In this brief guide, we are going to answer the question “how to preserve leaves” and discuss the methods used to preserve leaves.
How to preserve leaves
Leaves can be preserved by:
Leaves are an excellent source of nutrition with few calories. Kale, cabbage, spinach, lettuce, collard greens and watercress are some common leafy greens.
Unfortunately, green leaves have a very short shelf-life at room temperature and are susceptible to drying, wilting and yellowing.
How to preserve leaves by refrigerating
Refrigerating is the best short-term preservation method for leafy greens.
Most leaves can be refrigerated for about 2 weeks. Refrigerating is the easiest way to preserve leaves, and the flavor and texture are retained throughout. It is recommended to store green leaves in the back of the refrigerator where the temperature is most stable.
To refrigerate green leaves:
- Rinse the leaves and pick out any yellow or damaged leaves.
- Dry the leaves with a paper towel or a salad spinner. Make sure that the leaves are completely dry as even a little moisture can cause spoilage.
- Wrap the leaves with a paper towel or line an airtight container with paper towels.
- Place the leaves in a sealable bag or inside the airtight container.
- Seal, label and refrigerate for up to 2 weeks.
Green leaves can also be placed upright in a glass of water and then refrigerated. This method is useful for hardier leaves such as kale and it will retain freshness for a longer time.
How to preserve leaves by freezing
Most leaves are frozen whole. Leaves can also be frozen as a puree. Freezing whole leaves will retain the quality as well as the nutrient content. Some freezing methods recommend blanching before freezing and some say it is best to freeze without blanching.
Leafy greens such as kale, collard greens and spinach can be frozen for up to 9 months without blanching.
If the leaves are blanched before freezing, they can be preserved for about 1 year. This is because blanching reduces enzyme activities in the leaves which cause decomposition. Through blanching, the color, texture and flavor can be preserved for a longer time.
Blanching also removes oxalic acid in green leaves. A high concentration of oxalic acid is usually associated with kidney stones. During blanching, oxalic acid is released into the water.
How to preserve leaves by drying
Drying is usually used to preserve herbs that are used for flavor and seasoning. Green leaves such as kale can also be dried and then powdered. The powdered leaves can be added to juices, smoothies and soups for an extra boost of nutrition.
Drying will preserve leaves for about a year. However, all the texture and some flavor and aroma will be lost by drying.
Dried leaves must be stored in an airtight container in a cool, dark place away from moisture. Dried leaves can also be frozen for about a year and a half but once again, there will be a loss of flavor.
Some herbs and leaves preserved by drying include parsley, basil, kale and spinach.
There are several methods to dry leaves, such as:
- Using a food dehydrator
- Using an oven
- Using a microwave
Using a food dehydrator is the easiest and most efficient method.
To dry leaves using a food dehydrator :
- Wash and dry leaves using paper towels or a salad spinner.
- Trim off the stems.
- Arrange the leaves on the dehydrator tray.
- Dry according to the temperature suggested in the dehydrator manual.
- Store the dried leaves in an airtight container. The leaves can also be ground to powder in a food processor at this stage.
How to preserve leaves by canning
Canning is not commonly used to preserve leaves. However, some leafy greens such as spinach, kale and chard preserve well by canning. If a pressure canner is used, leaves can be canned and stored for a long period.
A major drawback of canning includes changes in taste and technical difficulties. Canning green leaves require a pressure canner and it is also a time-consuming method.
To can leaves:
- Rinse leaves and discard any damaged and yellowed leaves.
- Blanch the leaves until they are just wilted.
- Pack the blacked leaves into hot jars. Salt can be added at this stage, but it is optional.
- Top off the jars with boiling water leaving about 1 inch of headspace.
- Wipe off the rims of the jars and place the lids on the jars.
- Process the jars using a pressure canner.
- Allow the jars to cool.
- Label and store the jars in a cool dark place.
More about canning leaves can be found here.
In this brief guide, we answered the question “how to preserve leaves” and discussed in depth the main methods used to preserve leaves.
If you have any questions or comments, please let us know.