Before refrigeration, cooks fought a constant battle against spoilage, working hard to put up enough food to feed their families until the next harvest. Now putting up food is as easy as wrapping and freezing it. In this chapter, we concentrate on the most popular modern methods of food preservation: canning and freezing. And we offer a number of small-batch recipes that use less produce to take into account the needs of urban cooks and smaller families who want to enjoy healthful homemade canned goods. Also included are recipes for freezer jams, which are not processed in boiling water baths, but instead, simply stored in the freezer.
KEEPING THE COLOR BRIGHT
Some fruit will turn brown if left untreated after it’s been cut or peeled. Whether you’re canning or freezing, you may want to treat such fruit (like peaches and bananas) to keep their color bright. One way is to treat the cut fruit with an ascorbic acid solution prepared from a commercial mix, which is available in most supermarkets during canning season, as well as in drugstores. Ascorbic acid can also be added to the sugar syrup or mixed with a little water and sprinkled over the fruit. Or, in a large bowl, combine 4 quarts water, 2 tablespoons salt, and 2 tablespoons cider or white vinegar. Drop the peeled or cut fruit into the solution as soon as the fruit is prepared; let stand a few minutes, then remove and rinse well. Drain on paper towels.
CANNING
Today, most people process fruits and vegetables because they enjoy it, not because they have to. (Processing means heating food in canning jars at high temperatures for periods long enough to kill spoilage-causing microorganisms and enzymes that would alter the food’s flavor, texture, and color.) The fruits and vegetables for homemade pickles, jams, preserves, and jellies can come from an urban farmers’ market or the garden out back. Making homemade canned goods is a satisfying pleasure, and nothing produced commercially can equal the quality or flavor.
EQUIPMENT FOR CANNING FRUITS AND TOMATOES
Boiling water bath canning pot: If you plan on doing a lot of canning, you may want to purchase a canning pot. It comes with a basket to hold the jars and a tight-fitting lid. However, any large stockpot will do, as long as it is deep enough that the pot’s rim is 3 to 4 inches above the tops of the jars (as they sit on the wire basket or rack) and large enough that the jars don’t touch each other. Instead of a wire canning basket, you can use any sturdy heatproof rack that will fit in the pot; round wire cooling racks work well. If your improvised rack needs a little extra support to hold heavy jars, place several metal jar bands underneath the center of the rack.
Jars : Tempered glass canning jars, sometimes called Mason jars, are the only recommended jars for home canning. Their special two-piece lids ensure a vacuum-tight seal that discourages spoilage. Also, the specially treated glass will keep them from cracking when they’re subjected to extreme temperatures. If you plan to put your jars in the freezer, buy the ones with straight or tapered sides; jars with “shoulders” don’t work in the freezer.
Jars range in size from four ounces to half a gallon. Use the size recommended in the recipe, especially for hot water bath canning; if you use larger jars than recommended, the heat that kills harmful microorganisms may not penetrate all the way through the food or preserves may not set up properly. Wide-mouthed jars are easier to fill than narrow ones. The jars are reusable, but check them carefully beforehand for any signs of wear, like cracks or chips.
Caps : The most common cap is made of two pieces: a flat lid with a rubberlike sealing compound on the underside and a metal screw band that holds the lid in place during processing. You must use new lids each time you can food. Undamaged screw bands, however, can be reused.
Utensils for canning : A wide-mouthed funnel for transferring the food to the jars and a jar lifter to grip the jars so they can be easily lifted in and out of the boiling water aren’t essential but facilitate the canning process. To remove air bubbles, use a narrow rubber spatula (a metal spatula or knife could chip the glass).
CANNING STEPS
For best results, read these steps all the way through before you begin.
1. Prepare jars and lids for processing. Check the jars to be sure there are no chips or cracks. Wash the jars, lids, and screw bands in hot soapy water; rinse. The jars must be heated before canning to prevent breakage. Submerge them in enough cool water to cover; heat to boiling. Remove the pot from the heat and cover it. Leave the jars in the hot water for at least 10 minutes. Place the lids and bands in a saucepan with enough water to cover; bring to a simmer (180°F). Remove the pan from the heat, cover it, and keep hot until ready to use. Remove the jars and lids, one at a time, as needed.
2. Prep fruit/ tomatoes and pack jars. Fruit and tomatoes can be packed into the hot jars raw (cold pack) or slightly cooked (hot pack). In both methods, the fruit is covered with boiling hot liquid—water, juice, or sugar syrup. See the chart on pages for the best methods for the fruit you intend to can.
SUGAR SYRUP AND OTHER LIQUIDS FOR CANNING AND FREEZING
Fruit can be canned or frozen in syrup, fruit juice, or water. Sugar adds flavor and helps retain the color, but it is not needed to prevent spoilage. The sweetness of your fruit will determine whether you want a light or heavy syrup, but we give you recommendations in our charts.
If you want to make your own fruit juice for preserving, prepare it just before packing the fruit or making the sugar syrup. Place ripe, juicy fruit in a large nonreactive saucepan. With a potato masher or large spoon, crush the fruit well. Over low heat, stirring frequently, heat to simmering. Strain the juice through a double layer of cheesecloth; discard the fruit pulp.
To make sugar syrup, in a medium nonreactive saucepan, heat water or fruit juice and sugar over high heat, stirring until the sugar has dissolved. If directed, stir in ascorbic acid. Reduce the heat to low; keep it hot (do not boil) for canning; cool, then chill it for freezing.
LIGHT SUGAR SYRUP
4 cups water or juice and 11/3 cups sugar.
Yields 41/2 cups.
MEDIUM SUGAR SYRUP
4 cups water or juice and 2 cups sugar.
Yields 5 cups.
HEAVY SUGAR SYRUP
4 cups water or juice and 4 cups sugar.
Yields 6 cups.
Cold pack : Prep the fruit as indicated in the chart. Firmly pack the unheated raw fruit into hot jars, then fill with boiling liquid to within ½ inch of the rim. You will need ½ to 1½ cups of liquid for every 4 cups of fruit.
Hot pack : Heat the fruit to boiling in the liquid of your choice, or simmer it in its own juices. Cooking makes food more pliable and easier to pack, so you will need fewer jars. Pack the hot food loosely into hot jars and fill with boiling liquid to within 1/2 inch of the rim.
For both cold and hot pack : Headspace is important: If a jar has too little, the food may swell and force itself under the lid, breaking the seal. Too much headspace and the food at the top of the jar could discolor.
After filling each jar, with cold or hot food, run a narrow rubber spatula between food and side of jar to remove any air bubbles.
Using a clean, damp cloth, thoroughly wipe the jar rims and threads to remove any drips of food or liquid. Cover with the hot lids. Screw on the bands just until tightened; do not force.
3. Process jars. The filled jars must be processed in a boiling water bath immediately after packing to maintain the proper temperature. The processing time will vary according to the type of fruit, the method of packing, and the size of the jars.
Place the basket or a rack in the canning pot. Fill the pot halfway with hot water; heat it to simmering over high heat. In another pot or kettle, heat additional water to boiling. Carefully place the filled jars in the basket far enough apart so the water can circulate freely around them. The water level should be 1 to 2 inches above the tops of the jars; add boiling water if needed.
Cover the canner and heat the water to boiling. Start timing as soon as the water comes to a full boil; check often. Reduce the heat to maintain a gentle boil for the time indicated in the recipe. If necessary, add boiling water to keep the jars properly covered.
Once you’ve processed the jars the required time, turn off the heat, remove the lid, and let the jars sit in the hot water for 5 minutes.
4. Cool jars. In a draft-free place, line the counter surface with folded kitchen towels (contact with a cold, hard surface could break the jars). With a jar lifter, remove the jars from the pot and place them on the towels, allowing 1 to 2 inches between them for air circulation. (If any liquid has boiled out of the jars, do not open them to add more.) Cool to room temperature, at least 12 hours or up to 24 hours.
5. Test jars for airtight seal. When the jars are cool, check the seals. The lid should be slightly concave (indented), not flat or bulging. Also, if you hit the top of the lid of a properly sealed jar with a teaspoon, you will be rewarded with a high-pitched ringing sound. If you get a dull thud, you don’t have a proper seal. Any food in a jar that hasn’t sealed properly needs to be refrigerated and eaten within several days or reheated and processed in a newly sterilized jar with a new lid.
6. Store jars properly. Wipe the jars with a clean damp cloth to remove any food residue and label them, including the date of processing. Store the jars in a cool, dark place, preferably between 50° and 70°F. Under ideal conditions, home-processed foods will keep for about a year; after that, changes in the flavor, color, and texture will affect the quality.
SAFETY IN THE PANTRY
Before eating canned food, check the jar carefully for signs of spoilage. Do not taste or use any canned food if the lid is loose; there are gas bubbles; there is spurting liquid; the contents are moldy, slimy, or uncharacteristically soft or mushy; the color is unnatural; there is sediment at the bottom of the jar; or the food smells unpleasant.
If you reject the contents of a jar, destroy the food in such a way that it cannot be accidentally eaten by children or pets. Be sure to wear heavy plastic gloves when you handle it, as botulinum toxins can be fatal when ingested or absorbed through the skin. Afterward, thoroughly wash any surface that may have come in contact with the spoiled food using a chlorine solution, and discard any kitchen sponges used during cleanup.
MAKING JAM, JELLY, AND OTHER FRUIT SPREADS
If you have a large quantity of fruit and the inclination to do so, make a big batch of jam. And remember, you don’t always have to pull out the canning pot for water bath processing. Excellent jams can be prepared for storage right in your freezer (see for recipes).
The equipment you’ll need, if you’re canning, will be the same as for canning fruit, with the addition of a broad 8-quart Dutch oven for preparing large-batch recipes and a 12-inch skillet for small-batch skillet jams. Don’t use unlined aluminum pots or skillets, as they can react with the acid in fruit and affect the flavor and color.
When preparing the fruit, don’t puree it or it won’t set. Cook as directed.
Some recipes use commercial pectin to set mixtures properly. Pectin is a naturally occurring substance found in varying amounts in fruits; underripe fruit contains more pectin than fully ripe fruit. Commercial pectin comes in powdered and liquid forms: They are not interchangeable.
If the recipe calls for the fruit to come to a “rolling boil,” heat it until the mixture forms bubbles all across its surface that cannot be stirred down.
Skim off the foam. To do this, remove the pan from the heat. Use a large metal spoon to skim the foam from the surface.
Once you’ve cooked the jam, jelly, or fruit spread as directed, spoon it into hot jars prepared as instructed. For freezer jams, pack the jam into containers to 1/2 inch from the tops; cover tightly. Freeze. For processed spreads, preferably using a wide-mouthed funnel, fill and close the jars one at a time. For jellies, fill the jars to 1/8 inch from the tops; for jams, 1/4 inch from the tops. Wipe the rims of the jars with a clean, damp cloth. Place the lids on top, then screw on the bands.
Process, cool, test, and store the jars as instructed.
FREEZING
Freezing is a great way to preserve fruits and vegetables. (For information on freezing meats, poultry, and seafood, see the Storing sections of their respective chapters.) Freezing maintains the natural color and flavor of food better than other methods of preservation. For the best flavor and texture, all home-frozen fruits and vegetables should be used within nine months.
STORE IT RIGHT
Frozen food must be stored properly to prevent “freezer burn” (a tough, dry surface that forms when food is exposed to the air in the freezer). It is best to use storage materials designed specifically for the freezer. For long-term freezer storage (more than a month), use tempered glass jars suitable for canning and freezing, plastic freezer-safe containers, waxed cardboard cartons, foil containers, or heavy-duty ziptight plastic bags. Use waterproof markers for writing on labels or freezer tape.
FREEZING SUCCESS
Chill foods and liquids before packing.
Wipe edges of containers or jar rims clean.
When wrapping food in freezer wrap or using plastic bags, press out as much air as possible before sealing.
Label each package with the name of the food and the date packed.
Put only as much unfrozen food into your freezer as will freeze within twenty-four hours. (The rule of thumb is 2 to 3 pounds of food for each cubic foot of freezer space.) Overloading slows the freezing process and raises the temperature of the freezer, which affects the quality of the food already inside. Check the manufacturer’s instructions to see how much unfrozen food you can place in the freezer at one time.
Place the unfrozen packages against the freezing plates or coils, leaving enough space between them for the air to circulate. Freeze foods at 0°F or lower. After the packages are frozen, you can store them close together.
FREEZING FRUIT
There are three ways to freeze fruit: in syrup, in sugar, and dry pack (with nothing added). While some fruits can be frozen without sweetening, most have better flavor and texture if packed with sugar or in syrup. The chart Freezing Fruit lists the fruits that freeze well and the best methods for preparing them.
Packing Fruit for Freezing
To pack fruit in syrup, first prepare and completely chill the sugar syrup you intend to use. Each pint container usually takes 1/2 to 2/3 cup syrup. If directed to do so, add ascorbic acid to the cold syrup just before using it, taking care not to beat in any air bubbles. Pour about 1/2 cup of the syrup into the container, fill the container with fruit, and add enough syrup to cover the fruit, leaving the proper amount of headspace (see below). Press the fruit down under the syrup and hold it in place with a small piece of crumpled foil; remove foil. Close and seal the container.
HEADSPACE WHEN FREEZING PRODUCE IN LIQUID OR SUGAR
How much headspace you need to leave will depend on the size of the jar and the size of the opening:
Pint jar with wide top : 1/2 inch
Pint jar with narrow top : 3/4 inch
Quart jar with wide top : 1 inch
Quart jar with narrow top : 11/2 inch
To pack fruit in sugar, cut the fruit into a bowl and, if directed to do so, dissolve ascorbic acid in a small amount of water and sprinkle it over the fruit. Then sprinkle with the amount of sugar specified. With a rubber spatula, gently mix the fruit and sugar until the fruit releases its juices and the sugar has dissolved. Transfer the mixture to containers or jars, then close and seal, leaving headspace as directed above.
To dry-pack fruit, place the prepared fruit in a container or jar. If necessary, sprinkle dissolved ascorbic acid over the fruit and mix well just before packing. Close and seal, leaving a 1/2-inch headspace.
Tray-freezing before dry-packing is a great way to freeze fruit for use in baking or smoothies. It also prevents the fruit from sticking together. To do it, spread the fruit in a single layer, without touching, in a jelly-roll pan. Freeze until hard, 1 to 2 hours. Pack into heavy-duty zip-tight plastic bags, pressing out all the air.
To Thaw and Use Frozen Fruit
Thaw fruit in its sealed container in the refrigerator or in a pan of cold water on the counter.
To serve the fruit uncooked, serve it as soon as it has thawed (while a few ice crystals remain).
To serve the fruit cooked, thaw it just until the pieces can be separated. Add sugar to taste, keeping in mind whether or not the fruit was already sweetened; if needed, add 1 to 2 tablespoons water.
FREEZING VEGETABLES
Vegetables you intend to freeze should be fresh and at their peak of ripeness. Wash and drain them thoroughly. Sort them according to size, unless you plan to cut them up. Prepare each vegetable as directed in the Freezing Vegetables chart.
Step 1 : Blanching
Blanching vegetables before freezing is an essential step for some produce. Carefully follow the blanching time for each vegetable, because underblanching stimulates enzyme activity and is worse than no blanching at all.
Fill an 8-quart saucepot halfway with water and bring it to a full boil over high heat. Do not add salt unless this is specified in the chart. Place a small amount of vegetables (about 4 cups) in a wire basket or strainer so they can be lowered into and removed from the water at the same time. Completely immerse the basket in the boiling water; cover the pot and start timing immediately, without waiting for the water to boil.
Meanwhile, fill a large bowl halfway with cold water; add one tray of ice cubes. As soon as the blanching time is up, lift out the vegetables and plunge them into the iced water to stop the cooking and to cool them quickly. Stir several times; the cooling time should not exceed the blanching time. Drain thoroughly. The blanching water may be reused (return it to a full boil) ; the cooling water must be replenished with ice cubes for each batch of vegetables.
Step 2 : Packing
Pack vegetables without liquid into freezer-safe containers with the headspace specified in the chart, or into heavy-duty zip-tight plastic bags, pressing out all the air. Seal, label, and freeze.
Cooking Frozen Vegetables
Since blanching partially cooks the vegetables, the cooking time will be shorter than for fresh vegetables. Most can be cooked without being thawed first, although leafy vegetables, such as spinach, cook more evenly if thawed just enough to separate the leaves. Corn on the cob should also be partially thawed so the cobs can heat through in the same time it takes to cook the kernels.
Try to cook frozen vegetables in as little water as possible, as some nutrients are water soluble. Usually 1/2 cup water is enough to cook a pint of vegetables. For corn on the cob, use 2 to 3 inches of water. Salt the water lightly, if desired.
In a 2-quart saucepan over high heat, heat the water to boiling. Add the frozen vegetables and heat again to boiling, separating the pieces with a fork. Reduce the heat to medium and cover. Simmer just until the vegetables are tender. Drain, season as desired, and serve.