Melt in a water bath, the squeezed gelatine in a small saucepan with a little bit of buttermilk.
In a bowl, combine the remaining buttermilk, powdered sugar and the lemon juice and the gelatin dissolved to give. The cream until stiff and fold into the buttermilk cream.
The molds or teacups, rinse with cold water, pour and chill in the refrigerator for at least two hours. Turn out the buttermilk cream on the plate.