Witbier spices

Does any one have any experience using Orange Marmalade or kumquat skin in a witbier? No local source for bitter orange peel. The Marmalade says rough cut Seville Oranges - sugar - water - lemon juice. The Kumquat peels taste very similar to caracao orange peel.
Thanks,
EMB

I say go for it! You might not get the same effect as bitter orange peel, but you could end up inventing a really good witbeer.

I can't get curacio oranges here either so I've just been using the zest of naval oranges and I'm happy with the result.

Thanks,
I wanted to try to get most of the bitterness from the orange peel or "alternative orange peel". I have had sone nice wits made with sweet orange peel but the hops were increased to compensate for the lack of bitterness in the orange peel. I think the acid in the kumquats could add some authentic sour edge to the wit but I am concerned that the citrus oils and/or astringency may be too strong. I guess I will cross my fingers and hope for the best.
Cheers,
EMB

Apparently the pith (white stuff under the zest) of oranges is really bitter and isn't added to the beer. If you have sweet oranges then maybe you could add a bit of that.

I haven't tried it though....