Canning Chile Peppers

Most of this information has come from sources in the USA, where canning is very popular.

Because chiles are naturally low in acid, canning them requires special precautions that differ from those followed when canning high-acid fruits. Growth of micro-organisms particularly must be avoided. Some bacteria cause food spoilage, while others produce toxins that cause illness or death. For example, Clostridium botulinum is a harmless bacteria in air. In little or no acid, an air-free canning jar, and temperatures between 40degF and 120degF, this bacteria grows and produces a deadly toxin that can cause serious damage to the central nervous system or death when eaten in even minute amounts.

Pressure processing is the only safe way to can chiles and other non-acid foods. Boiling water produces steam. Steam under pressure raises the temperature much higher than it normally would be without pressure. To prevent botulism, the internal temperature of canned chiles and other non-acid foods must reach 240degF. To prevent the risk of botulism, chiles and other low-acid and tomato foods not canned according to the 1994 USDA recommendations in this guide should be boiled even if no signs of spoilage are detected. Boil food for a full 10 minutes at altitudes below 1,000 feet. Add an additional minute of boiling time for each 1,000 feet of elevation. Boiling destroys botulism toxin. If in doubt, always boil foods before tasting.

Selecting your chile peppers

Select chiles that are mature, heavy for their size, smooth and symmetrical, bright green in colour, fresh, and crisp. You should avoid misshapen pods, shriveled skin, mould, soft spots, and those pods with bruises. It takes approximately 9 pounds of fresh chiles to make 9 pints of canned chiles.

Preparing your chile peppers

The tough outer skin must be removed from chiles. Blistering the skin by one of the following methods makes removal easy.

Handling pungent chiles can burn hands and eyes.

Protect hands with a thin layer of solid fat or wear rubber gloves.

Keep hands away from eyes while working with chiles.

Wash hands before and after going to the bathroom and before touching other people.

Wash and dry your chiles. With a knife, make a small slit in the side to allow steam to escape. Be sure heat source is very hot. Turn chiles frequently to prevent scorching and to ensure even blistering. Remove from heat and spread the chiles on a flat surface in a single layer to let them cool down before peeling. For easier peeling, place in a pan and cover with a damp towel for a few minutes.

The following are three heat-source methods for blistering chiles:

Oven or broiler method: Place chiles in a hot oven or broiler 400-450degF for 6-8 minutes until skin blisters so that it can be pulled away form the flesh.

Range top method: Place chiles on a hot electric or gas burner after covering burner with a layer of heavy wire mesh.

Outdoor grill method: Place chiles on a charcoal grill about 5-6 inches above glowing coals.

If chiles are not processed within two hours after blistering, place them in shallow containers in the refrigerator to prevent spoiling. This applies to both purchased, roasted chiles as well as those roasted at home. If desired, add 1/4 teaspoon of salt per half-pint, or 1/2 teaspoon salt per pint. Salt may be omitted, as it's used only for flavour. For best results, do not use salt substitutes for canning because heat causes some substitutes to become bitter or develop a metallic taste. Instead, add the salt substitutes just before serving.

General canning procedures

Use regular and wide-mouth Mason jars with self-sealing lids held in place by screw-on metal bands. The bands hold the lids in place during the processing and cooling periods. Mason jars are made from tempered glass to resist high temperatures. Only half-pint and pint jars should be used for canning green chiles.

Inspect jars carefully for cracks or chips; discard faulty ones. Wash jars in hot, soapy water and rinse thoroughly or in the dishwasher. Keep jars hot in the dishwasher, a sink of hot water, or a warm oven until they are filled. Check metal screw bands for signs of rust or dents. Discard badly corroded or dented bands. Use only new lids and follow manufacturer's directions for preparing lids for canning.

Remove peels, stems, and seeds from chiles. Chiles can be cut in pieces or left whole. Pack chiles loosely and add boiling water. Leave a 1-inch headspace. Using a rubber or plastic spatula or knife that won't nick or scratch the jar, slice between the chiles and the jar to ease out trapped air bubbles.

Use a clean, damp cloth or paper towel to wipe the rim and threads of each jar. Put on a new lid with a screw-on metal band to hold it in place; tighten comfortably. Process using a pressure canner.

Dial gauges on pressure canners should be checked annually to make sure they are accurate.

Want to find out more about what type of jar to use? See the Canning Center!

Pressure canning procedures

Put 2-3 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 the petcock. Heat at the highest setting until steam flows from the vent port or petcock.
Maintain high heat setting, exhaust steam 10 minutes, and then place weight on vent port or close petcock. The canner will pressurise during the next 3-5 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. Gauges on "Presto" canners 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 de-pressurise. Do not force-cool the canner. Force cooling may result in food spoilage. Cooling the canner with cold running water or opening the vent port before the canner is fully de-pressurised will cause loss of liquid from jars and seal failures. Force-cooling also can warp the canner lid of older model canners, causing steam leaks. De-pressurisation of older models should be timed. Standard-size heavy-walled canners require about 30 minutes when loaded with pints. Newer thin-walled canners cool more rapidly and are equipped with vent locks. These canners are de-pressurised when their vent lock piston drops to a normal position.
After the canner is de-pressurised, 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 the steam does not burn your face.
Remove jars with a lifter, and place on towel or cooling rack, if desired.

Processing times in a "boiling water canner"
Food	Pack	Jar size	0-1000 ft	1001-3000 ft	3001-6000 ft
Chile Salsa	Hot	Pints	15 mins	20 mins	20 mins
Tomatillo Green Salsa	Hot	Pints	15 mins	20 mins	20 mins
Green Chile Salsa	Hot	Pints	15 mins	20 mins	20 mins

Storing canned food

Clean the outsides of the sealed and cooled jars. Label them with the date and the contents and then store them in a cool (50-70degF), dark, dry place away from the sun, bright light, or dampness.