You had to heat it up to make it eat able.I had fashioned a stove from a clothes hanger and used my Zippo lighter to warm it up. If you were fast it was palatable.
Most of the C-rats were quite edible when warm. But cold beef and potatoes in the field in winter was real hard to digest. Oldest C-rats I saw had a 1952 date on the case.
Ham and eggs was my favorite, even cold.