Tom Yum Soup Recipe

Pre-cooking notes and tips

If you know your way around these ingredients and Thai cuisine, you can jump straight to the recipe card. For everyone else, I’ve gone a little deeper into the details below to help you feel confident making this iconic soup.

• Lemongrass, makrut lime leaves, galangal, and Thai red chilies are easy to find at Southeast Asian grocery stores. They’re available both fresh and frozen. Either works well. I’d avoid pastes or minced versions.
• I’ve also come across pre-portioned frozen bags that contain these four aromatics specifically for packaged tom yum soup. Convenient, yes, but I find that the quantity balance is often off. And when you add it all up, these aromatics end up costing quite a bit for the overall amount you get. I prefer buying everything separately.
• Lime leaves can also be found in the freezer aisle, but I prefer them fresh. Their flavor is brighter and more pronounced compared to frozen ones, although frozen works fine too. Don’t use dried leaves.
• When prepping lemongrass, trim off the dry, stiff top portion and the tough, bulb-like root end. Peel away the outer layer, cut the remaining stalk into 2-inch pieces, then use as needed.
• I get frozen stalks of lemongrass that already have the root end and the dry top portion trimmed off. Saves me a little bit of prep, and you can take out what you need and stash the rest back in the freezer.
• Galangal looks similar to ginger, but tastes very, very different and cannot be used interchangeably. I buy whole frozen galangal.
• When buying these aromatics frozen, look for vacuum-sealed packs if they’re available. Because I’m me, I also check a few and grab the one that looks the most tightly sealed. Vacuum sealing helps prevent freezer burn and does a better job of preserving the flavor.
• When I bring the four aromatics home, I portion them out into small tight packs using plastic wrap. Since I cook a variety of Thai and Asian dishes, like my arroz caldo that also uses lemongrass, I keep each one separate. Lemongrass packs in one bag, galangal packs in another, and so on.
• If you’re buying these ingredients just for tom yum, I’d portion them out into ready-to-use packs for one batch of soup.
• Nam Prik Pao is a classic Thai chili paste and one of the key ingredients in tom yum. It’s not something I’d skip. In Asian grocery stores, jars are usually labeled either “chili paste” or “chili paste with/in oil.” To make sure you’re getting the right kind, look for those made in Thailand. I get the Pantai brand (not sponsored).
• Fish sauce has a strong smell and flavor on its own, but don’t let that put you off. Used in the right amount, it adds a wonderful salty, umami flavor to the soup. A good quality fish sauce should have a short ingredient list, usually fish or anchovy extract, salt, sugar, and water. I use the Squid brand (again, not sponsored).
• Traditional tom yum is made with straw mushrooms, but I’ve used different kinds over the years, and most of them work fine. The one exception for me is shiitake. I find the flavor a little too noticeable, and it competes with other flavors in the soup.
• Personal favorite is white shimeji, aka beech mushrooms. They don’t need much prep, have a fairly neutral flavor, soak up the flavors of the soup, and have a pleasant bite.
• I’ve never used straw mushrooms because I’ve never been able to find fresh ones in stores here in Calgary. Also not a big fan of canned mushrooms, but if you want to use them, get whole peeled straw mushrooms.
• Different mushrooms need to be prepped differently. A quick search will tell you what to do depending on the type you’re using. For shimeji mushrooms, for example, I cut off the bottom cluster where all the stems are fused together. If that part has already been removed, I just trim off any brown, dried, or damaged ends. I usually leave them whole, but if you’re using a different, bigger mushroom, cut it into bite-sized pieces.
• Thai chilies work best for this soup. If you want to adjust the spice level, I’d change the amount of Thai chilies rather than swapping in another kind.
• This soup is also a great way to use up leftover rotisserie chicken. Throw it in at the same step where you’d add the shrimp. Since the chicken is already cooked, it only needs a quick warm-up.
• When I make this soup with raw chicken, I simmer bite-sized pieces of thighs in unsalted water until they’re fully cooked. Then I use that cooking liquid as the base for the soup instead of plain water while still adding the chicken powder. When I add fish sauce towards the end, I also stir in the cooked chicken.
• Your chicken powder may be different from mine. I use 8 cups of water in this recipe, but the chicken powder I use is measured for 6 cups of broth: 1 teaspoon per cup, which comes out to 2 tablespoons total. Check the instructions on the brand you’re using and use the amount recommended for 6 cups of broth.
• I don’t make or use shrimp broth. It’s a lot of work removing the shells, heads, and tails, simmering them, and putting in that extra time. For me, the combination of fish sauce and chili paste brings enough umami and seafood flavor to the soup. That gets an extra boost when the raw shrimp cook directly in the broth.
• I buy raw, peeled, deveined, tail-on frozen shrimp, but tail-off works too. No prep needed.
• Traditionally, lemongrass, galangal, and lime leaves are all left in the soup. Locals know not to eat them, but your guests might not, so give them a heads-up.
• Personally, I prefer taking them out. I use a spider strainer, or I pass the broth through a fine-mesh strainer.