Does dairy (e.g. crème fraîche) spoil faster if using the same spoon in older and newer product?
Food in general spoils when bacteria, fungus, and other little bugs eat the food, multiply into more, create waste, and then die. I would imagine that the increased population of "bugs" found on a old, used, not washed spoon would cause the decomposition of new creme fraiche to accelerate, but if you wash the spoon, then no-problem.