Homemade coconut milk in coffee compared to store bought
Are you talking about canned coconut milk, or the newfangled coconut "milk" beverage in cartons, meant as a non-dairy replacement for milk, like So Delicious and Coconut Dream? The latter is formulated specifically to taste and behave as close to dairy milk as possible. The (tri)calcium phosphate not only fortifies the milk, but also buffers it and makes it behave and taste more like real milk. Non-dairy coffee creamer and cheap half &amp; half have dipotassium phosphate or similar phosphate salts for the same purpose.

I don't know if I can suggest anything to help. If you try regular canned coconut milk (with no dilution, stabilizers, or fortification), is it any better than your homemade coconut milk? You might try experimenting with heating your coconut milk, or adding small amounts of salt and/or sugar, or blending the warm coconut milk to better emulsify it.