Jars, rings and lids: Use proper canning jars, which can be reused each year if there are no nicks or cracks. Used mayo bottles, etc., aren't made to take the heat and pressure. The metal lids are one-time use. The screw-on rings can be reused, but not if they're dented or rusted.

"If they're rusted, they won't apply uniform pressure to get a good seal," said Brock.

Fresh produce: The fresher the produce, the better the results, said Jeanne Pulliam, another award-winning home canner. "When people use old fruit to make jam, they find out it doesn't set up because the properties of the fruit have changed," Pulliam said.

Some fruits are easier to can than others. For instance, pears are labor-intensive to peel. If you're doing peaches, you will save time and frustration by using a "freestone" variety of peaches, so the pit comes out easier than a "clingstone" variety, said Hunsaker.

When slicing the fruit or vegetables, make the pieces uniform in size, said Pulliam. This allows uniform heat penetration during processing.

If you're doing a "hot-pack" recipe, where you bring the food to a boil, it's not OK to let it cool before processing. The processing times are based on the food being hot in the beginning.

Smooth-top ranges: Most smooth-top ranges have a thermostatic control that shuts off when it's too hot or weighed down with lots of water and bottles of fruit. The heat won't stay consistent for processing, and some tops will crack. Hunsaker said a few models allow one burner for canning, but shoppers should investigate to make sure.

If you buy a smooth-top range, save your old range in the basement, or invest in a camp stove. (As a bonus, you can do your canning outside and avoid heating up the kitchen.)

Sugarless canning: In the case of canned fruits, sugar is not a preservative, although it keeps the color longer, said Hunsaker. She prefers using white grape juice or orange or pineapple juice, which gives more flavor to the fruit.

When making jams and jellies, though, too little sugar prevents gelling and may allow yeasts and molds to grow. So use an approved recipe for these, or a special "low-sugar" pectin.

TOMATO/GREEN CHILE SALSA

3 cups peeled, cored, chopped tomatoes
3 cups seeded, chopped long green chiles
3/4 cup chopped onions
1 jalapeno, seeded, finely chopped
6 cloves garlic, finely chopped
1 1/2 cups vinegar
1/2 teaspoon ground cumin
2 teaspoon oregano leaves
1 1/2 teaspoon salt

Combine all ingredients in a large saucepan and heat, stirring frequently, until mixture boils. Reduce heat and simmer for 20 minutes, stirring occasionally.