By CARLA Y. BUSH
Strawberries are in season, but only for a short time. One way to enjoy local strawberries year round is to preserve them.
Strawberries can be frozen, made into jams and jellies or dried says Dr. Janie Burney, a professor and food preservation specialist with the University of Tennessee Extension Department of Family and Consumer Sciences. Burney is often asked to review the basics of food preservation and here are her responses to a set of questions specifically about preserving one of Tennessee's favorite local commodities: strawberries.
Question: I would like to make strawberry jam this year. What is pectin and do I need to use it in my strawberry jam?
Burney: Pectin is the substance that causes the fruit to gel. Some fruits have enough natural pectin to make a good jelly or jam, others required added pectin. The best pectin is found in just-ripe fruit. Fruit that is under-ripe or over-ripe will not form a gel. Although there are recipes for strawberry jam without added pectin, strawberries jam is easy to make with commercial pectin.
Commercial pectin can be used with any fruit. The advantages of commercial pectin are (1) fully ripe fruit can be used; (2) cooking time is shorter and is set, so there is no question when the product is done; and (3) the yield from a given amount of fruit is greater. However, there is sugar in regular commercial pectin and some people feel the extra sugar masks the flavor of the fruit.
Question: I would like to freeze my strawberries. What method do you recommend?
Burney: There are several ways that work well. Begin by washing and removing caps from strawberries. For whole strawberries in a syrup pack, put berries in a freezer container and cover with cold 50 percent syrup. To make 6 cups of syrup, dissolve 4 cups sugar in 4 cups lukewarm water, mixing until the solution is clear. Chill syrup before using. Leave at least ½ inch headspace so that berries have enough room to expand during freezing. You may need as much as 1½ inches of headspace for quart containers with a narrow top opening. Seal and freeze.
For whole berries in a sugar pack, add ¾ cup sugar to 1 quart (1 1/3 pounds) strawberries and mix gently until sugar dissolves or let stand 15 minutes. Pack the containers leaving at least ½ inch of headspace. Seal and freeze.
For sliced or crushed strawberries, slice or crush prepared fruit partially or completely. Add ¾ cup sugar to 1 quart of berries and mix thoroughly. Stir until most of the sugar is dissolved or let stand for 15 minutes. Pack into containers leaving at least ½ inch headspace. Seal and freeze.
Question: Do I need to use sugar when I freeze my strawberries?
Burney: No, you can freeze strawberries and other berries without sugar. However, unsweetened packs generally yield a product that does not have the plump texture and good color of those packed in sugar. The fruits freeze harder and take longer to thaw.
There are a couple of methods you can use for unsweetened packs of fruit. For a dry pack, pack the fruit into a container leaving enough headspace, seal and freeze. This is a good method for small whole fruits. If you want the fruit to be easier to remove from the container, spread a layer of prepared fruit on shallow trays and freeze. When frozen, promptly package and return to the freezer to prevent freezer burn.
If you do not want to use a dry pack, unsweetened fruit can be packed in water, unsweetened juice or pectin syrup. The pectin syrup is often used for fruits such as strawberries or peaches because it helps them retain their texture better than if frozen in water or juice. To make a pectin syrup mix 1 box powdered pectin in 1 cup of water. Heat until boiling and boil 1 minute. Remove from heat and add the remaining water. Let the syrup cool. This will make about 3 cups of moderately thick syrup.
Question: Is it okay to use artificial sweeteners when I freeze my strawberries?
Burney: Yes, both saccharin and aspartame work well in frozen products, or you can add them to the fruit just before serving. They provide a sweet flavor, but do not have the beneficial effects of sugar, such as color protection and thickness of syrup. Sucralose can be used when freezing food, but like any artificial sweetener, some people notice an aftertaste. It is suggested that you start by trying less than a full substitution for sugar to see what you like.
Question: Can I dry strawberries?
Burney: Yes, they can be dried. Sweeter varieties with a full red color and firm texture dry best. Gently wash the strawberries in plenty of cold water. They do not require pre-treatment but can be dipped into a solution of ½ teaspoon of ascorbic acid (vitamin C) per cup of water. Drain berries and remove the cap. Cut into ½ inch slices, or for smaller berries, cut them in half. Dry berries skin-down in a single layer. Depending on what method you use and their size, they can take about 24-36 hours to dry at about 1400F. A properly dried strawberry will be pliable and leathery with no pockets of moisture.
Question: What about homemade fruit rolls or leathers?
Burney: Strawberries make excellent fruit leathers Choose ripe or slightly overripe berries. Wash in cool water and purée until smooth. Sugar is optional. Use ¼ to ½ cup sugar, corn syrup or honey for 2 cups of fruit. Corn syrup and honey are better than granulated sugar for longer storage. Pour fruit on a single large plastic sheet or several smaller sizes. Dry at 1400F for 6 to 8 hours in a dehydrator, up to 18 hours in an oven, or 1 to 2 days in the sun. Test for doneness by touching center of leather; there should be no indention. While warm, peel from plastic and roll.
UT Extension provides a gateway to the University of Tennessee as the outreach unit of the Institute of Agriculture. With an office in every Tennessee county, UT Extension delivers educational programs and research-based information to citizens throughout the state. In cooperation with Tennessee State University, UT Extension works with farmers, families, youth and communities to improve lives by addressing problems and issues at the local, state and national levels.