How do I prevent coconut milk from separating in Thai curry?
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).
- Stir some of the paste with a can of coconut milk (I've been using Chao Koh) until that boils.
- Add some fish sauce and chicken broth along with the meat and vegetables
- 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?
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.
A heaping teaspon of tapioca powder works very well for rescuing broken coconut milk sauces.
I'm not convinced about the cream + boil = separated formula. When I have a cream based sauce in the oven at 350F (180C) for 45 minutes, it certainly boils but does not separate.
In my experience boiling the coconut milk is not a problem. I had Thai cooking lessons and the instructor boiling the living daylights out of the coconut milk for 10 minutes - and still produced a great curry. You want to add plenty of water/stock after cooking the coconut milk to make a watery sauce.