a cryogen - blanching technique involves brief exposure of an oyster shell to a cryogen . the cryo - blanching weakens the oyster &# 39 ; s muscles that close the bivalve tightly shut , but preserves the natural condition of the bulk of the oyster meat . the weakening of the oyster &# 39 ; s holding muscles allows shucking the oyster meat in its fresh or natural state without damage or shell fragments .