by Marnie Record, workforce specialist, Local Foods program, Lincoln Land Community College
The methods for preserving summer’s garden bounty reads similar to the famous line in Forrest Gump where Bubba recalls the long list of shrimp preparations and dishes. In food preservation there’s canning, freezing, drying, fermenting, pickling, curing, smoking, cellaring, salting and sugaring. Once a necessity for survival, preservation techniques are experiencing a renaissance with the growing interest for eating local farm fare. In cold Illinois winters, preservation offers a tasty way to dine on homegrown produce all year.
Here we take a closer look at two of the more common modern preservation methods. For speed and convenience, freezing tops the list. Freezing also provides the best way to capture peak flavors and nutrition. Five key factors to manage in the freezing process include enzymes, air, microorganisms, ice crystals and evaporation of moisture. Tips for optimal success in freezing vegetables:
- Blanch vegetable according to individual requirement to slow or stop the action of enzymes in the ripening process and brighten the color.
- Exclude air to prevent enzyme reactions and oxidation which cause surface browning.
- Maintain a temperature of zero degrees and use immediately after thawing. Unlike canning, freezing does not kill microorganisms in food.
- Bring food to freezing quickly to prevent large ice crystals that can rupture food cells and cause a soft, mushy texture.
- Use proper packing materials that protect moisture levels in the food. Long-term exposure to air causes plant fibers to dry, a process known as freezer burn.
Some foods, such as blueberries, can be frozen as they are without blanching, and a few items like lettuce and cream sauces do not freeze well. Freeze soup bases for a quick meal any time.
The oldest method of food preservation is drying. The drying process concentrates flavors, reduces the opportunity for moisture-loving bacteria to form, and requires the least storage space of the preservation methods. By drying food, you’re removing moisture without reaching cooking temperatures. Success stems from a balance of temperature and humidity. Food dehydrators make easy work of drying food, but it’s easy to do in an oven set on low heat, too. Or, dry food under a hot, dry sun like our ancient ancestors. If drying in the oven, open the oven door two to three inches to allow moisture to escape. A convection oven works well because it combines low heat with a fan to move the air.
Some peels toughen as they dry. In addition, skin reduces surface area, preventing moisture from escaping. Best practices suggest slicing for quicker drying and pieces of the same size, shape and thickness for a more even drying. Some thinly sliced fruits and vegetables will dry crisp, such as apple chips or zucchini chips. Place pieces on drying racks without allowing them to touch or overlap, and then into the dehydrator or oven. If the food is dried at a temperature that is too high, the outer surface will harden, preventing moisture from escaping from the center of the slice.
Looking for some inspiration to start preserving at home? Driftwood Cocktail and Eatery in downtown Springfield features a pickled or preserved food in just about every dish on their menu, but for the grand feast of preserved tastes try the Pickled Plate which comes on a reclaimed wooden barrel plank and features an expanse of flavor filled fruits, vegetables, jams and cheeses. The seasonal rotation ensures an ever-changing mix of deliciousness including a recent surprising favorite of pickled strawberries.
Blanching Vegetables for Freezing Process
1 pound vegetable of choice
Bring one gallon of water to an active boil. Lower one pound of vegetables into the water. Cover. Return to a boil.
Start counting the blanching time when the water returns to a boil. Blanching time varies per vegetable.
As soon as blanching is complete, vegetables should be cooled quickly in 3 to 4 gallons of cold water.
Chill at least as long as vegetables were blanched.
1 large bunch fresh kale
2 tablespoons olive oil
2 tablespoons vinegar
1 to 2 teaspoons kosher salt
Few twists freshly ground black pepper
One dash each cayenne and garlic powder (optional)
Preheat oven to 325 degrees.
Trim thick stems out of kale and set them aside to cook or compost. Chop remaining strips into bite-size pieces.
In a mixing bowl, stir together oil, vinegar and seasonings. Toss kale in mixture and marinate for at least 30 minutes.
Spread out kale in a single layer on a baking sheet and bake for about 15 minutes or until edges begin to brown. Let cool and store in an airtight container.
Blueberry Raspberry Fruit Leather
3 cups blueberries
1 cup raspberries
1 teaspoon lemon juice
1/2 cup sugar
Preheat the oven to 200 degrees F. Combine the fruit and sugar in a blender. Add the lemon juice and puree until smooth.
Transfer the pureed fruit to a medium saucepan and bring to a simmer over medium-high heat. Reduce the heat to medium low and cook, stirring occasionally at first and then more often toward the end, until most of the liquid evaporates and the mixture is very thick, 35 to 45 minutes.
Line a 12-by-17-inch rimmed baking sheet with a silicone mat or nonstick foil. Use an offset spatula to spread the fruit on the mat or foil into a thin layer. Bake until barely tacky, 3 hours to 3 hours, 30 minutes.
Transfer the baking sheet to a rack and let the fruit leather cool completely. Peel off of the mat or foil. If the leather is still moist on the underside, return it to the oven, moist-side up, until dry, about 20 more minutes. Lay the leather smooth-side down on a sheet of wax paper and use kitchen shears to cut it into strips on the paper. Roll up the strips and store in zip-top bags for up to 1 week.
For more information about food preservation, the Value-Added Local Food program at LLCC offers an eight week credit course covering a wide variety of food preservation methods from Sept. 14-Oct. 31 on Monday evenings from 5-9 p.m. For more information, call 217-786-4993. Also, the Culinary Institute at LLCC offers a non-credit class on the basics of canning and freezing on Aug. 8 from 8:30 a.m.-1 p.m. For more information, contact 217-786-2432.
Lincoln Land Community College offers credit programs in Culinary Arts, Hospitality Management, Baking/Pastry, and Value-Added Local Food, and non-credit cooking and food classes through our Community Learning Culinary Institute.
Cooking or food questions? Email email@example.com.