Especialidades JA/Conservación de alimentos/Respuestas

Conservación de alimentos

Autoridad de aprobación:
Categoría:
Nivel de destreza:
Año de introducción:

Contenido

1

Definir los siguientes:

1a

Botulismo

1b

Olla de presión

1c

Baño de agua hirviendo

1d

Baño de vapor o baño maría

1e

Olla abierta

1f

La pectina

1g

Empaque caliente

1h

Empaque frío

1i

Esterilizar

1j

Escaldar

1k

Jalea

1l

Dulce

1m

Mermelada

1n

Encurtidos

2

Hacer una lista de los equipos utilizados en los siguientes métodos de enlatado:

2a

Presión

Pressure canners for use in the home have been extensively redesigned in recent years. Models made before the 1970's were heavy-walled kettles with clamp-on or turn-on lids. They were fitted with a dial gauge, a vent port in the form of a petcock or counterweight, and a safety fuse. Modern pressure canners are lightweight, thinwalled kettles; most have turn-on lids. They have a jar rack, gasket, dial or weighted gauge, an automatic vent/cover lock, a vent port (steam vent) to be closed with a counterweight or weighted gauge, and a safety fuse.

Pressure does not destroy microorganisms, but high temperatures applied for an adequate period of time do kill microorganisms. The success of destroying all microorganisms capable of growing in canned food is based on the temperature obtained in pure steam, free of air, at sea level. At sea level, a canner operated at a gauge pressure of 10.5 lbs provides an internal temperature of 240° F.

Two serious errors in temperatures obtained in pressure canners occur because:

1. Internal canner temperatures are lower at higher altitudes. To correct this error, canners must be operated at the increased pressures specified in this publication for appropriate altitude ranges.
2. Air trapped in a canner lowers the temperature obtained at 5, 10, or 15 pounds of pressure and results in under processing. The highest volume of air trapped in a canner occurs in processing raw-packed foods in dial-gauge canners. These canners do not vent air during processing. To be safe, all types of pressure canners must be vented 10 minutes before they are pressurized.

To vent a canner, leave the vent port uncovered on newer models or manually open petcocks on some older models. Heating the filled canner with its lid locked into place boils water and generates steam that escapes through the petcock or vent port. When steam first escapes, set a timer for 10 minutes. After venting 10 minutes, close the petcock or place the counterweight or weighted gauge over the vent port to pressurize the canner.

Weighted-gauge models exhaust tiny amounts of air and steam each time their gauge rocks or jiggles during processing. They control pressure precisely and need neither watching during processing nor checking for accuracy. The sound of the weight rocking or jiggling indicates that the canner is maintaining the recommended pressure. The single disadvantage of weighted-gauge canners is that they cannot correct precisely for higher altitudes. At altitudes above 1,000 feet, they must be operated at canner pressures of 10 instead of 5, or 15 instead of 10, PSI.

Check dial gauges for accuracy before use each year and replace if they read high by more than 1 pound at 5, 10, or 15 pounds of pressure. Low readings cause over-processing and may indicate that the accuracy of the gauge is unpredictable. Gauges may be checked at most county Cooperative Extension offices.

Handle canner lid gaskets carefully and clean them according to the manufacturer's directions. Nicked or dried gaskets will allow steam leaks during pressurization of canners. Keep gaskets clean between uses. Gaskets on older model canners may require a light coat of vegetable oil once per year. Gaskets on newer model canners are prelubricated and do not benefit from oiling. Check your canner's instructions if there is doubt that the particular gasket you use has been pre-lubricated.

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:

1. 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.
2. Leave weight off vent port or open petcock. Heat at the highest setting until steam flows from the petcock or vent port.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. Remove jars with a lifter, and place on towel or cooling rack, if desired.

2b

Baño de agua hirviendo

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:

1. Fill the canner halfway with water.
2. Preheat water to 140° F for raw-packed foods and to 180° F for hot-packed foods.
3. 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.
4. Add more boiling water, if needed, so the water level is at least 1 inch above jar tops.
5. Turn heat to its highest position until water boils vigorously.
6. Set a timer for the minutes required for processing the food.
7. Cover with the canner lid and lower the heat setting to maintain a gentle boil throughout the process schedule.
8. Add more boiling water, if needed, to keep the water level above the jars.
9. When jars have been boiled for the recommended time, turn off the heat and remove the canner lid.
10. 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

Vapor

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

Dar las instrucciones de esterilización, llenado, sellado y pruebas de los sellos en los frascos.

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

¿Cuándo los alimentos deben ser procesados con vapor a presión?

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

Hacer una lista de los tipos de verduras y frutas que son excelentes para en enlatado en lugar de la congregación o la deshidratación.

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

Conservar las siguientes elementos:

6a

Un jugo de frutas mediante el método de olla abierta.

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

Dos tipos de frutas utilizando el método de baño de agua hirviendo, uno en empacado caliente y otro en empacado frío.

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

Dos tipos de hortalizas, utilizando el método de enlatado de presión, uno en empacado caliente y otro en empacado frío.

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

Una jalea o mermelada.

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.

References

• USDA Complete Guide to Home Canning