How to preserve kaffir lime leaves

In this brief guide, we are going to answer the question “how to preserve kaffir lime leaves” and discuss the methods used to preserve kaffir lime leaves.

How to preserve kaffir lime leaves?

Kaffir lime leaves can be preserved by the following three methods

• Refrigerating
• Freezing
• Drying

How to preserve kaffir lime leaves by refrigerating

Refrigerating is the best short-term preservation method for kaffir lime leaves. However, prolonged storage might cause a chilling injury in the leaves and thus, accelerate the physiological and biochemical changes within the plants causing the loss of cellular integrity and leading to cell death. Studies show that kaffir lime leaves exposed to prolonged storage at 8°C may suffer chilling induced quality loss (1).

Kaffir lime leaves can be refrigerated for about 2 weeks. Refrigerating is the easiest way to preserve kaffir lime leaves, and the flavor and texture are retained throughout.

To refrigerate green kaffir lime leaves:

• Wash the kaffir lime leaves under running water.
• Drain the excess water using a colander.
• Blot dry the leaves using a paper towel or allow them to air-dry.

• Place the kaffir lime leaves in a ziplock bag and squeeze out all the air.
• Seal, label and place it in the crisper drawer of the refrigerator for up to 1 week.

A study showed that cold storage led to an increase in the amount of phenolic compounds present in the kaffir lime leaves after 18 days. This was explained by the action of the phenylalanine ammonia lyase (PAL) enzymes, which is the precursor for phenolic synthesis in the plants. Several studies have reported that PAL is highly active under chilling conditions and might have induced the phenolic production in the leaves. However, there was a reduction in the ascorbic acid concentration in the leaves (1).

How to preserve kaffir lime leaves by freezing

Kaffir lime leaves can be frozen for about 1 year.

Freezing kaffir lime leaves will significantly reduce their flavor and aroma. The longer they are frozen, the less flavourful they become.

However, studies showed that kaffir lime leaves should be stored either dried or fresh, thus its low temperature storage leads to chilling injury (1). One of the main consequences of chilling injury is the loss of volatile organic compounds, which represents the most significant trait to determine the postharvest quality of fresh herbs. Leaves exposed to temperatures below 12 °C show characteristic chilling injury visual symptoms, such as, brown discoloration of the interveinal areas of the leaf, stem browning and collapse, loss of glossy appearance, wilting of the leaves and loss of characteristic aroma would lead to leakage of ionic intracellular content (3).

If frozen leaves are used in the dish, make sure to add more leaves than instructed in the recipe to get the best flavor. 

Frozen kaffir leaves do not have to be defrosted. They can be added to the dish directly from the freezer.

Frozen kaffir leaves can be defrosted and then refrozen. But refreezing will remove more flavor and aroma from the leaves., so it is recommended to freeze them only once.

To freeze kaffir lime leaves:

• Wash the kaffir lime leaves under running water.
• Drain the excess water using a colander.
• Blot dry the leaves using a paper towel or allow them to air-dry.

• Place the kaffir lime leaves in a ziplock bag and squeeze out all the air.
• Seal, label and place it in the freezer for up to 1 year.

How to preserve kaffir lime leaves by drying

Drying is usually used to preserve herbs that are used for flavor and seasoning. Green kaffir lime leaves can be dried and then powdered. The powdered kaffir lime leaves can be added to dishes in the same way as fresh and frozen leaves. Citronellal is the major aromatic profile in kaffir lime leaves oils, and the highest value of essential oil depends on it. The drying method is proven to significantly influence the quality of the content and composition of aromatic plants (2).

Drying will preserve kaffir lime leaves for about a year. However, most of the flavor and aroma will be reduced. Studies showed that the essential oil of kaffir lime leaves significantly decreased after drying (2).

Dried kaffir lime leaves must be stored in an airtight container in a cool, dark place away from moisture. Dried kaffir lime leaves can also be frozen for about a year and a half but once again, there will be a loss of flavor.

The best method to dry kaffir lime leaves is by using air drying. Air drying is gentle and does not use heat so it retains most of the flavor and aroma from the kaffir lime leaves. Air drying of aromatic herbs can be an effective method of preservation that inhibits growth of microorganisms and delays some biochemical reactions in the final product (2).

Air-drying the kaffir lime leaves can take anywhere from 3 days to a week, depending on the temperature of the surrounding

To dry kaffir lime leaves by air-drying :

• Wash the kaffir lime leaves under running water.
• Drain the excess water using a colander.
• Blot dry the leaves using a paper towel.
• Tie the leaves together in a bunch using a twine.
• Hang the leaves upside down in a warm, dark and dry room with good ventilation. The leaves can also be spread out on a tray to air dry.
• Once the leaves are dry, transfer them into an airtight container. The leaves can also be powdered using a food processor.
• Label and store in a cool, dry place away from direct sunlight.

Alternatively, hot air drying is effective in preserving the kaffir lime leaves, when low drying temperatures are used (40- 60°C). Hot air significantly reduces drying time (4.9 hours at 60°C) (2).

Tips for preserving and using kaffir lime leaves

• Refrigerating and freezing: Kaffir lime leaves have a strong flavor and aroma. Their aroma could spread throughout your refrigerator or freezer and contaminate the other fruits and vegetables. To avoid this, always use thick, high-quality zip lock bags to store kaffir lime leaves.
• Washing: Make sure not to crush or damage the leaves while washing and drying them. Damaged leaves will lose their flavor and aroma.
• Using in a recipe: Always use a moderate amount of kaffir lime leaves. One or two leaves should be enough. You can find a recipe using kaffir lime leaves here.

How to use kaffir lime leaves in cooking

Kaffir lime is a citrus fruit. Both the fruits and leaves of kaffir limes are used in Southeast Asian cuisine, especially in Thailand, Indonesian and Malaysian cooking. Essential oil made from kaffir lime is used in perfumes (2).

Usually, both fresh and dried kaffir lime fruits and leaves are rich with strong, pungent and lime lemon aroma 3 and contain 0.08% essential oil. The leaf contains essential oil (about 80%) such as citronellol, citral, nerol and limonene. These essential oils are able to act as antioxidants and function as anticancer (2). 

Kaffir lime leaves emit a strong citrus flavor when they are crushed. They must be used in moderation to not overpower the other flavor of the dish. It is also served as a natural medicine to be used in various diseases including heart disease, dizziness, and indigestion and it also applied topically to keep the skin nourishment (1).

Kaffir lime leaves are added to salads, soups and curries. When adding kaffir lime leaves to salads, remove the center vein of the leaves and finely chop or shred the leaves. The whole leaves can be added to soups and curries, but make sure to remove the leaves before serving.

Conclusion

In this brief guide, we answered the question “how to preserve kaffir lime leaves” and discussed in depth the main methods used to preserve kaffir lime leaves. 

If you have any questions or comments, please let us know.

References

1. Venkatachalam, Karthikeyan. Changes in Phytochemicals and Antioxidant Properties of Kaffir Lime Leaves under Chilling Storage. Kaen Kaset= Khon Kaen Agri J, 2019, 47, 531-536.
2. Juhari, Nurul Hanisah, et al. Effect of hot-air drying on the physicochemical properties of kaffir lime leaves (Citrus hystrix). J Food Agri Environ, 2013, 11, 203-211.
3. Cozzolino, Rosaria, et al. Assessment of volatile profile as potential marker of chilling injury of basil leaves during postharvest storage. Food chem, 2016, 213, 361-368.