I am doing a cost accounting project about costing out Wendy's chili and was wondering how I could account for the joint cost of the Hamburger in the Chili.

Facts:
90% of the time the chili is cooked from overdone hamburger that cannot be sold as "hot and juicy" and would otherwise be thrown away
Chili accounts for 5% of total revenue while hamburgers are 55%

I don't think you could account for the hamburger as a byproduct in the chili even though it is using the scraps from the hamburger. I have never seen a byproduct be able to be processed farther either.

I am still on the fence though because you are using hamburger scraps that would be thrown away. If I allocated it as its own product would I only allocate the 10% of the hamburger that they actually intend to use for Chili and see the other 90% as a "sunk cost" in hamburgers anyways?

If you could just explain how you would allocate the hamburger cost that is in the chili as a joint cost that would be great!