Citrus Salt one of the easiest projects you can do. Living in Southern California here there is citrus year around and plenty to spare. A few things to note if you are a regular preserver is the variety of things you can do with the citrus. It is endless. I will link you to other uses for the left over citrus at the end of this post.
The instructions for Citrus Salt are simple and so very easy. Here is a short list of what you need to make your Citrus Salt.
Take your citrus and zest it so you will have a least a half cup of zest to this you will add a half cup of coarse salt. Mix the two items thoroughly. Spread the mixture onto your parchment covered cookie sheet. The rest is up to nature just let it dry. I place it in my oven with a LARGE note reminding it is in there so I do not cook it.
Oh yes i have done that and even worse left Habanero Seeds kin there and while warming and oven they started to cook I almost ended up in the hospital. Not funny but yes funny!
This Lemon Zest I chopped up so it is easier to sprinkle. I did freeze another container with just zest not chopped for jam's and cooking.
This citrus I chopped up then added the salt. I keep my salt in a mason jar. It is Sea Salt that I use.
When you first put your zest and salt on the sheet it will not be flat on the sheet but as the day's go by you will notice you can mix and it settles together really well. This drying will take probably a week or so.
Make sure the Citrus Salt is dry then transfer it to a air tight container.
I save small glass jar's. Ok ok I save all glass jars and have 5 gazillion from preserving food for so long.
Alrighty that should do ya!
As promised I will give you links to other stuff you can do with all that Citrus.
Freezing Citrus is easy and there are so many ways to freeze it for so any purposes. Marmalade I am linking you to the Preserve Page there are so many Marmalade's to many to list.
A great link on How to Section Citrus. With the pulp and seeds you can Make your own Pectin for Jam. If you are so inclined you can make Preserved Lemons used in many dishes. And you can always when all else fails Dehydrate your Citrus.
Disclaimer: This is not an all inclusive recipe for making jam. You should have a basic knowledge and understanding of the canning process before proceeding. Please consult your local Center for Home Preservation for additional information and available classes