Essential Thai Condiment: Chili Vinegar (prik nam som)

If you’ve ever been to Thailand you will notice all kinds of little sauces and sprinkles that often come with our food. One of those sauces is and absolutely essential condiment of Thai cuisine, especially for our noodle dishes: chili vinegar or prik nam som พริกน้ำส้ม.

It adds an acidic zing with a little bit of heat, and when used in the right places, it takes a dish to the next level. And for some dishes, like pad see ew and boat noodles, a dash of prik nam som is absolutely necessary!

What is prik nam som?

Prik means chlies and nam som means vinegar, and in its simplest form, that’s all there is: chilies mixed with plain old white vinegar, though you can get a little fancy, and I’ll show you how to do that too.

It’s a spicy, vinegary sauce that we use on any dish that’s heavy or oily, with a flavour profile that's salty and/or sweet because the acid and heat helps cut the grease and balance the sweet and saltiness.

We use it on dishes like pad see ew, pork leg stew with rice (kao ka moo), rad na noodles with gravy and boat noodles. In fact you can use it on any kind of noodle soups, and you can use it wherever you’d want to add a vinegary hot sauce, even if it’s not Thai food!

In Thailand, if you order any of the dishes I mentioned above, there will automatically be prik nam som served with it, if it's not already sitting on the table. In Thai restaurants overseas, however, you will probably have to ask for it, but they may not have it available. Many Thai restaurants omit these condiments to simplify things.

Ingredients and Notes

Here are a few important notes on the ingredients. For amounts, see the full recipe card below.

• Thai Chilies. I use Thai chilies but any kind of spicy fresh chilies will also work. You can use either red or green, but I personally prefer the flavour of red chilies as they are fruitier.
  If you want a milder chili vinegar, you can remove the seeds and pith from the chilies, or use milder chilies (e.g Fresno) to start with.
• White vinegar. We only use white vinegar for prik nam som because the idea is to add neutral acidity, not to introduce new flavours. While milder vinegars such as Filipino cane vinegar or rice vinegar will be fine, don't use apple cider vinegar or anything else that has a distinct flavour. NO balsamic!
• Garlic. This is totally optional, only if you want to make it a little more complex! Most of the time I just stick with chilies and vinegar.

How to Make Chili Vinegar - 4 Ways

There are several variations of prik nam som in Thailand, and here are the 4 most common ones. I'm showing you how to make them in a mortar and pestle, but for large amounts, you can put everything into a blender.

1. Basic Prik Nam Som

1. Pound chilies in a mortar and pestle until mostly fine.
2. Add the vinegar and swirl the pestle to mix.

2. Charred Prik Nam Som

This version uses charred chilies which not only adds smokiness but also make it a bit sweeter as the chilies will be cooked. You can char the chilies more than what's shown in the image for extra smokiness.

1. Char the chilies on a dry hot pan until they develop charred spots all around.
2. Pound until fine in a mortar and pestle then add vinegar and mix.

3. Garlic Prik Nam Som

Whether you decide to do the basic or the charred prik nam som, you can also add garlic for a more complex flavour. You can even char the garlic along with the chilies if you're going that route. Notice in the photo above I used seeded chilies, which you can do if you want to tone down the heat.

4. Sliced Prik Nam Som

In Thailand you may have seen slices of chilies in clear liquid on the table, that's also a kind of prik nam som. Instead of blending the chilies, they are sliced, resulting in a quick chili pickle. Typically milder chilies are used, such as spur chilies, but you can use any kind of chilies. Pictured are serrano chilies.

Simply let sliced chilies sit in the vinegar for at least 15 minutes before using. You can eat the pieces of chilies if they are mild enough, or drizzle just the chili-infused vinegar onto your food.

Storage

Prik nam som can be stored in the fridge in a sealed container indefinitely. It can also be frozen. I would stick with glass containers as over time the chilies can stain plastic. Also, stay away from lids that are made with reactive metal, such as aluminum mason jar lids, as the acid can corrode it.