Coconut milk is essential in the kitchen, especially if you cook Thai curries at lot. I have often found that it splits, even if the cooking temperature is low. The result still tastes lovely, but it doesn’t look very appealing.
The key is the use of chemical emulsifiers and stabilisers in the brand of coconut milk you buy such as guar gum; emulsifiers bind and stabilise so splitting does not occur. Some brands contain these emulsifiers, but some do not. If they don’t, when you open the tin, you will notice that the coconut cream and the coconut water are separate and need to be mixed together.
This is the kind I prefer to use, as I like to use the coconut cream a lot. If this is your preference, you may find that the mixture often curdles and splits as you heat it.
The solution is very quick and easy. Simply add 1 tablespoon of cornflower per 400ml (a normal sized tin) to stabilise the mixture. Make a thin paste by adding a small amount of the coconut milk to the cornflower, then add to the mixture and cook through.
This mixture will now be stable and will not split or curdle as you heat it. Make sure you cook out for at least 10 minutes to avoid any floury taste. This trick will also work if the mixture has already split.