How do I prevent coconut milk from separating in Thai curry?

Question

It seems like every single attempt I've made at making a Thai-style coconut curry ends up with the sauce mixture separating. Although it usually still tastes good, the coconut ends up looking like it has curdled.

My question is what could I be doing wrong? I've mainly been following the recipe on the side of the curry paste I have (Thai Kitchens brand, IIRC).

1. Stir some of the paste with a can of coconut milk (I've been using Chao Koh) until that boils.
2. Add some fish sauce and chicken broth along with the meat and vegetables
3. Simmer until cooked.

My suspicion is I may be using too much chicken stock. I usually use about 1-2 cups. The vegetables I add(typically bell peppers and onions) will also contribute additional liquid to the curry.

My family and I love this dish, but I would really like to perfect its preparation. What steps can I take to prevent the coconut milk from separating from the curry?

Answer 1

Even though it isn't really milk (in the dairy sense), coconut milk still naturally separates into a thick cream and thinner liquid like regular milk. As such, when working with coconut milk you should still follow the same procedures you would to make a milk-based cream sauce.

The number one rule when making any creamy sauce is: DON'T LET IT BOIL! Boiling will guarantee that your creamy sauce (including sauces made with coconut milk) will break in some form or fashion. At most, you should cook these at a bare simmer.

Other than that, there are some techniques you can use to keep your curry smooth.

You could use an emulsifier like honey (common in vinaigrettes, where it is used to make sure the oil and vinegar don't separate), added toward the end of cooking.

You could also use a thickening agent, like a cornstarch slurry or a quick roux. Curry paste is also a thickening agent. As a general rule of thumb, when making Thai-style curry I usually cook my vegetables in a little more oil than I think they need, then add the curry paste and sauté that until it has absorbed the oil (along with any dry spices). It will act as a roux for the coconut milk and make sure there are no lumps in the final curry.

Lastly, cooking the curry uncovered at a simmer, stirring occasionally, will thicken it up nicely and help all the ingredients stay together.

Answer 2

If ever you need to add milk to a hot dish it is likely to either curdle or separate.
The trick is to take some of the hot liquid, a couple of spoons should do, and put it into a small bowl. Now let it cool down a little. Then you add the milk to the warm liquid in the small bowl and beat it with a fork. The two liquids should incorporate without separating. You can then add this beaten liquid back to your hot dish while beating or stirring the gravy or curry all the time.
This technique works for both fresh and coconut milk as well as for yogurt.

Answer 3

When I make Thai dishes, the coconut milk goes in right at the end.

I generally make my own curry paste, and it goes into the pan first after the oil is hot. The vegetables/meat/other stuff go in afterwards. Once those are all done to your satisfaction, you add the coconut milk.

Turn the flame off before it boils, and you should be fine.

Answer 4

Don't boil it

There are many reasons why it might separate, depending on ingredients, but the obvious one is not to boil it, just simmer it after all other solid ingredients are nearly/fully cooked to your liking

Answer 5

I'm disappointed to see the answers to your query. They're way off the mark.

OK - firstly, you want to get the oil to separate when cooking the coconut cream in Thai cooking. Without that, you end up with a smooth, creamy sauce which just isn't the authentic way to do it at all. That's the standard beginner's mistake. You can use the heavy cream (the harder top of an unshaken can of coconut milk) to start with, let it bubble so that the oil starts to separate. You can then add your paste and continue to fry it for a couple of minutes and then add the rest of the milk. Yes - you DO want the milk to boil lightly. You need to add the fish sauce at this point, anyway.

Plenty of authentic examples to show you the process on Videojug, if you want to take a look there.