At the heavy ion storage ring CRYRING in Stockholm, Sweden, we have investigated the dissociative recombination of DCOOD{sup +}{sub 2} at low relative kinetic energies, from approx1 meV to 1 eV. The thermal rate coefficient has been found to follow the expression k(T) = 8.43 x 10{sup -7} (T/300){sup -0.78} cm{sup 3} s{sup -1} for electron temperatures, T, ranging from approx10 to approx1000 K. The branching fractions of the reaction have been studied at approx2 meV relative kinetic energy. It has been found that approx87% of the reactions involve breaking a bond between heavy atoms. In only 13% of the reactions do the heavy atoms remain in the same product fragment. This puts limits on the gas-phase production of formic acid, observed in both molecular clouds and cometary comae. Using the experimental results in chemical models of the dark cloud, TMC-1, and using the latest release of the UMIST Database for Astrochemistry improves the agreement with observations for the abundance of formic acid. Our results also strengthen the assumption that formic acid is a component of cometary ices.