Fried Chicken Thigh skin always ending up soggy? Why?

Question

I am making Japanese style fried chicken, so I'm using chicken thigh with skin on, bone out. My problem is the chicken skin on the fried chicken is always ending up soggy. I've searched the web for some info, and some says it is because the oil is not hot enough. Or could it be that my cooking time is not enough, making the skin soggy?

My chicken thigh are as follows:

1. Sliced into 2 inches cubes.
2. Not battered, just starched with sweet potato starch (unsifted) after marinated for 30 minutes to 1 hour. Marinade used is salty, 2 tablespoon soysauce and 1 teaspoon salt.
3. Is at room temperature (not coming from the fridge) when fried. My usual method involves frying 4-6 pieces at a time on 330F for 1-2 minutes placing them on a cooling rack to settle down. Afterwhich, I fry again a second time on 356F for a minute or so until it's golden brown placing them back on a cooling rack. Cooking time is suggested in one of the recipes I found online.

I tried experimenting with 350F initially for 1-2 minutes, and second fry at 360-370F at a minute or so. Somehow this improved the crispness but still not quite as expected and somehow the outer layer tastes like burnt starch but not really burned (outer color is dark golden brown). Any deep frying expert here can shed some light? I'm at my wit's end.

Answer 1

Tried making another batch today and here's what happened:

First Test: I used potato starch (was finally able to get hold of the starch), and used that instead of sweet potato starch, true enough the result was perfectly crisp and crunchy similar to that of potato chips!

Second Test: Used the same old starch (sweet potato starch) and skin turned out soggy like before.

Third Test: Mixed potato starch and sweet potato starch, it improved the crunch but still skin is soggy due to sweet potato starch.

Conclusion: The starch and not the marinade is causing the chicken skin to become soggy.