Agree with your comment about questionable origin. The one and only time I bought Costco’s rotisserie chicken the meat was layered with thick globules of fat. As do you, I recommend staying away from Costco’s rotisserie chickens.
I have to wonder if e-s was referring to the insectoid origins of Costco fowl.
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That “fat” that you discovered in the meat is not likely even chicken fat.
Chickens store their fat just under the skin, and that fat is quite healthy to consume, but the stuff in the muscles is not normal.
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