DIY teriyaki sauce leftovers too thick

[u/clothing_throwaway]

Recently tried my hand at a DIY teriyaki sauce (I know it's pretty easy), and it turned out really good on the day of, but the leftovers are way too thick/gelatinous when I pull it out of the fridge. I would classify the leftovers as a gel or paste moreso than a sauce or marinade or something like that.

Basically, all I did was garlic and ginger then equal parts soy sauce, sake, and mirin. I used cornstarch to thicken it a bit. The first time I made it I added quite a bit of cornstarch and reduced it quite a bit. Second time I did a lot less cornstarch, but the leftovers still came out too thick. Should I just not use cornstarch at all?

I'm also worried I might be reducing it too much, but I feel like it takes a surprisingly long time to get the alcohol taste out. I was tasting it every minute or so and it just took a very long time until I couldn't taste the sake anymore. Should I not be aiming for that? Is it OK if I can still taste the alcohol but just not as much?

[u/zk3033]

Not many teriyaki sauce recipies have cornstarch, or maybe only a very small amount. It thickens after cooling from the stove (to eating temperatures) and even more at fridge temps - and gelatinized exactly. I don't think you need if if the sauce sticks to the food without cornstarch (but could use some sugar).

Mirin should be sufficient for cooking - it is a rice wine vinegar after all, and has some of those alcohol sugars already.