Potatoes and Sweet Potatoes
Canning New White Potatoes
IMPORTANT: Safe canning recipes have only been developed for whole or sliced potatoes. Do not can mashed, pureed, or riced potatoes.
Recommended Varieties
Select the “waxy” or “boiling” kinds. Most red-skin potatoes are suitable, and many white or gold round new potatoes with thin skins work well, too. Avoid potatoes that are typically used for baking, such as russets—their mealy texture does not result in a good-quality canned product.
Quantity
An average of 20 pounds is needed per canner load of 7 quarts; an average of 13 pounds is needed per canner load of 9 pints.
Quality
Select small to medium-sized mature potatoes about 1 (2.5 cm) to 2 (5 cm) inches in diameter. Avoid tubers stored below 45°F (7°C), as they may discolor when canned. The idea is to select potatoes that are less mature, which tend to be less starchy than older potatoes.
Procedure
Read “Let’s Preserve: Basics of Home Canning” before starting. Start with clean countertops and utensils. Wash hands with soap and warm water. All produce should be properly washed before it is consumed or preserved. Gently scrub potatoes with a clean vegetable brush under cold running water. Do not soak produce in water. Peel potatoes. (Process times have not been determined for unpeeled potatoes.) If desired, cut into ½-inch (2.5 cm) cubes. Cover peeled or cut potatoes in a solution containing 1 teaspoon (3,000 milligrams) of ascorbic acid in 1 gallon of water to prevent darkening. Drain when ready to process. Place potatoes in pot of hot water, bring to a boil, and simmer whole potatoes for 10 minutes, cubes for 2 minutes. Drain and pack the hot potatoes in preheated jars to about 1 inch (2.5 cm) below the jar rim. If desired, add ½ teaspoon canning salt to pints, 1 teaspoon to quarts. Fill the packed jars with boiling water, leaving 1 inch (2.5 cm) of headspace. Remove air bubbles and wipe the jar rims. Adjust lids and process.
To Process in a Pressure Canner
Place jar rack, 2 (5 cm) to 3 inches (7.5 cm) of hot water, and sealed jars in the canner. Fasten lid and heat canner on the high setting. After exhausting steam for 10 minutes, add a weighted gauge or pressure regulator or close the petcock to pressurize the canner. Start timing the recommended process when the desired pressure is reached. Regulate heat to maintain a uniform pressure. When processing is complete, remove the canner from heat. Let the canner cool down naturally until it is fully depressurized. Then slowly remove the weighted gauge or open the petcock, wait 10 more minutes, and unfasten and carefully remove the canner lid.
Remove jars from the canner with a jar lifter, being careful not to tilt the jars, to a wooden cutting board or towel-lined surface. Do not retighten screw bands. Cool jars for 12 to 24 hours and remove screw bands. Check lid seals. If the center of the lid is indented, the jar is sealed. Wash, dry, label, and store sealed jars in a clean, cool, dark place. If the lid is unsealed, examine and replace jar if defective, use new lid, and reprocess as before or store in the refrigerator. Wash screw bands and store separately. Canned goods are best if consumed within a year and are safe as long as lids remain vacuum sealed. Process pints for 35 minutes and quarts for 40 minutes in a dial gauge pressure canner at 11 pounds of pressure or in a weighted gauge pressure canner at 10 pounds of pressure. Increase canner pressure at high altitudes as shown in Table 1 on the first page:
LET’S PRESERVE: Table 1. Pressure adjustments for elevation.
Dial Gauge Canner
0 to 2,000 feet, 11 psi; 2,001 to 4,000 feet, 12 psi; 4,001 to 6,000 feet, 13 psi; 6,001 to 8,000 feet, 14 psi
Weighted Gauge Canner
0 to 1,000 feet, 10 psi; 1,001 feet and above, 15 psi.
Freezing White Potatoes
New Potatoes (Whole)
Select smooth, new, small potatoes of the waxy type as described for canning. It is best to freeze them as soon as they are harvested from the garden. Peel or scrape and wash. Cover peeled potatoes in a solution containing 1 teaspoon (3,000 milligrams) of ascorbic acid in 1 gallon of water to prevent darkening. Drain. Water blanch for 3 to 5 minutes, depending on the size. The potato must be heated throughout to prevent enzymatic reactions, which can cause the centers to become discolored. After blanching, cool, drain, and package whole or sectioned pieces, leaving about ½ inch (13 mm) of headspace to allow for expansion. Seal and freeze. For cooking, add the frozen potatoes to enough boiling water to cover and cook for about 15 minutes or until tender.
French Fried Potatoes
For best quality, use mature, high-starch potatoes, such as Idaho or russet types, that have been stored for at least 30 days. Do not use freshly harvested potatoes. Wash, peel, and cut into ⅜-inch (9.5 mm) strips. Rinse quickly in cold water to remove the surface starch. Dry thoroughly using a paper towel. Fry small amounts in deep, hot fat (360°F, 182°C) for about 5 minutes until tender but not brown. Drain on a paper towel to cool. If desired, use a tray pack so that individual portions can be used; arrange fries in a single layer on a baking tray and freeze until solid. Package in zip-type bags or plastic freezer containers, seal, and freeze.
Another method of preparing the strips is to spread them in a single layer on a shallow pan and brush them with melted butter or oil. Bake in a preheated oven at 450°F (232°C) until golden brown and tender. Turn occasionally. Cool in the refrigerator and then pack, seal, and freeze.
At serving time, finish browning in a hot oven (475°F) (246°C). French fries are best if used within 2 months.
Prepared Cooked Potatoes
Prepared cooked potatoes tend to lose flavor rapidly when frozen, and should be used within 2 to 4 weeks. When a potato is frozen, the water in the potato separates from the starch, causing the reheated potato dish to be watery. When possible, add potatoes to frozen dishes when they are ready to be served.
Mashed Potatoes
Prepare mashed potatoes using your favorite recipe. Mash the potatoes or press them through a ricer so they are not chunky. Quickly cool and proceed with one of the following methods.
Method 1: Form into ½-inch-thick (13 mm) patties. Freeze patties on a cookie sheet before packing them into containers or freezer bags. Store with a double layer of freezer paper or plastic wrap between patties. To reheat for serving, they can be fried in butter until brown or brushed with melted fat and broiled.
Method 2: Spoon chilled mashed potatoes into a plastic freezer bag and press it flat to force the air from the bag. Place the filled bags on a tray and freeze until solid. Then stack the bags to save space in the freezer. The prepared potatoes may also be frozen in a straight-sided container. To serve, thaw just enough to slip potatoes into top of double boiler and heat over boiling water to 165°F (73°C) or higher. Another option is to microwave them in 30-second to 1½-minute increments, depending on amount, in a covered container, stirring them at the end of each time segment.
Method 3: Make individual servings by shaping the mashed potatoes into mounds or balls. Use an ice cream scoop to scoop serving-sized portions onto a baking sheet. Freeze solid and package. To serve, take out as many mounds as you need to heat or put on top of a casserole. They can also be reheated in the microwave. Frozen mashed potatoes are best used within 2 to 4 weeks.
Hash Browned Potatoes
Prepare hash browned potatoes as you would to serve, brown only to the brown-and-serve stage, cool, and package for freezing. For best quality, store frozen for no more than 1 to 2 months.
To serve, finish cooking and browning as for regular preparation.
Scalloped Potatoes
Prepare scalloped potatoes as usual and bake until they are almost tender and have a delicate brown color. Leave in the baking dish and allow them to cool at room temperature for no more than 2 hours. Cover with moisture-resistant paper and wrap in heavy duty foil or place them in plastic freezer bags. Freeze. Store frozen for no more than 2 to 4 weeks. To prepare, bake them frozen or partially thawed at 400°F (204°C) until heated through.
Stuffed Baked Potatoes
Remove the cooked potato from the skin, mash it, and return it to the skin. Allow the potatoes to cool at room temperature for no more than 2 hours. Wrap in foil and freeze. Store frozen for 2 to 4 weeks. T o serve, remove the wrap and bake in a 425°F (218°C) oven to an internal temperature of 165°F (73°C) (about 30 minutes).
Canning Sweet Potatoes
Quantity
An average of 17 pounds is needed per canner load of 7 quarts; an average of 11 pounds is needed per canner load of 9 pints.
Quality
Choose small to medium-sized sweet potatoes within 1 to 2 months after harvest. They should be mature, but not fibrous. Allow freshly dug sweet potatoes to cure at least 1 week after harvesting.
Procedure
Wash sweet potatoes and boil or steam until partially soft (15 to 20 minutes). Cool only enough to handle and remove skins. Cut medium potatoes if needed so that pieces are uniform in size, no larger than 2¼ inches (6 cm) in diameter. Fill sweet potatoes into hot jars, leaving a space of 1 inch (2.5 cm) below the rim. Add ½ teaspoon of canning salt to pints, 1 teaspoon to quarts, if desired. Fill the packed jars with boiling water or boiling syrup, leaving 1 inch (2.5 cm) of headspace. Options for syrup preparation are 2 cups of white or brown sugar to 5 cups of water or 1 cup of honey and 1 cup of white sugar to 5 cups of water. Before sealing, remove air bubbles and wipe the jar rims. Adjust lids and process in a pressure canner. Process pints for 65 minutes and quarts for 90 minutes in a dial gauge pressure canner at 11 pounds of pressure or in a weighted gauge pressure canner at 10 pounds of pressure. Increase canner pressure at high altitudes as shown in Table 1.
Freezing Sweet Potatoes
Procedure
Choose medium to large sweet potatoes that have been cured for at least one week. Sort according to size and wash. Cook until almost tender in water, steam, a pressure cooker, or the oven. Let stand at room temperature until cool. Peel sweet potatoes, cut in halves, slice, or mash. If desired, to prevent darkening, dip whole sweet potatoes or slices for 5 seconds in a solution of ½ cup of lemon juice to 1 quart of water. To keep mashed sweet potatoes from darkening, mix 2 tablespoons of orange or lemon juice with each quart of mashed sweet potatoes. Pack into containers, leaving ½ inch (13 mm) of headspace. If desired, use a tray pack for halves or slices so that individual portions can be used; arrange pieces in a single layer on a baking tray and freeze until solid. Package in zip-type bags or plastic freezer containers, seal, and freeze.
Baked Sweet Potatoes
Wash, trim, and heat potatoes in oven at 350°F (176°C) without peeling until slightly soft. Cool, remove peel, and wrap individually in aluminum foil. Place in plastic freezer bags and freeze. To serve, complete the baking in an oven at 350°F (176°C) immediately before serving, leaving the potatoes wrapped in foil.
Sweet Potato Balls
Make mashed sweet potatoes. Form into balls. Brush with melted butter or margarine. Roll in crushed cereal flakes or finely chopped nuts. Freeze balls on baking sheet before packaging in rigid containers or freezer bags. Fill air spaces with freezer paper. To serve, bake on greased baking sheet in a 350°F (176°C) oven for 25 to 30 minutes, until the internal temperature reaches 165°F (73°C). They should be steaming hot before serving.
Source
So Easy to Preserve. 6th ed. University of Georgia, 2014.
IMPORTANT: Safe canning recipes have only been developed for whole or sliced sweet potatoes. Do not can mashed or pureed sweet potatoes.
For additional information about food preservation, visit the Penn State Extension Home Food Preservation website at extension.psu.edu/food/preservation, or contact Penn State Extension in your county.
Prepared by Martha Zepp, extension project assistant; Andy Hirneisen, senior extension educator; and Luke LaBorde,, professor of food science.
