we bought a lot of ice cream.

the last serving of ice cream in the carton tastes like cardboard. it will be left alone.

As a family of five, we bought a lot of ice cream. There were parent flavors and ice cream for the kids. No matter what ice cream tickled my father's fancy that day however, if there was ice cream an inch from the bottom of the container, it was put back. Or if he got himself ice cream and realized that he was nearing the bottom, instead of topping off the perhaps 1/4-serving left, he put it back the the freezer for someone else to finish off. The reason? The ice cream on the bottom tastes like the carton.
My father had it down to a science: you see, when they package ice cream, it's still soft. So as the ice cream is freezing, the container taints the flavor of the ice cream. Of course, the sides are not affected by this because in the freezing process, the cream also rises to the top. This is why you can scrape the ice cream off of the lid and it is fine, but the bottom of the container has lost the cream and is being tainted my the carton.
If the ice cream even looked like it was getting low (about 3/4 down), my father would insist that we have a new carton of ice cream (unless it was a flavor he didn't eat). The new carton would be opened, the "tainted" ice cream untouched, and my mother or us kids would have the duty of finishing it off in order to make room in the freezer.