I don't think you dried them, I think you slow-cooked them. Probably better to blanch them and then dry in a dehydrator, or air dry.
(Blanch - drop into boiling water for 2-3 minutes. Most veggies to be dried or frozen need to be blanched.)

 

Sounds like you slow cooked them.
I slow smoke chipotles, once done dehydrate (a long time).
Then package in mylar (w/02 absorbers) whole or ground to powder.

 

We string them on thread and needle then hang in doorways to dry. Takes a few days but its effective.

 

I always let the peppers turn red, yellow or what ever the age color is on the plant and are on the soft side. I then move them to a cookie sheet withe a paper towel on it and let them dry out in a sunny window. It takes some time, but I've never had a problem doing it that way. The stem should be left on when doing that..

Il add them to dishes whole or ground up.

 

Growing up in Arizona the Natives just toss them (by the hundreds) on the roof for a week and let God do the work. I lay them on screens laid across saw horses out in the yard.

No idea why they would taste horrible, even if you did slow cook them. Did they taste good BEFORE you dried them? Perhaps they always tasted horrible and you got a bad batch.