An Interesting Way of Viewing Consumption

"Consumption is the inverse of production, and 'the consumer' the inverse of 'the producer.' To consume, in the economic sense, is to diminish, and in the end to destroy, the utility or 'commodiousness' of a commodity, and 'the consumer' is the person who has legally the final right to do this." -- J.A. Smith, “On Some Fundamental Notions of Economics,” Economic Review, 1913.

This definition helps to illuminate the notion of household production, and clarifies just what are producer goods and what consumer goods. So putting a piece of bread in the toaster is an act of production, and the untoasted bread still a producer's good: the good's utility is still increasing. It is only the toasted and buttered piece that is a consumer good, and it becomes that in the process of having its utility destroyed.