Why does soup have skin on the top?!

Question: layer of fat

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Answers: layer of fat

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I work for a soup factory so I can answer this question quite easily.

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It the grease from the meat and broth.

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Its because its SKIN SOUP ,why else?

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I think it's the starches coagulating on the top. If you have a brothy soup it doesn't form a skin but if you have a creamy soup it does, same thing happens with cooked pudding.

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