carefully pour off clear liquid and discard sediment. Strain clear liquid through a paper coffee filter or double layers of damp cheesecloth. Heat quickly, stirring occasionally, until juice begins to boil. Fill immediately into sterile pint or quart jars (see page 1-9 to sterilize jars), or fill into clean half-gallon jars, leaving 1/4-inch headspace. Adjust lids and process as per the table below.
Using a boiling water canner | |||||
Jar size | 0-1000 ft | 1000-6000ft | Above 6000ft | ||
---|---|---|---|---|---|
Pints or quartz | 5 minutes | 10 minutes | 15 minutes | ||
Half gallons or gallons | 10 minutes | 15 minutes | 20 minutes |
6b
Hot packing
Hot-packing is the practice of heating freshly prepared food to boiling, simmering it 2 to 5 minutes, and promptly filling jars loosely with the boiled food. Whether food has been hot-packed or cold-packed, the juice, syrup, or water to be added to the foods should also be heated to boiling before adding it to the jars. This practice helps to remove air from food tissues, shrinks food, helps keep the food from floating in the jars, increases vacuum in sealed jars, and improves shelf life. Preshrinking food permits filling more food into each jar. Hot-packing is the best way to remove air and is the preferred pack style for foods processed in a boiling-water canner. At first, the color of hot-packed foods may appear no better than that of cold-packed foods, but within a short storage period, both color and flavor of hot-packed foods will be superior.
Cold packing
Cold-packing is the practice of filling jars tightly with freshly prepared, but unheated food. Such foods, especially fruit, will float in the jars. The entrapped air in and around the food may cause discoloration within 2 to 3 months of storage. Cold-packing is more suitable for vegetables processed in a pressure canner.
Berries
This procedure is suitable for blackberries, blueberries, currants, dewberries, elderberries, gooseberries, huckleberries, loganberries, mulberries, and raspberries.
- Syrup
- Syrup is a combination of sugar and water. The sugar volume ranges from 10% (for light syrup) to 50% (for heavy syrup).
- Quantity
- An average of 12 pounds is needed per canner load of 7 quarts; an average of 8 pounds is needed per canner load of 9 pints. A 24-quart crate weighs 36 pounds and yields 18 to 24 quarts—an average of 1-3/4 pounds per quart.
- Quality
- Choose ripe, sweet berries with uniform color.
- Procedure
- Wash 1 or 2 quarts of berries at a time. Drain, cap, and stem if necessary. For gooseberries, snip off heads and tails with scissors. Prepare and boil preferred syrup, if desired. Add 1/2 cup syrup, juice, or water to each clean jar.
- Hot pack
- For blueberries, currants, elderberries, gooseberries, and huckleberries. Heat berries in boiling water for 30 seconds and drain. Fill jars and cover with hot juice, leaving 1/2-inch headspace.
- Cold pack
- Fill jars with any of the raw berries, shaking down gently while filling. Cover with hot syrup, juice, or water, leaving 1/2-inch headspace.
Adjust lids and process following the procedure outlined in requirement 2b.
6c
Beans or Peas—Shelled, Dried (Hot pack)
- Quantity
- An average of 5 pounds is needed per canner load of 7 quarts; an average of 3-1/4 pounds is needed per canner load of 9 pints—an average of 3/4 pounds per quart.
- Quality
- Select mature, dry seeds. Sort out and discard discolored seeds.
- Procedure
- Place dried beans or peas in a large pot and cover with water. Soak 12 to 18 hours in a cool place. Drain water. To quickly hydrate beans, you may cover sorted and washed beans with boiling water in a saucepan. Boil 2 minutes, remove from heat, soak 1 hour and drain. Cover beans soaked by either method with fresh water and boil 30 minutes. Add 1/2 teaspoon of salt per pint or 1 teaspoon per quart to the jar, if desired. Fill jars with beans or peas and cooking water, leaving 1-inch headspace. Adjust lids and hot pack using the processing times and pressures in the tables below.
Using a dial-gauge pressure canner | |||||
Jar size | Processing time | 0-2000 ft | 2000-4000ft | 4000-6000ft | 6000-8000ft |
---|---|---|---|---|---|
Pints | 75 minutes | 11 pounds | 12 pounds | 13 pounds | 14 pounds |
Quarts | 90 minutes | 11 pounds | 12 pounds | 13 pounds | 14 pounds |
Using a weighted-gauge pressure canner | |||||
Jar size | Processing time | 0-1000 ft | Above 1000ft | ||
---|---|---|---|---|---|
Pints | 75 minutes | 10 pounds | 15 pounds | ||
Quarts | 90 minutes | 10 pounds | 15 pounds |
Fresh Beans (cold pack)
- Quantity
- An average of 28 pounds is needed per canner load of 7 quarts; an average of 18 pounds is needed per canner load of 9 pints. A bushel weighs 32 pounds and yields 6 to 10 quarts—an average of 4 pounds per quart.
- Quality
- Select well-filled pods with green seeds. Discard insect-damaged and diseased seeds. Procedure: Shell beans and wash thoroughly.
- Cold pack
- Fill jars with raw beans. Do not press or shake down.
- Small beans—leave 1-inch of headspace for pints and 1-1/2 inches for quarts.
- Large beans—leave 1-inch of headspace for pints and 1-1/4 inches for quarts.
Add 1 teaspoon of salt per quart to the jar, if desired. Add boiling water, leaving the same headspaces listed above. Adjust lids and process as per the tables below.
Using a dial-gauge pressure canner | |||||
Jar size | Processing time | 0-2000 ft | 2000-4000ft | 4000-6000ft | 6000-8000ft |
---|---|---|---|---|---|
Pints | 40 minutes | 11 pounds | 12 pounds | 13 pounds | 14 pounds |
Quarts | 50 minutes | 11 pounds | 12 pounds | 13 pounds | 14 pounds |
Using a weighted-gauge pressure canner | |||||
Jar size | Processing time | 0-1000 ft | Above 1000ft | ||
---|---|---|---|---|---|
Pints | 40 minutes | 10 pounds | 15 pounds | ||
Quarts | 50 minutes | 10 pounds | 15 pounds |
6d
You can make jelly or jam from almost any fruit you like. Strawberry, blackberry, raspberry, grape, and plum are all excellent choices, but you can also use a variety of wild fruits as well, including rose hip, gooseberry, autumn olive, and elderberry. We present a recipe for plum jam here, but an almost identical recipe for rose hip jam can be found in requirement 4 of the Herbs honor.
Template:Adventist Youth Honors Answer Book/Recipe
References