Making myself a 1 gal batch of this right now. I am mainly going off of your recipe alhiem, but I subbed a few items.
First, I decided 20g of bark since the first recipe calls for 1 oz (28 g), but yours only calls for a few pieces. Second, I used 1/2 tsp dried Mediterranean oregano instead of marjoram, and 1/4 tsp of tarragon instead of star anise. I backed off on these two because I know oregano is much more pungent than marjoram, and for the star anise, I really dislike the licorice flavor, so I backed that off quite a bit.
I also used 260g of each of the brown and cane sugars to be more precise than the volumetric measurements. The liquid reads 16.4 Plato, which comes to 1.067 specific gravity. I'll add a teaspoon or two of US-05 yeast when it cools down enough, and see what happens.
Wow. It must have tasted awful.. I never make my mavi like that! As a matter of fact one does not even need to add anything just the mavi bark which one can buy on EBay. I do use one stick of cinnamon and a little ginger but I have done it without it and it comes out tasting great. That second recipe is not from Puerto Rico.. The first one is the one I do. Mavi needs full hot sun days. I place it out on my porch for 3 to 4 days in which it ferments. I make a hole on the bottle caps and as it ferments it foams and the foam is the bitterness of the bark. The finished product is sweet as honey.