Hydrodynamic stability of burning QCD walls

First order phase transitions in fluid systems can take place through combustion walls in which metastable matter in one phase flows into the wall, releases its latent heat and flows out in the other stable phase. The stability of these walls is discussed and two stabilising factors are identified: One well known, the tension of the interface, and one new, the dependence of the wall velocity on temperature. The results can be applied to the growth of bubblles nucleated in cosmological QCD and electroweak phase transitions. (orig.)