Unlike the weighted gauge that requires no service, you must check this control for accuracy each season or at least once every year of use. To obtain service, refer to your owner’s manual for service locations, check with the store where you purchased the canner, or contact your local cooperative extension services (see Chapter 22).
If your annual service shows that your dial gauge is off by 5 or more pounds, replace the gauge. An inaccurate reading may not produce the temperature required to kill all microorganisms. You can have your canner checked for a nominal fee, if not free, at your local hardware store or county extension office.
Vent tube, pipe vent, or petcock
Whatever the name of this feature — vent tube, pipe vent, or petcock — the function is the same (see Figure 9-5). These terms refer to an opening in the pressure-canner cover for emitting steam. Sometimes the weighted gauge sits on the vent tube.
Figure 9-5: A vent tube.
To work properly, the vent tube opening cannot be obstructed with food or other matter. Obstructions restrict the optimum pressure and temperature required for your recipe. To check the vent for obstructions, hold it up to the light. If the vent appears to be clogged, insert a piece of wire (or other item suggested in your owner’s manual) into the tube. Rinse the vent with hot water. Repeat the procedure if you still see an obstruction.
Overpressure plug
An overpressure plug (see Figure 9-6) releases (pops up) if too much pressure exists in your pressure canner due to a blocked vent tube. The overpressure plug is a safety feature that’s solely for your protection. If you follow the instruction manual for your pressure-canner operation, chances are this plug will never be used.
Figure 9-6: An over-pressure plug.
Rack
Your pressure canner should come with a rack. (If the rack is missing, contact the store where you made your purchase.) The perfect rack lies flat in the bottom of your canner and has lots of holes and openings that allow steam to circulate around your filled jars. Figure 9-7 is an example of a canner rack.
Figure 9-7: A rack for holding jars in the bottom of your pressure canner.
Make sure your rack is stable when you place it in the bottom of the canner. A stable rack holds jars in place, thus preventing the jars from tipping, touching other jars, or touching the sides of the canner.
A-Canning You Will Go: Instructions for Successful Pressure Canning
In order to ensure a processed product of high quality, free from microorganisms, be sure to follow each step in this section. Don’t omit or modify any part. You may spend a bit more time canning low-acid foods with a pressure canner than you would canning high-acid foods in a water-bath canner, but the end result is worth the extra effort.
In this section, you begin your journey of pressure-canning low-acid foods. Avoid any temptation to omit any step or portion of any step in the process. Each step is important to produce safe, home-canned foods.
If you’ve never used a pressure canner before, do a trial run with no jars: Heat up the canner and go through the steps of pressurizing and depressurizing to familiarize yourself with the sounds the pressure canner makes as it builds and then releases pressure. You’ll hear the steam escaping, the weight gauge shaking, and the ticking of the canner as it heats and cools; if you don’t know what to expect, you could misinterpret these noises as scary or wrong.
Step 1: Gearing up
At least a couple of weeks before you want to use it, check your pressure canner and replace any gasket or missing part, have a dial gauge checked professionally, and replace a missing manual. Also count your jars and two-piece caps and examine the jars for nicks or chips, the screw bands for proper fit and corrosion, and the new lids for imperfections and scratches. It’s also a good idea to select your recipe, and inventory your pantry for any nonperishable ingredients, adding any needed items to your shopping list. Your goal is to have all the supplies you need and your pressure canner in good working order on the day you’re ready to can.
Preparing your pressure canner before the actual canning season means you will not find the store out of supplies and the extension agent too busy to check your gauge in time to begin canning when the produce is ripe.
On the actual canning day, get your tools ready by following these steps:
1. Assemble your prechecked equipment and utensils.
In addition to your pressure canner and the standard canning supplies (jars with two-piece lids), other items can make your canning easier: things like a food scale, extra pans for cooking your veggies and keeping a water reserve on hand, a wide-mouth funnel, and so on. Head to Chapter 2 for a list of canning supplies.
2. Wash your jars and screw bands in warm, soapy water, rinsing well to remove any soap residue.
Double-check for nicks and dents and discard any damaged items.
3. Place your clean jars and lids in a kettle of hot — not boiling — water until you’re ready to fill them.
Never boil the lids because the sealant material may be damaged and won’t produce a safe vacuum seal.
4. Ready your canner by filling it with 2 to 3 inches of water and heating the water.
Always read the manufacturer’s instructions for your pressure canner and follow them to the letter.
Also, assemble the other canning items you need. You can find a complete list in Chapter 2.
Step 2: Preparing your food
Always start with food of the highest, freshest quality. Food that’s spoiled or bruised doesn’t improve in quality during the pressure-canning process! To prepare your food for pressure canning, follow these steps:
1. Wash all food prior to packing it in the jars or precooking it.
For detailed instructions on washing your food, refer to Chapter 3.
2. Thoroughly cut away all evidence of spoilage or discard any inferior products.
3. Prepare the food by precisely following your recipe.
Some recipes call for you to fill your jars with raw food; others may want you to precook the food. If you’re precooking your low-acid food before filling your jars, don’t discard the cooking liquid; use this liquid for filling your jars.
Work in manageable batches. To determine just what a “manageable batch” is, consider how much food fills one canner load at a time. Most recipes are geared for manageable batches, but if you’re in doubt, check the yield for the recipe.
Step 3: Filling your jars
Always place your product into hot jars (you keep them hot by leaving them in a kettle of hot water, as explained in the earlier section “Step 1: Gearing up.”) To fill your jars, follow these steps:
1. Remove a jar from the kettle and pack the food into the jar so that the food is snug, yet loose enough for liquid to circulate into the open spaces.
2. Ladle boiling water (or the liquid from precooking the vegetables) into the jars, leaving the amount of headspace stated in your recipe.
If you’re adding cooking liquid, divide the cooking liquid evenly among the jars and finish filling the jars with boiling water, if necessary. That way, if you run short of the cooking liquid, you won’t have one jar filled with only boiling water.
3. Release any air bubbles with a nonmetallic spatula or a tool to free bubbles.
If the headspace drops, add additional food and liquid to the jar.
4. Wipe the jar rims with a clean, damp cloth.
Have a few rags handy to be sure you’re using a clean one every time.
5. Place a lid on the jar (seal side down) and secure the lid in place with a screw band.
Hand-tighten the band without overtightening it.
Always work quickly, stopping for nothing. Time is of the essence! Your hot foods need to remain hot, your lids seal best if placed on the jars while hot, and your food needs to be processed as quickly as possible to preserve the most flavor and quality.
Step 4: Placing the jars in the canner
Place your filled and closed jars carefully on the rack in the
pressure canner, making sure you have the recommended amount of simmering water in the bottom of the canner. Don’t crowd the jars or place more jars in the canner than is recommended for your size of pressure canner. Place them so that they’re stable, won’t tip, and don’t touch each other or the side of the canner.
If your recipe makes more jars than your canner can hold, only fill enough jars for one canner load and do the rest in the next batch. Do not fill all the jars and leave a few waiting for the next canner load.
Unlike water-bath canning (see Chapter 4), you can process a second layer of pint or half-pint jars at the same time as long as your canner accommodates the height of the two layers. To build the second layer, place a second rack on top of the first layer of jars. Stagger the second layer of jars so they aren’t directly above the bottom layer. This permits proper air circulation for achieving the proper pressure and temperature. After you have a few simple canning sessions successfully under your belt, try this technique to save a little time.
Step 5: Closing and locking the canner
For optimum performance, steam must be allowed to steadily escape from the canner for a specified period. This process is called exhaustion. Properly closing and locking your pressure canner ensure that exhaustion can take place. Closely follow your owner’s manual when closing and locking the pressure canner. (If not sealed properly, the canner won’t build pressure and/or hot water will spit out.)
Step 6: Processing your filled jars
Once your canner lid is locked on, you’re ready to beginning processing your filled jars. Follow these steps:
1. Allow a steady stream of steam to escape from the pressure canner for 10 minutes or the time recommended in your manual.
2. Close the vent, bringing the pressure to the amount specified in your recipe.
If you live in higher altitudes, see the section “Pressure Canning at Higher Altitudes” for information on how to adjust the pounds of pressure used during processing.
Processing time starts when your canner reaches the required pressure. The pressure must remain constant for the entire processing time. If your pressure drops at any time during processing, so will your temperature. To remedy this problem, return the pressure to the specified amount by increasing the heat. After your pressure has been regained, start your processing time from the beginning.
3. After the processing time has passed, turn the heat off and allow the pressure to return to 0.
Allowing the pressure to return to 0 may take as long as 30 minutes. Don’t disturb the canner; jars that are upset may not seal properly.
Step 7: Releasing the pressure after processing
Approximately 10 minutes after the pressure returns to 0, or at the time stated in the manual, remove the lid, opening the cover away from you and allowing the steam to flow away from you.
We can’t emphasize enough the importance of following the instructions in your owner’s manual, step by step, for releasing the pressure in the canner after your processing time is concluded. There’s no quick-release method for a pressure canner as there is for a pressure cooker. Don’t confuse the two!
Running water over your pressure canner to reduce the pressure is a definite no-no. The sudden change in temperature can cause the jars to burst.
Step 8: Removing and cooling the jars
Ten minutes after you release the pressure (Step 7), remove the jars from the pressure canner with a jar lifter. Place them on a clean towel, away from drafts with 1 to 2 inches of space around the jars.
The jars may take as long as 24 hours to completely cool. Don’t be tempted to play with the lids or adjust the bands.
As your jars cool, you’ll hear a popping noise coming from them, indicating a vacuum seal. You will soon learn to look forward to these tiny pings and dings. My children (Amy’s) often give a shout each time they hear one. This canning music means you have successfully saved your summer bounty.
Step 9: Testing the seal and storing your bounty
The final pressure-canning step is to test the seals on your completely cooled jars: Push on the center of the lid. If the lid feels solid and doesn’t indent, you’ve produced a successful seal. If the lid depresses when applying pressure, this jar isn’t sealed. Refrigerate any unsealed jars immediately, using the contents within two weeks or the period stated in your recipe.
To store jars, do the following:
1. Remove the screw bands of the sealed jars.
2. Remove any residue by washing the jars, lids, and bands in hot, soapy water; then dry them.
3. Label your jars with the content and date of processing.
4. Store the jars without the screw bands, in a cool, dark, dry place.
Disposing of Spoiled Products
Although you may follow all the steps and procedures for pressure canning low-acid foods (see the preceding section), you still have a chance for spoilage. Knowing the signs to look for is part of the food-preservation process.
Here are some visual signs that may indicate a spoiled product:
A bulging lid or a broken seal
A lid that shows signs of corrosion
Food that has oozed or seeped under the lid
Gassiness, indicated by tiny bubbles moving upward in the jar
Food that looks mushy, moldy, or cloudy
Food that gives off an unpleasant or disagreeable odor when the jar is opened
Spurting liquid from the jar when the seal is broken
Storing your sealed jars without the bands allows you to see any signs of food seepage that indicates a potentially spoiled product.
As discussed in Chapter 3, botulism poisoning can be fatal. Because botulism spores have no odor and can’t be seen, you can’t always tell which jars are tainted. If you suspect that a jar of food is spoiled, never, never, never taste it. Instead, dispose of the food responsibly.
When you need to dispose of spoiled low-acid foods, use one of the two disposal methods described in the following sections. The first method is for sealed jars and second is for jars with broken seals.
If your jar is still sealed
If the jar has the seal intact, you can simply place your container in a garbage bag, tie it tightly, and discard it in the trash. This keeps the product from coming in contact with any human or animal and eliminates the transfer of bacteria. Be sure to thoroughly wash your hands and any surface that may have come in contact with spoiled food or its juices.
If your jar has a broken seal
If you see signs that the seal is broken or not tight, place the jar, the lid, the screw band, and the contents of the jar in a deep cooking pot. Cover the items with 1 to 2 inches of water, taking care not to splash any of the contents outside of the pot (this can cause cross-contamination with other foods in your household).
Cover the pot with a tight-fitting cover. Bring the contents to a boil. Keep the contents boiling for 30 minutes. Turn off the heat and allow the contents to cool while remaining covered. Discard the contents in a sealed container in the trash or bury them deeply in the soil.
Never pour the contents into a water source, a sink or garbage disposal, or down the toilet, because the contents may come into contact with humans or animals through a water-reclamation process.
Using a solution made up of one part household chlorine bleach to four parts tepid (lukewarm) water, thoroughly wash all equipment, working surfaces, clothing, and body parts that may have come in contact with the jar or spoiled food. You may also add dishwashing soap. Dispose of the jar, the lid and screw band, and any sponges or dishcloths used in any phase of this process by wrapping the items in a trash bag, sealing the bag, and placing it in the trash.
Pressure Canning at Higher Altitudes
If you’re canning at an elevation higher than 1,000 feet above sea level, adjust the pounds of pressure used during processing, according to Table 9-1. Your pressure-canner processing time will remain the same.
Table 9-1 High-Altitude Processing Times for Pres
sure Canning
Altitude
Process at This Pressure
2,000–3,000
11 1/2 pounds
3,000–4,000
12 pounds
4,000–5,000
12 1/2 pounds
5,000–6,000
13 pounds
6,000–7,000
13 1/2 pounds
Canning and Preserving For Dummies Page 15