Can you preserve zest? If a recipe asks for zest, I always use fresh fruit. 
I'm wondering if you can preserve it nicely.

I put some in the fridge, but there was some mold after quite a while. I wanted to get rid of the moist, so I put fresh lemon zest in the oven on a low temperature. But I think I left it a bit too long, it's a bit brown now, instead of yellow. However, it still smells and tastes nice, a bit crunchy though. So I'm not satisfied with this result.

Anyone else who has experimented and knows what works or what does not?
Is it possible to preserve zest for months (or even longer), without losing too much flavour?
I've successfully frozen yuzu (a Japanese citrus fruit slightly similar to lemon or grapefruit) zest for two or three months without much damage; the flavor isn't perfect, but it's usable as long as you don't get serious freezer burn. I've kept it in a small Rubbermaid container. There is a potential problem because citrus oils can damage certain types of plastic over time, but this didn't affect me; however, plastic bags won't work so well.