We study the stability of hot strange matter lumps formed in the early
Universe. As the Universe cools below the hadronization temperature,
these lumps normally become unstable against boiling. They can stabili
ze themselves against this process if their mass is sufficiently large
to hold a hadronic crust by gravitational attraction. Our analysis im
proves on previous studies of the internal structure of such stable ho
t quark matter lumps with hadronic crust by correctly treating the con
straints from chemical equilibrium of baryonic and electric charge bet
ween crust and core. Since the expansion rate of the early Universe is
much faster than the cooling rate of the strange matter lumps, their
internal structure is characterized by constant entropy per baryon. Ou
r improved analysis confirms the earlier finding that such stable quar
k matter lumps require a mass well above the total mass inside the hor
izon.