Universality of multiplicative infinite loop space machines

We establish a canonical and unique tensor product for commutative monoids and groups in an 1-category C which generalizes the ordinary tensor product of abelian groups. Using this tensor product we show that E n -(semi)ring objects in C give rise to E n -ring spectrum objects in C . In the case that C is the 1-category of spaces this produces a multiplicative infinite loop space machine which can be applied to the algebraic K-theory of rings and ring spectra.