What is this paste I got from boiling down coconut "whey"? I have been fascinated with taking byproducts of a fresh coconut, and this time I got this sweet and very sour paste from boiling down coconut "whey"

First, let me explain what is this coconut whey :


Took the meat out a fresh coconut, did not remove the outer darker skin (Mistake!)
Put the meat with some water on the blender, strained it in a nut milk bag, repeated the process until milk was achieved
Set the milk in the refrigerator for 24h for it to separate
Used the top cream to make butter and buttermilk
The bottom leftover part after the cream was removed is what I call the coconut "whey"


Now, I thought this whey would be mostly water and sugar, so take the water of you have... sugar!

After boiling it down, I stopped when it began to stick in the pan, the end result was a very sticky gooey paste, that at first taste is sweet but then comes a very unpleasant sour, maybe acidic aftertaste, might be due to not having removed the darker outer skin, or maybe due to the lauric acid?

So, any idea what is this? What can I do with it? Did I do something wrong that it became so sour?

I know this isn't the same as coconut sugar you see in stores as that one is taken from the tree not the coconut itself.

Picture (trying to dry it in the oven because its too sticky) :
"Coconut Sugar" is actually made from the sap of the plant, not the nut. Basically, you made a type of "coconut whey paste".  Since it lacked the fiber and most of the oils it was viscous and sticky.  Also, since it included "milk" from the "testa" (Peel of the coconut) it was sour.  

So you reduced the whey down to its: solids + sugar + some testa.  As I said sugar is made from the sap of the tree so I don't know of anyone who has found a use for what you have created.  I would be very curious what you end up with if you peel the coconut before the process.  I would bet it wouldn't be as sour.

With a little more work you are well on your way to a "Coconut Protein Bar" recipe! lol

References:
https://link.springer.com/article/10.1007/s11746-014-2447-9
https://www.researchgate.net/publication/272590676_Composition_of_Coconut_Testa_Coconut_Kernel_and_its_Oil
https://foodcomas.com/2013/03/20/kerisik-coconut-paste/
https://www.healthline.com/nutrition/coconut-sugar