Basic Canning Tips For Complete Newbies

Automated PDF to Text preview page 4 to 6:

Acidic foods have pH values below 4.6. These foods include pickles, most fruits, and jams and jellies made from fruit. (In pickling, the acid level is increased by adding lemon juice, citric acid, or vinegar.) Acidic foods contain enough acidity either to stop the growth of botulinum bacteria or destroy the bacteria more rapidly when heated. Acidic foods may be safely canned in a boiling water canner. Low-acid foods have pH values higher than 4.6. They do not contain enough acid to prevent the growth of botulinum bacteria. These foods are processed at temperatures of 240 degrees F to 250 degrees F, attainable with pressure canners operated at 10 to 15 pounds per square inch (psi) of pressure. The exact time depends on the kind of food being canned, the way it is packed in jars, and the size of jars. When you mix low-acid and high-acid foods, assume the mixture remains low-acid. Although tomatoes used to be considered an acidic food, some are now known to have pH values slightly above 4.6, which means they ar
e low acid. To safely can them as acidic foods in a boiling water canner, you must add lemon juice or citric acid. Adjust for Altitude to Ensure a Safe Product When canning, you must know your altitude--even in Ohio. Do not use process times recommended for canning food at sea level if you live at an altitude above 1,000 feet. Water boils at lower temperatures as altitude increases. Lower boiling temperatures are less effective for killing bacteria. You must increase either the process time or canner pressure to make up for lower boiling temperatures. Use publications based on United States Department of Agriculture (USDA) approved guidelines to select the proper processing time and canner pressures for your altitude. Using Boiling Water Canners Most boiling water canners are made of aluminum or porcelain-covered steel. They have removable racks and fitted lids. The canner must be deep enough so that at least one inch of briskly boiling water will be over the tops of jars during processing. Some boiling wate
r canners do not have flat bottoms. A flat bottom is more energy efficient on an electric range. A ridged bottom can be used more efficiently 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. If you have a ceramic top range, check the manufacturer's instructions before you begin to can. Steps for Successful Boiling Water Canning 1. Fill the canner halfway with water. 2. Preheat the water to 140 degrees F for raw-packed foods and to 180 degrees 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 hot water, if needed, so the water level is at least 1 inch above jar tops.Cover with the canner lid. 5. Turn heat to its highest position until the water boils vigorously. 6. Set a timer for the minutes required for processing the food. 7. 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 processed 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 of space between the jars during cooling. Using Pressure Canners Newer models of pressure canners have been extensively redesigned. Those made before the 1970s were heavy-walled kettles with clamp-on or turn-on lids. They were fitted with a d
ial gauge, a vent port in the form of a petcock or counterweight, and a safety fuse. Modern pressure canners are lightweight, thin-walled kettles; most have turn-on lids. They have a removable jar rack, gasket, dial or weighted gauge, and automatic vent/cover lock, a vent port (steam vent) to be closed with a counter weight or weighted gauge, and a safety fuse. A pressure canner must be used for all low-acid foods. Two serious canning errors can occur when pressure processing. 1. Internal canner pressures are lower at higher altitudes. Canners must be operated at increased pressures as the altitude increases. 2. Air trapped in a canner lowers the temperature obtained at 5, 10, or 15 psi and results in underprocessing. To be safe, vent all pressure canners 10 minutes before they are pressurized. Dial gauges should be checked for accuracy each year before use. Check with your local Extension Office for information on this service. If your gauge reads high or low by more than 1 pound at 5, 10, or 15 psi, replac
e, or have it repaired. Clean lid gaskets and other parts according to the manufacturer's directions. Use only canners approved by the Underwriter's Laboratory (UL). 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. While maintaining high heat setting, vent the canner by allowing steam to escape for 10 minutes, 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 or large pressure variations during processing may cause unnecessary liquid losses from jars. One type of weighted gauge should jiggle 2 or 3 times per minute, while another type should rock slowly throughout the process--check the manufacturer's directions.
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 will cause liquid loss from the jars and may result in food spoilage. Forced cooling may warp the canner lid and cause seal failure. Depressurization of older canner models should be timed. Standard size, heavy-walled canners require about 30 minutes when loaded with pints and 45 minutes when loaded with quarts. Newer thin-walled canners cool more rapidly and are equipped with vent/cover 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 two 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 away from drafts, leaving at least 1 inch between jars during cooling. Stay Clear o
f Unsafe Canning Methods Never open-kettle can or process jars of food in conventional ovens, microwave ovens, or dishwashers. These practices do not prevent all risks of spoilage. Steam canners and electric water bath canners are not recommended because safe processing times have not been adequately researched. Using boiling-water canner processing times with either of these canners may result in spoilage. So-called "canning powders" are useless as preservatives and do not replace the need for proper heat processing.