Coconut milk looks like water with butter chunks
There can easily be some confusion regarding the terms cream of coconut, coconut milk, coconut cream, coconut water etc. It is normal and even often desirable for coconut milk to separate, and for the fattier part (the cream) to clump. Since that is generally not a great quality for mixed drinks, read on.

For Pina Coladas, the most commonly used product is Cream of Coconut, the sweetened, emulsified variety. Two common brands in the US are Coco Lopez and Goya. Coconut milk and coconut cream are totally different products from each other and from cream of coconut, so read the label carefully. When in doubt, check the ingredients. The product you want will have added sugar and emulsifiers.

Goya Cream of Coconut ingredients:


  Ingredients: Coconut Juice, sugar, polysorbate 60, salt, citric acid, mono and diglycerides, propylene glycol alginate, sorbitan monostearate, guar gum and locust bean gum.




Coco Lopez Cream of Coconut ingredients:


  Coconut, Sugar, Water, Polysorbate 60, Sorbitan Monostearate, Salt, Propylene Glycol, Alginate, Mono and Diglycerides (Emulsifiers), Citric Acid, Guar Gum, Locust Bean Gum.




These products will not clump like what you have experienced.

In grocery stores in the US, cream of coconut will be with other bartending mixers like margarita mix, not anywhere near the coconut milk. If you have any problem finding it, ask at a liquor store.