Dissolve unflavored gelatin in cold water and set aside.
In a medium-sized, heat-resistant, non-metallic bowl, heat cream on full power 2 to 2 1/2 minutes or until scalded.
Add dissolved gelatin to cream and stir until completely dissolved.
Stir in sugar, vanilla and salt, mixing well.
Chill until mixture begins to gel.
When gelatin mixture is of desired consistency, whip with rotary beater until light and fluffy.
Add sour cream and beat until thick.
Spoon into 6 lightly-oiled, 6 ounce custard cups or any small cup.
Chill until firm, about 8 hours.