Lemongrass keeps well with several preservation methods, from simple refrigeration (up to three weeks) to freezing (months of usable flavor). The best approach depends on how often you cook with it and how much you have on hand. Here’s how to handle each method so you get the most flavor out of every stalk.
Prep Your Stalks First
Before preserving lemongrass by any method, you need to break it down properly. The flavor is most concentrated in the bottom third of the stalk, the pale, fleshy section closest to the root. That’s the part most recipes call for. The woody green tops are too fibrous to chew, but they’re excellent in broths, soups, curries, and tea, so save them separately rather than tossing them.
Start by cutting off the bulb at the very base. It’s too woody to eat. Then peel away the tough outer layers until you reach the soft inner flesh. This step matters: people who find lemongrass unpleasantly chewy usually skipped this peel. Once you’ve exposed the tender core, you can slice it into thin rounds, mince it finely, or pulse it in a food processor depending on what you plan to cook later.
Refrigerating Fresh Lemongrass
Whole, uncut stalks last two to three weeks in the refrigerator when wrapped tightly in plastic and stored in the produce drawer. The plastic prevents moisture loss, which is what turns stalks dry and papery.
For even better results, try the water method. Trim your stalks to six to eight inches, remove any dry leaves, and stand them upright in a narrow jar with about one inch of cool filtered water, like cut flowers. Cover loosely with a produce bag (not sealed) and refrigerate. Change the water every 48 hours, rinsing the base of the stalks each time. This approach keeps lemongrass fresh for up to 21 days with excellent retention of citral, the compound responsible for that bright, lemony aroma. Only the bottom inch of the stalk should sit in water. Submerging more promotes rot.
Freezing for Long-Term Storage
Freezing is the most practical way to keep lemongrass on hand for months. You have a few options depending on how you typically use it.
Whole or Halved Stalks
Wash the stalks under cold water, pat them dry, and separate the green tops from the white lower portions. Place each group in a freezer bag, press out as much air as possible, and freeze flat. The outer layers you peeled off during prep can go in their own bag for stock. Whole frozen stalks work well when you plan to bruise them and simmer in soup or curry, then fish them out before serving.
Pre-Chopped in Ice Cube Trays
This is the most convenient method if you cook with lemongrass regularly. Roughly chop the tender white portions, then pulse them in a food processor until finely minced. Pack the chopped lemongrass into silicone ice cube trays with lids. Small trays with roughly two-teaspoon capacity per cube work well because you can pop out exactly what you need for a stir-fry or marinade without thawing the whole batch. Once frozen solid, transfer the cubes to a freezer bag for easier storage.
You can also skip the ice cube trays entirely and store a large batch of processed lemongrass in a single freezer bag. Flatten the bag before freezing so you can break off pieces as needed.
Drying and Dehydrating
Dried lemongrass loses some of its bright, citrusy punch but concentrates other qualities. It ends up higher in phenolic compounds and antioxidants than the fresh form, and it’s a good option for teas and spice blends where you want a subtler lemon flavor that stores indefinitely in a pantry jar.
If you have a food dehydrator, slice the stalks into thin rounds or short segments and dry at 50 to 65°C (roughly 120 to 150°F). At the lower temperature, expect about five hours of drying time. At the higher end, lemongrass dries in just over three hours. You’re done when the pieces snap cleanly and feel completely brittle with no bend or flexibility.
Without a dehydrator, you can air-dry lemongrass by spreading sliced pieces on a wire rack in a warm, dry room with good airflow. This takes longer, often several days, and works best in low-humidity environments. An oven set to its lowest temperature with the door cracked open is a faster alternative, though you’ll need to check frequently to avoid scorching. Store dried lemongrass in an airtight container away from light and heat.
Lemongrass Paste
Making a paste is a hybrid approach: you process the lemongrass now and freeze the result for instant use later. Pulse the trimmed, tender portions in a food processor with just enough neutral oil (or a splash of water) to help the blades catch. Scrape down the sides and process until you have a smooth or slightly textured paste. Spoon the paste into ice cube trays or spread it thin in a freezer bag so you can snap off portions. A tablespoon of paste replaces roughly one stalk in most recipes.
A Note on Oil Infusions
You might be tempted to preserve lemongrass in oil, but this comes with a real safety concern. When fresh herbs sit in oil at room temperature, the low-oxygen, low-acid, moist environment is ideal for producing botulism toxin. If you infuse lemongrass in oil without acidifying it first, the infusion must stay refrigerated and be used within two to three days. Left at room temperature for more than two hours, it should be discarded. Acidification methods tested by food safety researchers have only been validated for garlic, basil, oregano, and rosemary, so lemongrass oil infusions don’t have established safe protocols for shelf storage. Stick to refrigeration and use them quickly.
Which Method Preserves the Most Flavor
Freezing retains the closest flavor to fresh lemongrass because it locks in the volatile essential oils, especially citral, before they can evaporate. The water-in-jar refrigeration method also performs well for shorter timelines, maintaining over 90% of citral content through three weeks. Drying changes the flavor profile more noticeably, shifting it toward a milder, more tea-like character while concentrating minerals and fiber. For punchy lemongrass flavor in curries, stir-fries, and marinades, frozen is your best bet. For teas and gentle seasoning, dried works beautifully.
Whatever method you choose, label your bags or jars with the date. Frozen lemongrass stays usable for several months but gradually loses potency. Dried lemongrass, stored properly, holds its flavor for about a year.