Many cooks have a bit of trepidation about canning. And with good cause — canned low-acid foods such as vegetables, meats and some tomatoes can harbor harmful organisms if not processed properly. But high-acid foods, including most fruits, pose little risk.
Almost all bacteria, yeast and molds will die when exposed to temperatures between 175 degrees and 210 degrees. The exception is botulinum toxin. Food-borne botulism is rare, but it can be fatal. Which leads us back to the fear that shrouds home canning. While botulinum toxin can survive high heat and little oxygen, it cannot grow below a pH of 4.6.
The good news is most fruits used for jam and jelly making are high acid.
Jordan Champagne's book It Starts With Fruit, includes a handy chart that lists the pH of common fruits as well as pectin levels. We'll get to pectin in a minute.
Lemons, limes, cranberries and pomegranates sit at the most acidic end of the scale with a pH of 2.0-3.0; next are apples, stone fruits, bush and bramble berries, rhubarb, oranges, grapefruit and quinces with pH of 3.0-4.0; then we enter the gray area of bananas, pineapples, papayas, some figs, pears, some tomatoes and some grapes which fall between 4.0-4.6. Some tomatoes and some figs, along with Asian pears and persimmons fall in the 4.6-5.0 range. Melons, mangoes and dates are even less acidic. Water, at 7.0, is the neutral point.
Vegetables, peppers, legumes, herbs, mushrooms, olives, grains, meat and dairy fall between 4.6 and 7.5, making them unsuitable for boiling water bath canning. These foods must be pressure canned.
But jam is virtually risk-free. By starting with high acid fruit, adding sugar (a natural preservative), and sometimes lemon juice (more acid) and cooking the mixture to the gelling stage — 220 degrees — and then refrigerating or canning the jam in a boiling water bath canner there's very little that can go wrong.
Pectin is naturally present in almost all fruits to varying degrees. Under-ripe fruit has more pectin than ripe fruit, and some fruits such as apples, quince, cranberries, grapes and lemon are quite high in pectin. At the lower end are peaches, blueberries, figs, pears and strawberries.
Most jam recipes call for some pectin, but cooked jams do not require the addition of pectin. They simply require careful cooking to ensure proper gelling. However, low-sugar and freezer (uncooked) jams, do require the addition of pectin.
Commercial pectins are not interchangeable, but the fruit used in most recipes is. Be sure to use the specific kind of pectin called for in the recipe.
For example, we made Raspberry-Rose Freezer Jam which is no-cook and made with freezer pectin. While this recipe will not work with regular pectin, you could swap the raspberries for blueberries, strawberries, grapes or even plums or peaches (add a little lemon juice) and the recipe will still work.
For further reading:
■ The New Homemade Kitchen: 250 Recipes and Ideas for Reinventing the Art of Preserving, Canning, Fermenting, Dehydrating and More by Joseph Shuldiner
■ It Starts With Fruit: Simple Techniques and Delicious Recipes for Jams, Marmalades, Preserves by Jordan Champagne
■ Preservation Society Home Preserves: 100 Modern Recipes by Camilla Wynne
■ Ball Canning Back to Basics: A Foolproof Guide to Canning Jams, Jellies, Pickles and More by Ball Canning Test Kitchen
■ Preserving the Season: 90 Delicious Recipes for Jams, Jellies, Preserves, Chutneys, Pickles, Curds, Condiments, Canning & Dishes Using Them by Mary Tregellas. (I should note this book does not follow modern food safety practices. However, it does contain some useful information.)
For detailed, step-by-step instructions on preparing a boiling water canner, canning jars and lids, click here.
With the exception of the apricot jam, all of the following recipes are prepared using fresh fruit. We used Ball brand powdered pectin in the following recipes.
Apricot-Earl Grey Jam
2 ¼ cups dried Turkish apricots, halved or quartered
Juice of 1 lemon
1 ¼ cups brewed Earl Grey tea
1 cup granulated sugar
Place the apricots, lemon juice, Earl Grey tea and sugar in a medium saucepan. Bring to a boil, stir, then turn off the heat and cover with a lid. Let cool to room temperature.
Pour into a food processor and puree until smooth. Return mixture to heat and cook until mixture reaches a full, rolling boil that cannot be stirred down. Immediately transfer hot jam to hot sterilized jars leaving ¼-inch headspace. Apply lids and bands. Process in a boiling water bath canner for 10 minutes. Turn off heat. Remove canner lid and let jars stand for 5 minutes, then remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
Makes about 3 cups.
Recipe inspired by Preserving the Season by Mary Tregellas; and Jane Robert via happybellyafter.com
Try this soft jam spooned over cake, ice cream or slather it on a biscuit — but be sure to have a napkin handy.
No-Cook Raspberry Freezer Jam
18 ounces raspberries
¾ cup granulated sugar
2 tablespoons PLUS 1 teaspoon freezer-jam pectin
Zest of 1 lemon
10 drops rosewater (extract), optional
Place the raspberries in a 9-by-13-inch baking dish (or other dish they'll fit into in a single layer) and mash with a potato masher until pulpy. (If a seedless jam is desired, press mixture through a medium sieve; reduce sugar to 10 tablespoons and pectin to 2 tablespoons).
In a medium bowl, combine the granulated sugar, pectin and lemon zest. Mix well. Add the berry mash and stir constantly for 3 minutes. Ladle mixture into freezer jars, leaving ½-inch headspace and let stand for 30 minutes. Refrigerate for up to 3 weeks or freeze for 1 year.
Makes about 4 (4-ounce jars) seedless jam or about 3 (half-pint) jars seeded jam.
Whole Berries in Light Syrup
5 cups water
1 ½ cups sugar
4 to 5 cups whole blackberries and raspberries, rinsed
Prepare your jars, lids and boiling water bath canner.
In a medium saucepan, combine sugar and 5 cups water. Cook, stirring occasionally, until mixture comes to a boil. Remove from heat.
Pack berries tightly into hot, sterilized jars. Pour in enough hot syrup to cover berries, but leave ½-inch headspace. Apply lids and bands. Process in a boiling water bath canner for 8 to 10 minutes. Turn off heat. Remove canner lid and let jars stand for 5 minutes, remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
Makes 5 (1/2-pint) jars.
Recipe adapted from "Complete Guide to Home Canning, Agriculture Information Bulletin No. 539, USDA"
No-Pectin Blackberry Jam
3 pounds blackberries
3 cups granulated sugar
2 tablespoons lemon juice
Have ready a thermometer or place a couple of saucers in the freezer.
In a large pot, combine berries, sugar and lemon juice. Let macerate at least 30 minutes.
While the berries macerate, prepare your jars, lids and water bath canner.
Bring berry mixture to a boil, stirring occasionally. When mixture reaches a full, rolling boil that cannot be stirred down, boil, stirring constantly, until mixture reaches 220 degrees on a thermometer or gels when tested on a saucer in the freezer.
To test using a saucer in the freezer, place about a teaspoon of jam on the frozen saucer and return it to the freezer for 1 minute. After a minute, push on the jam using your finger. It should wrinkle — like a silk or satin shirt or shar-pei dog. If the mixture does not wrinkle, the jam is not ready. Continue cooking and stirring. The mixture will thicken and look quite glossy. Another clue it is ready is if you can see the bottom of the pot for a brief second when you run a spoon through the mixture.
Once the mixture gels and/or reaches 220 degrees it is ready.
If a traditional seeded jam is desired, ladle the hot jam into the hot canning jars, top with lids and screw bands. Process in a boiling water bath canner for 10 minutes. Turn off heat. Remove canner lid and let jars stand for 5 minutes. Remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
If a smoother, less seedy jam is desired, pass mixture through a medium-sieve or conical strainer, but don't discard the pulp — it still has plenty of flavor to give. Give the strained jam a good stir and ladle into jars and proceed as above.
Makes 2 (½-pint) jars seedless jam or 5 (½-pint) jars seeded jam.
Recipe based on a recipe for Universal Jam in The New Homemade Kitchen by Joseph Shuldiner
The discarded seed pulp can be made into a delicious blackberry syrup ideal for mixed drinks, waffles, cakes and other desserts.
Blackberry Syrup
1 ½ to 2 cups seed pulp leftover from straining jam mixture
1 or 2 bags jasmine tea, optional
3 cups water
In a saucepan, combine the blackberry seed pulp, tea bags and water. Bring mixture to a boil, then strain. Ladle the liquid into a clean jar or bottle. If desired, the syrup can be processed to prolong its shelf life. Process in a boiling water bath canner for 10 minutes. Turn off heat. Remove canner lid and let jars stand for 5 minutes. Remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
Makes about 3 (½-pint) jars.
No Pectin Blueberry-Mint Jam
4 pounds blueberries
1 pound sugar
½ cup lemon juice
1 teaspoon coarsely ground black pepper
½ cup finely chopped mint
Pick over the blueberries, make sure to discard any stems or other debris. Rinse and thoroughly dry the berries.
In a large bowl, combine the blueberries, sugar and lemon juice. Cover and macerate mixture at room temperature for 12 to 48 hours (we let ours macerate for about 30 hours).
Have ready a thermometer or place a couple of saucers in the freezer.
Prepare your jars, lids and boiling water bath canner.
Scrape the blueberry mixture into a large pot (mixture should fill the pot by no more than a third). Cook over medium heat, stirring frequently, until berries release their juice. Stir in the black pepper. Continue cooking and stirring until mixture reaches a full, rolling boil. Boil until mixture reaches 220 degrees or reaches desired gelling consistency, 15 to 25 minutes.
To test using a saucer in the freezer, place about a teaspoon of jam on the frozen saucer and return it to the freezer for 1 minute. After a minute, push on the jam using your finger. It should wrinkle -- like a silk or satin shirt or shar-pei dog. If the mixture does not wrinkle, the jam is not ready. Continue cooking and stirring. The mixture will thicken and look quite glossy. Another clue it is ready is if you can see the bottom of the pot for a brief second when you run a spoon through the mixture.
Once the mixture gels and/or reaches 220 degrees it is ready.
Remove from heat and stir in the mint. Fill hot jars with hot jam, leaving ½ inch headspace. Use a skewer to remove any air bubbles. Wipe rims, apply lids and bands and process for 10 minutes in a boiling water bath canner. Turn off heat. Remove canner lid and let jars stand for 5 minutes. Remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
Makes 5 (½-pint) jars.
Recipe adapted from It Starts With Fruit by Jordan Champagne
Reduced-Sugar Strawberry Jam
1 ¾ cups unsweetened apple juice
3 tablespoons no/low sugar pectin
3 cups crushed strawberries
Up to 1 ½ cups granulated sugar
In a heavy saucepan, whisk together the juice and pectin and bring mixture to a full, rolling boil (one that cannot be stirred down). Stirring constantly, boil for 1 minute. Remove from heat and immediately add the fruit. Stir vigorously for 1 minute. Stir in the sugar and mix well.
Ladle jam into jars or containers, leaving ¼ to ½-inch headspace. Apply lids and let cool at room temperature for 30 minutes, then refrigerate jam until set, up to 24 hours. Jam is ready to serve or freeze after 24 hours. Will keep, refrigerated for up to 3 weeks or frozen for up 1 year. Alternately, process jars in a boiling water bath canner for 10 minutes. Turn off heat. Remove canner lid and let jars stand for 5 minutes. Remove jars to a towel-lined counter and let stand undisturbed for 12 to 24 hours. Check seals and store. Refrigerate any jars that did not seal.
Makes about 5 (½-pint) jars.
Variation: Strawberry Balsamic Jam: Stir 1 ½ tablespoons good quality balsamic vinegar and about a ¼ teaspoon cracked (not ground) black pepper (optional) in with the fruit.
Recipe adapted from Ball