A Guide to Thai Curry Pastes

When I was growing up in Thailand, making curry paste was a commonplace kitchen task. The sound of aromatics being steadily pounded into a prik gaeng, or curry paste, in a granite mortar and pestle was one I heard daily, either emanating from our own kitchen or our neighbors’, even though it was just as common for all of us to make curries from pre-made curry paste purchased at the store. While buying curry paste may seem a little less romantic, it has the advantage of being far more practical, particularly when you use curry pastes in cooking as much as Thais do.

Thai curry pastes seem to be a bit of a mystery to foreigners. Their flavors are complex, and it can be difficult to determine what the ingredients in a paste are just by tasting it; there are also quite a lot of them, with varieties that are specific to different regions in the country, and even to different households. But they really aren’t all that complicated, and understanding how they’re made, what common types are made from, and how they’re used will help you both make traditional curries and encourage you to start improvising on your own.

Thai Curry Paste: A Definition

At its most basic level, prik gaeng is just a mixture of pulverized aromatics, herbs, and spices. That’s it. And while prik gaeng are used to make gaeng, or curries, they do not have to be used for curries; Thais treat them simply as a “flavor paste,” which can be used in anything you want. (More on that below.)

Just as you don’t have to use prik gaeng for curries, there really aren’t any rules governing which ingredients are or aren’t included in a paste, although I suppose there is one requirement: a prik gaeng has to contain prik, or chiles. Garlic, shallots, and shrimp paste are almost always added to prik gaeng, but aside from that, all non-leafy herbs and spices are fair game. A prik gaeng can be as simple as seven-ingredient paste, like a sour curry paste, or as extravagant as a 15-ingredient one, like massaman curry paste.

Thai Curry Paste Ingredients

Ingredients in curry pastes fall into the following categories:

Chiles: These can be dried or fresh, green or red (or any number of colors), spicy or mild, and the types of chiles used will determine the flavor and color of the final paste. Prik cheefa haeng, or dried red spur chiles, are the most commonly used type of chiles in curry pastes and they produce pastes with an intense red color. Most of the popular curries in North America—red curry, yellow curry, panang curry, and massaman—are made with pastes made with dried red chiles. The one obvious exception is green curry paste, which is made with fresh green chiles.

Fresh aromatics: In a rough order of the frequency with which these make it into curry pastes, these include shallots, garlic, lemongrass, galangal, cilantro root, makrut lime zest, grachai, turmeric, and ginger. Note that delicate, leafy herbs like cilantro or mint aren’t pounded into curry pastes because their flavors can’t withstand the amount of cooking that curry pastes are subjected to.

Dried spices: Dried spices are used relatively less frequently than other curry pastes ingredients, and their use is limited mostly to those pastes that have some Indian or Muslim influence. Coriander seeds and cumin make an appearance more often than other dried spices, but you sometimes see cinnamon, cardamom, nutmeg, mace, and cloves included in pastes, among others.

Umami boosters: Gapi, or fermented shrimp paste, is almost always added to curry pastes because it provides oomph, umami, and a little saltiness. It’s often added in small amounts so you can’t taste it, but in some curries, gapi’s funk is one of the main flavors. In addition to shrimp paste, you can also use dried shrimp to add savory depth and, in Northern Thailand, they sometimes use a fermented soybean product called tua nao, which can be difficult to find although it can sometimes be purchased online. For vegetarians, you can omit the shrimp paste if it’s just a small amount, or you can use miso paste as a substitute; miso will provide umami, but has an entirely different flavor. If you can find tua nao, that can also be used as a substitute.

Others: Occasionally you’ll see an ingredient that doesn’t fall into any of the above categories, like the roasted peanuts added to panang curry paste to add richness and thickness to the sauce. Peanuts are often omitted in pre-made pastes because of allergies, and so you’ll also sometimes see mung beans have been added instead. 

Kinds of Curry Pastes

It’s important to note that while there are some common types of curry pastes, there isn't an exhaustive list. There are hundreds of types of curries in Thailand, some are classics, and others are obscure or unique to specific regions. Also, people just make up their own curry pastes, according to what they feel like eating and what they have on hand: You can make a “prik gaeng” using whatever you want, use it to make a “curry” and put in it whatever you want, and the curry doesn’t need to have a name.

That being said, there are a few curry pastes that are so widely used that it’s worthwhile knowing what they are and what goes into them, and they can be divided into two main categories: curry pastes used to make coconut-based curries and curry pastes used to make water-based curries.

Coconut-Based Curry Pastes

Red - I consider red curry paste to be the “basic” curry paste. It’s incorporated into far more dishes than any other paste and it doesn’t use any unique or special ingredients beyond what I like to call “the basic 10”: dried chiles, garlic, shallots, lemongrass, galangal, cilantro roots, makrut lime zest, white peppercorns, shrimp paste, and salt. Most of these ingredients are used in all of the coconut-based pastes discussed here.

Green - Green curry paste uses similar ingredients to red, with the major difference being its use of fresh green chiles instead of dried red chiles. This gives it a different, fresher flavor that’s unique to green curry. 

Panang - A similar paste to red, panang curry paste is more aromatic because of the addition of cumin, coriander seeds, and roasted peanuts. The peanuts also give panang its uniquely rich sauce.

Massaman - Gaeng massaman is a paste with Muslim roots, evident in the abundant use of dry spices commonly seen in South Asia, like cinnamon, star anise, cloves, cardamom, nutmeg, among others, which makes it an especially fragrant curry. The fresh aromatics that are added to massaman curry paste, however, are similar to red curry paste.

Yellow - Prik gaeng garee, or yellow curry paste, gets its color from turmeric and also curry powder. It tends to be milder in heat and is consequently a good curry to serve to kids.

Water-Based Curry Pastes

Sour curry - Sour curry paste is the epitome of simple curry pastes, since it uses just five ingredients: dried chiles, shallots, garlic, grachai (fingerroot), and shrimp paste, and, as a result, most people will make it at home instead of purchasing a pre-made version.

Jungle curry -  Many people just use red curry paste for jungle curry, but I prefer to make it with a combination of dried and fresh green chiles, which add a bit of a grassy note. (This also means you can make a cheaty version by using a combination of green and red store-bought pastes!)

The Best Methods for Making Curry Paste

Making curry paste is very simple: grind everything together until you have a fine paste. Done! But how do you get all these tough ingredients to break down into a fine, almost homogenous paste?

Traditionally, curry pastes are slowly pounded into a paste in a granite mortar and pestle. But we don’t always have time for that, and over the years I’ve experimented with a variety of different methods, each of which has benefits and drawbacks.

Making Curry Paste With a Mortar and Pestle (Traditional Method)

When using a mortar and pestle, the order in which you add the ingredients makes a difference. Add tough ingredients that are hard to pound first, and pound them finely before moving on to the next ingredient.

If you’re using dried chiles, you have two options for prepping them: You can soak the chiles in hot water first for about 30 minutes, which hydrates them and makes them easier to pound, or you can blitz the dried chiles in an electric spice grinder. The latter method is the only way I do it now, as it’s almost impossible to finely grind dried chiles in a mortar and pestle without soaking them, and I don’t like that you lose some of the chiles’ flavor to the soaking water. One thing to keep in mind with either of these methods is that you can dial down the amount of capsaicin heat in the chile paste by removing the dried chile seeds before pulverizing them.

Here is the order in which ingredients should be added to a mortar and pestle when making a curry paste:

1. Soaked chiles and salt, if using. Using a coarse-grain salt like Diamond Crystal kosher salt will help create friction between the ingredients and the mortar and pestle, making it easier to break down the chiles when pounding. 
2. Fibrous and tough aromatics. Once the chiles are pounded quite fine, add lemongrass, galangal, makrut lime zest, ginger, grachai, etc. Fibrous ingredients should be sliced quite thinly before being added to the mortar; the finer they are to start, the less pounding you’ll have to do. 
3. Softer aromatics with higher moisture content. Once the tough ingredients have been broken down, add softer aromatics like garlic and shallots, which should also be sliced. If you added these first, pounding them would release a fair amount of liquid, which will decrease the amount of friction between the ingredients and the mortar and pestle, which in turn makes it more difficult to break down the hardier ingredients.
4. Finally, anything else that’s already finely ground. If you use a spice grinder to grind dried chiles, this is when you’d add the chile powder; this is also when you’d add ground spices or shrimp paste. You’re just mixing at this point.

Here are a few tips to keep in mind:

• If you want to use the mortar and pestle to pulverize whole, dry spices instead of using a spice grinder, grind them first, remove them from the mortar, and set them aside until you’re ready to add them in at the final stage.
• If after adding garlic and shallots you find the mixture too watery and hard to pound, you can add some of the ground spices to help absorb some of the moisture.
• The most efficient motion to use is an up-and-down pounding motion, not a circular grinding motion. And while pounding in the center of the mortar is necessary at times, don’t forget to use the sides of the mortar, as the friction created between the pestle and the mortar’s walls is very effective at breaking up your ingredients.

The benefits of using a mortar and pestle:

• The amount you make can be as small as you want.
• You can get a very fine consistency with all the flavours released from the herbs.
• Easy to clean.

The drawbacks of using a mortar and pestle:

• You need a heavy-duty mortar and pestle, not those cute marble ones. 
• Takes a long time and it’s a bit of a workout.
• How much you can make is limited by the size of your mortar, and the more you make, the longer it takes.
  

Making Curry Pastes With an Immersion Blender and Coffee Grinder

This is my favorite way of making curry paste. I’ve found it to be by far the most effective way of taking advantage of the electrical appliances I have in my kitchen.

1. Grind the dried chiles and any other whole dry spices in a coffee grinder until they are powderized.
2. Place all other ingredients into a narrow container, like the jug that comes with the immersion blender or a glass measuring cup. Use the immersion blender to blend on the highest speed until everything is ground up fine. You’ll need to lift and reposition the blender as you blend since it’s a very thick mixture.
3. Add the ground chiles and spices and blend just to mix.

The benefits of using an immersion blender and spice grinder:

• You can make a small amount of paste.
• The method yields a fine paste with all the flavours released.
• You don’t need to add any liquid.
• It’s super fast!

The drawbacks of using an immersion blender and spice grinder:

You need a powerful immersion blender, like the ones produced by Breville or Vitamix, for the best results.

Making Curry Paste in a Countertop Blender

If you throw everything into a countertop blender and press go, you’ll find that it won’t blend well because the blades won’t catch on the ingredients without the addition of some liquid. Well, why not just add liquid then? You can, but most curry recipes instruct you to sauté the paste to bloom the herbs and spices in fat as the first step, and if you use a watery paste, you’ll be boiling it for a while before it actually starts to fry. (However, some curries, such as sour curry or nam ya curry, don’t require the sautéing step, in which case using the blender to make the paste works just fine.)

If you’re making a coconut-based curry, I recommend adding some of the coconut milk called for in the recipe and only adding as little as necessary to get the blender going. Then, as you cook the paste down, eventually the coconut oil will separate and the paste will begin to fry in it.

The benefits of using a countertop blender to make curry paste:

• It works well for pastes that don’t need to be sautéd.
• It can handle a large amount of paste.
• It’s very fast.

The drawbacks of using a countertop blender to make curry paste:

• You need to add extra liquid.
• It won’t work for small amounts.
• It can be relatively harder to clean up.

Making Curry Paste in a Food Processor

I don't recommend using a food processor to make curry pastes. The main issue I have with this method is the ingredients are never ground down fine enough for most curries. The herbs get chopped, but not crushed or ground finely so there are remaining cells that have not been broken down and flavors remain trapped inside. 

The benefits of using a food processor to make curry paste:

• It’s fast.
• It works well for certain dishes in which only a rough paste is required. 

The drawbacks of using a food processor to make curry paste:

• The paste is never ground fine enough and flavors are muted.
• You can’t make small amounts of curry paste.
  

How to Doctor Up Store-Bought Curry Paste

Since I had a baby, I mostly buy curry paste, but sometimes the only ones I can find are the basic red, yellow, and green pastes. So what do I do if I want to make a massaman or a panang curry?

Luckily, as I mentioned above, red curry paste is the “basic” paste upon which many other curry pastes are built. So you can use store-bought red curry paste as a starting point, and then add herbs and spices to turn it into something else; you simply grind the ingredients up using the same principles and methods outlined above, and then stir in the store-bought paste at the end.

For example, to make panang curry paste, you can add ground cumin, coriander seed, and roasted peanuts to red curry paste. To make a massaman paste, you add ground cinnamon, coriander seed, cumin, cloves, cardamom, and nutmeg. To make khao soi paste, I mix red and yellow curry paste together, and if I have ginger and black cardamom on hand, I throw some of that in, too.

You can also boost the flavor of a store-bought paste that you consider a bit “weak” by adding more of the spices and herbs it already contains. For example, I find store-bought massaman curry paste to be a bit light on the spices, so I add some extra. If your curry paste doesn’t contain shrimp paste, and many don’t to accommodate people with shellfish allergies, you can add a teaspoon or two. If it’s not spicy enough? Just grind up some extra chiles, fresh or dried and stir them in.

How to Choose a Good Store-Bought Curry Paste

Not all curry pastes are created equal, so here are some tips to making sure you’re buying authentic products:

• Buy them from Asian grocery stores. You can find curry paste at any Western grocery store these days, but it’s unlikely you’ll have a lot of choices.
• Look at the ingredient list. It should list only herbs, spices, shrimp paste, and salt. Avoid anything that lists other seasonings or oils.
• Make sure it’s made in Thailand, which means it uses Thai-grown ingredients.
• If the packaging looks like it’s aimed at the mainstream Western market, the curry paste tends to have milder flavors. Look for a packaging that’s “very Thai,” unless you prefer mild flavors.

I can recommend Maeploy, Maesri, and Aroy-D as good brands with flavors I think of as authentic, and I personally use Maeploy. Thai Kitchen is a brand that’s made for the Western market that’s made in Thailand and has quite good flavor, but you do have to use a lot more of the paste because it’s quite mild.

How to Use Curry Paste

As I mentioned above, while curry pastes are used to make curries, they’re also used in many other ways, including flavoring stir fries, dipping sauces, fried rice, egg custards, sausages, fish cakes. Basically, if a dish can benefit by the addition of a spicy, flavorful, aromatic paste, then you can probably add some curry paste. You can even try incorporating it into non-traditional dishes, like this savory French toast.

There aren’t any rules for what kinds of proteins and vegetables go with specific kinds of pastes, but there are some common pairings. Generally, if the paste has a lot of spices, you want to pair it with heavier meats and sturdy vegetables that can hold up to the richer flavors. For example, massaman and yellow curry are better paired with red meat, dark meat chicken, and root vegetables. Pastes made with just fresh aromatics like red and green curry pastes are more versatile and can work with almost anything. Ultra light pastes made with just a few ingredients, like a sour curry paste, are best paired with delicate items like fish and seafood.

How to Store Curry Pastes

Because curry pastes are made from fresh herbs, you want to keep it in the fridge once they’ve been made or their package has been opened. I recommend freezing your paste—store-bought or homemade—unless you have plans to use it within the next day or two; it’ll preserve the quality and flavours of your ingredients perfectly. Use a heavy-duty container made for the freezer to prevent the paste from absorbing freezer smells too quickly. I pack curry pastes into zip-top freezer bags and then push on the bag with a ruler to create “sections” that help me break off portions easily. Squeeze out as much air as possible from the bag before sealing it up.

If you buy Maeploy or Aroy-D brands which come in a plastic bag inside a tub, keep the open bag inside the tub and freeze the whole tub. These pastes are quite dry and so never freeze solid, so you can just scoop it right out of the jar straight from the freezer