A method for producing cis,trans- and trans,trans-isomers of muconate by providing cis,cis -muconate produced from a renewable carbon source through biocatalytic conversion; isomerizing cis,cis-muconate to cis,trans-muconate under reaction conditions in which substantially all of the cis,cis-muconate is isomerized to cis,trans -muconate; separating the cis,trans-muconate; and crystallizing the cis,trans-muconate. The cis,trans-isomer can be further isomerized to the trans,trans-isomer. In one example, the method includes culturing recombinant cells that express 3-dehydroshikimate dehydratase, protocatechuate decarboxylase and catechol 1,2-dioxygenase in a medium comprising the renewable carbon source and under conditions in which the renewable carbon source is converted to 3-dehydroshikimate by enzymes in the common pathway of aromatic amino acid biosynthesis of the cell, and the 3-dehydroshikimate is biocatalytically converted to cis,cis-muconate.